Editor’s Notes: In this episode of The Diary Of A CEO, Steven Bartlett sits down with biomedical scientist and anti-aging expert Dr. Rhonda Patrick to explore the cutting-edge science of health optimization and “peak span.” Dr. Patrick reveals the hidden environmental toxins—from receipts to plastic containers—that disrupt our hormones and accelerate aging. The discussion provides actionable strategies for shrinking visceral fat, reversing heart aging, and using tools like continuous glucose monitors to fine-tune your metabolic health. This deep dive is an essential guide for anyone looking to maintain peak physical and cognitive function well into their later years. (March 30, 2026)
TRANSCRIPT:
The Yellow Blob: What Is Visceral Fat?
STEVEN BARTLETT: Dr. Rhonda Patrick, I am fascinated by so many of the things that you talked about and they’re front of mind for me at the moment because I’m a 33 year old man and I know from doing this podcast and looking at graphs like this one, which we’ll talk about today, which I don’t think most people have ever seen in their lives, that this is the age where things might start changing direction from here on over the next decade.
And there’s things I can do to set myself up now if I listen to your advice, for the remaining decades of my life to be remarkably different. I’m playing with this in my hands at the moment. It’s for anyone that can’t see. You should probably look at the screen right now. It’s a yellow blob of squidgy, slightly disgusting material. What is this and why does this matter?
DR. RHONDA PATRICK: So this represents visceral fat. It’s something that most people haven’t heard of. Many people have heard of fat. They know fat is bad, but they don’t realize there are different kinds of fat. There is visceral fat and this is the kind of fat that you can’t really pinch. Adipose tissue kind of fat. I mean, if you opened up your body, you could pinch it because it’s deep, deep within your body. It’s often referred to as belly fat. And it’s surrounding your organs like your liver, your kidney, your intestines. This is a very deep belly fat and it’s very different from subcutaneous fat. You can actually be lean but have a high amount of visceral fat. We call these metabolically unhealthy people.
So visceral fat — you mentioned you’re 33. The average 33 year old male has how much visceral fat?
STEVEN BARTLETT: According to the data, it says roughly 1.2 pounds at the age of 30. And then for a woman, 0.5 pounds of visceral fat at the age of 30. At 40, it’s 1.7 pounds for a man and 0.7 pounds for a woman. At 52, 2.2 pounds for a man, 1 pound for a woman, and at 60, 2.7 pounds of visceral fat and 1.54 pounds for a woman, which is the highest risk for metabolic syndromes at that age. But I mean, all of them are pretty scary.
The Dangers of Visceral Fat: Cancer, Inflammation, and Early Mortality
DR. RHONDA PATRICK: It is. And as you notice, the trend is as you get older, you have a higher risk of having more of it. 70% of women over the age of 50 have a high amount of visceral fat. 50% of men over the age of 50 have a high amount of visceral fat. This visceral fat, for one, it’s going to double your risk of early mortality. Full stop. It’s going to double your risk.
STEVEN BARTLETT: Double your risk.
DR. RHONDA PATRICK: Double, double. Visceral fat is, as I mentioned, different from the other kind of fat, the subcutaneous kind of fat, the adipose tissue kind of fat, in several ways. One is that it is metabolically active. It is secreting inflammatory cytokines. These are molecules that are signaling to the immune system, but they’re also involved with damaging our cells. And for this reason, people with a high amount of visceral fat are 44% more likely to get metastatic cancer. That’s cancer that’s going to metastasize. Very dangerous types of cancer.
They’re also more likely — you mentioned metabolic syndrome. This is a big, big thing with visceral fat. This type of fat is constantly breaking down triglycerides into free fatty acids. It’s constantly doing it.
STEVEN BARTLETT: What’s triglycerides?
Insulin Resistance: How Visceral Fat Disrupts Your Metabolism
DR. RHONDA PATRICK: Triglycerides are how your body is able to store fatty acids and fat and use them for later energy. So they’re constantly breaking them down and using them. They’re using these fatty acids. But typically what happens in your body when you eat a meal, you have your glucose levels go up, your blood sugar elevates, your glucose levels go up and that signals to the pancreas in your body to make insulin. Insulin is this hormone that plays a role in many things. One of it is to tell different parts of the body to take glucose up, like your liver, your muscle, your adipose tissue.
Well, the problem is this visceral fat is constantly making those free fatty acids. And so those fatty acids — this type of fat doesn’t respond to insulin. So whereas the subcutaneous fat will stop breaking down fat and using fat as energy, it says, “Okay, look, I have energy here. I’ve got to do something with this energy. Let me store it for later use.” Well, that doesn’t happen with visceral fat. What happens is it just keeps going, keeps going, keeps going.
What happens is when your visceral fat is metabolically active like that, it is basically making it where insulin can’t work its job. And so what happens is that glucose can’t go into your liver. It stays in your blood system.
STEVEN BARTLETT: And you really want it to be stored in your liver, right?
DR. RHONDA PATRICK: You want it to be stored in your liver as glycogen, to be used as energy when you’re fasting or when you’re physically active whenever you need it.
So what happens is your body freaks out because it’s not good to have glucose sitting around in your bloodstream for a while. It causes a lot of damage. And so what happens is your body makes even more insulin to try to overcompensate. Your body goes, “Oh, maybe that wasn’t enough insulin, because the glucose isn’t coming in to the organs like the liver like it’s supposed to. So let me put some more out.”
STEVEN BARTLETT: And for anyone that doesn’t know, insulin is kind of like the taxi driver that goes and picks up the glucose and takes it home to the liver, right?
DR. RHONDA PATRICK: Exactly. It’s taking it home, it’s taking it back to the liver. And so what happens when you make more insulin? You’re overcompensating in such a way that now glucose really does get taken up into these other organs like the liver, and so much so that it causes your blood glucose levels to go down and you’re crashing.
All of a sudden this is responsible for that — people that eat a meal and they’re kind of insulin resistant, they eat a meal and then all of a sudden they’re crashing an hour later. “Why do I have no energy? Why am I hungry?” Because after you crash, your blood glucose levels go down. That’s what I mean by crashing — really far down, not normal levels, but below that. And so then your body tries to overcompensate by going, “Oh, I’m hungry, I need to eat.” And so you start to have these cravings for energy dense foods. And that’s part of this cycle of the beginnings of insulin resistance.
So when I’m talking about here with visceral fat, it causes insulin resistance and that’s essentially the take home here. By constantly metabolizing fatty acids, it’s stopping that taxi car from going and getting the glucose. It’s not happening, it’s not responding. You’re not picking up the driver.
And so you become insulin resistant. And that has a lot of problems. One, it’s going to affect your immediate energy levels, it’s going to affect the way you’re feeling, and two, it’s going to make you more likely to become type 2 diabetic because eventually your body won’t be able to produce enough insulin to bring the glucose in. And so then you become type 2 diabetic. So that is a big consequence of having this visceral fat.
In addition to those inflammatory molecules that are being generated from this fat, it’s just so metabolically active. And that inflammation that you’re generating not only does things like raise your cancer risk by 44%, it also makes you tired. It gives you brain fog, lethargy. When your immune system is being activated by this inflammation, you’re taking energy away from your brain. It’s a lot of energy to activate your immune system. So that energy is now going to the wrong place. It’s not going to your brain.
STEVEN BARTLETT: So you won’t feel cognitively as sharp.
DR. RHONDA PATRICK: Absolutely not. Just think about when you have an infection, your immune system is very active. You’re fighting off a pathogen. Do you feel like you’re tired or do you feel like you’re cognitively at your peak?
STEVEN BARTLETT: Yeah, I’m like, I’m out of action for several days usually.
DR. RHONDA PATRICK: Right. You’re tired and your brain isn’t working. And part of that reason is because your activation of your immune system is sucking energy away from your brain. And the other reason is because the inflammation being generated gets into the brain and disrupts neurotransmitters and things like that. So it’s like a double whammy. Your brain isn’t working properly.
And so there’s a lot of people walking around constantly feeling tired, feeling lethargic, feeling brain fog, and they might have a high amount of visceral fat and not even know it.
How to Measure Visceral Fat
STEVEN BARTLETT: So, typically, looking at the data, most people have too much visceral fat.
DR. RHONDA PATRICK: Most people do have too much visceral fat. And typically, a really high amount — a proxy for it would be measuring your waist circumference. So if women have a waist circumference of 35 inches or greater, that is a sign of too much visceral fat. If men have a waist circumference of 40 inches or more, that is a sign of too much visceral fat.
Ideally, you would go and get what’s called a DEXA scan. Now, this is not something that’s routinely done, and it doesn’t necessarily have to be done unless you’re that person that really likes to go the extra mile and directly measure things. That would be another way to do it. You really want to have below 300 grams of visceral fat. Ideally closer to zero the better.
STEVEN BARTLETT: Me and my friend went and got a DEXA scan done. And the remarkable thing is I weigh a lot more than him and I’m much bigger than him. He’s skinny. But after the DEXA scan, they said that he had too much visceral fat, which I thought — I thought you must be, like, big or obese to have visceral fat. But he’s a skinny guy. And the DEXA scan said too much visceral fat.
Skinny but Metabolically Unhealthy: The Hidden Risk
DR. RHONDA PATRICK: Yes, that’s the thing. I was involved in clinical research for many years when I was doing my postgraduate training, and we were looking at populations of people that were metabolically unhealthy or maybe overweight obese in some cases. And you would have someone come in that they looked skinny, they looked like they were metabolically healthy because they weren’t overweight. And yet all of their biomarker data was showing the opposite. Like, if you would have shown me their metabolic data, I would go, “Oh, this is an overweight obese person.” So these are lean but metabolically unhealthy people. And a large percentage of that has to do with an increase in visceral fat.
You won’t even necessarily know that you’re getting higher amounts of visceral fat. It’s not necessarily going to be reflected on the scale. You mentioned maybe a pound, maybe a little bit more. That’s like daily fluctuation in some cases. I mean, I can fluctuate a pound from day to day for sure. If you’re talking about 500 grams or less, that’s not going to be reflected on a scale either.
What Causes Visceral Fat? Diet, Hormones, and Sleep
You might be going, “Well, what’s causing visceral fat?” I mentioned age. That’s a big one. Hormones is a big one. Women are very susceptible as they go through perimenopause and menopause, because estrogen actually helps tell the body how to store energy. And it tells it to store energy and fat in adipose tissue, not viscerally. So when your estrogen starts to go down during perimenopause and then menopause, women really start to gain a lot of this belly fat. They gain a lot of the visceral fat.
Testosterone also — it doesn’t tell the body how to store the fat so much. It helps you burn visceral fat. So men are a little bit more protected when they’re younger as well. But as they age, of course, testosterone goes down as well and that affects the visceral fat.
But mostly it’s our diet and our lifestyle that’s really affecting visceral fat. It’s kind of mind blowing how quickly you can gain visceral fat. Sleep is a big one. When you miss sleep, that is something that can really cause you to start to gain visceral fat very quickly.
There was a study in healthy young men. These men were sleep restricted. Typically when sleep restriction studies are done, you’re looking at four hours of sleep per night. So pretty severe — not out of the ordinary. I did many of those: college, graduate school deadlines, definitely as a new parent. Unfortunately it drags on for months. So these men were only sleeping four hours a night for two weeks. These were healthy young men, college aged students. They gained 11% visceral fat after that two weeks. But not a pound on the scale. They had 11% higher visceral fat after just two weeks of not getting enough sleep.
STEVEN BARTLETT: And they weighed the same pretty much. So it was the composition of their body that’s shifting.
The Dangers of Visceral Fat and Insulin Resistance
DR. RHONDA PATRICK: Yes. Also the visceral fat, like I said, you’re not gaining pounds and pounds and pounds of it necessarily. You’re gaining grams and grams, but it’s happening. And any amount that you’re starting to gain is unhealthy, right? It’s going to start causing insulin resistance. It’s going to start causing fatty liver. That’s another thing it does because it’s around the liver. Basically the liver doesn’t know what to do with all the fat, so it starts to make and store it around the fat. And so you start to get this non-alcoholic fatty liver, which is happening now in young people.
So sleep is one another major, major lever for gaining visceral fat. Your diet quality and quantity is another. So if you start to be in a caloric excess constantly, you can start to gain visceral fat. And that’s also been shown in studies.
So there was a recent study that again was in healthy young men given about 1,200 extra calories a day, and it was mostly from ultra-processed foods. I mean, they’re 1,200 calories — so like a Big Mac and a Coke, Big Mac and fries, whatever. So you’re talking about almost like an extra meal a day from ultra-processed foods. For five days they were given this extra caloric intake. After that five days, they started to gain visceral fat. They started to have signs of fatty liver after five days, and their brains became insulin resistant. And this is important.
STEVEN BARTLETT: How many calories were they having in excess?
DR. RHONDA PATRICK: 1,200–1,500.
STEVEN BARTLETT: In excess.
DR. RHONDA PATRICK: More than what they were usually going to eat. Yes.
STEVEN BARTLETT: Okay.
DR. RHONDA PATRICK: Yes. A lot of people are eating caloric excess daily, they’re not exercising, there’s no energy expenditure, and they’re eating more. Now this is the extreme end — I’m giving you an extreme end because that’s what they do usually in studies like this, because they want to get a significant result. But after five days they were gaining visceral fat, their brains became insulin resistant.
So insulin is also very important for the brain. The brain is telling the body how to store the fat and how to store energy. And when insulin’s not able to get into the brain and have its action, then you start to not have the brain tell the body how to store this energy, and it ends up storing it viscerally. It’s like this default.
The Impact of Late-Night Eating on Sleep and Cognitive Performance
STEVEN BARTLETT: You know, putting those two things together — the thing I’ve noticed that impacts my performance the most, as it relates to articulation, cognitive performance, my ability to think, is those two things coming together. You talked about sleep and diet. It’s when I eat late, it’s when I eat close to sleep. If I do that a couple of nights in a row, I feel like my brain no longer works.
DR. RHONDA PATRICK: Yes. Obviously we all have to live our lives. There are social things, and it’s fun to go out and have a dinner with your friends or an event. But it’s not a good idea to eat a big meal fewer than three hours before bed. So you want to stop eating three hours before bed. And three is really the magic number in multiple studies.
Because when you eat a meal, it is activating your sympathetic nervous system — that’s the fight-or-flight response. That’s not what you want active when you’re about to go to bed. When you’re activating the sympathetic nervous system right before you’re going to bed — let’s say you eat a meal within an hour of bedtime — you’re digesting all that, your sympathetic nervous system is active. And even if you’re sleeping, it’s not good sleep. It’s fragmented sleep, disrupted sleep. Because you need to be in that parasympathetic part of the nervous system. That dominance needs to be parasympathetic, which is the rest and restore. It’s called “rest and digest,” but I don’t like “digest” because actually digesting is what activates the sympathetic nervous system. So it’s like the recovery.
STEVEN BARTLETT: So should I stay up then for three hours? If I eat at midnight, should I stay up till 3am?
DR. RHONDA PATRICK: No, no, you should just go to bed. But don’t do it on a daily basis. The key is the habit. And so if you need to eat something before bed, you should do something that’s light. Maybe a protein shake with some almond milk. Something that’s not super heavy.
STEVEN BARTLETT: I’ve heard you talk about fiber, resistant
DR. RHONDA PATRICK: starch — it does interestingly seem to help improve sleep. So maybe some rice or a potato. A little bit of rice or a potato.
STEVEN BARTLETT: Fries or something.
DR. RHONDA PATRICK: Maybe not a fried potato — a baked potato. And then cool it, because then it’s resistant starch, which is good for your gut microbiome.
STEVEN BARTLETT: Why?
DR. RHONDA PATRICK: It changes the composition of the fiber. And you can cook it, let it cool, and then heat it again — if you like to eat it heated — as long as it went through a cooling part, and then you can eat it. But that’s resistant starch. Resistant starch is also in green bananas, and is very beneficial for the gut and also, interestingly, for improving sleep.
Key Drivers of Visceral Fat Gain — and How to Lose It
So the things that are really moving the needle to make you gain visceral fat are basically being in a caloric excess, especially from refined high-fat, high-sugar foods, and then not getting enough sleep. Chronic stress is an amplifier of it. So if you’re constantly having cortisol, that’s kind of stopping the body from storing energy the right way, and it’s going viscerally as well. That amplifies, especially in the context of being in a caloric excess and not exercising.
Alcohol is another one. If you’re excessively consuming alcohol, a lot of the energy that you’re also consuming is going to be stored viscerally. I mean, you’ve seen the beer belly, right? That’s a thing. It’s visceral fat — it’s not beer, it’s visceral fat.
So alcohol’s another one. In terms of losing visceral fat, the good news is that you can lose it quite easily and quite rapidly.
STEVEN BARTLETT: I was going to say parents have a hard time, because you were naming those things about sleep and stress. And I was thinking, gosh, parents have it from all sides.
DR. RHONDA PATRICK: They do. But see, this is where the good news comes in. Part of the reason why sleep loss is causing you to gain visceral fat is because it’s causing your body to become insulin resistant. It’s like this vicious cycle — visceral fat causes insulin resistance, insulin resistance causes more visceral fat. And that’s why once you get into that cycle, it just spirals out of control, and you start to gain more and more and more.
Understanding Insulin Resistance
STEVEN BARTLETT: Sorry — insulin resistance. What is that? Is that when your body no longer produces insulin, or…
DR. RHONDA PATRICK: No, no. Insulin resistance is when your body is no longer responding to insulin. So it’s like you’re waiting for the phone to ring, and it’s ringing, but you can’t hear it. You’re not getting the signal. And so your cells are not responding to the insulin that’s made. Insulin is really helping your body move the glucose out — move it out of your bloodstream, where it can cause a lot of damage if it sits around.
STEVEN BARTLETT: And if you put too much pressure on the insulin system, then it kind of shuts down.
DR. RHONDA PATRICK: Eventually shuts down.
STEVEN BARTLETT: And the thing that puts too much pressure is consuming too much glucose, or…
DR. RHONDA PATRICK: Too much glucose. Refined glucose can do that. Visceral fat is one of the bigger causes of insulin resistance — it’s actually one of the major, major causes. Because if you are physically active and eating a lot of glucose, that glucose is going to your muscles. Physical activity makes your muscles very responsive to glucose without needing insulin. The transporters that transport glucose are super, super responsive when you exercise.
That’s why physical activity — and this is what I was getting at with parents — is so important. The visceral fat is the really big concern with insulin resistance. And this is the thing that people don’t even know about. A lot of people are thinking about glucose and, “Oh, I’ve got to watch my glucose.” And that’s all fine — yes, to some degree that’s also playing a role. But it’s the visceral fat that’s the real underlying problem that’s causing you to become insulin resistant.
You mentioned parents have it bad because they’re stressed out and they don’t get sleep. I was wearing a continuous glucose monitor when I became a new mother. I was appalled by my fasting blood glucose and by my postprandial blood glucose levels.
STEVEN BARTLETT: Never heard “postprandial.”
DR. RHONDA PATRICK: Postprandial means after a meal.
STEVEN BARTLETT: Okay.
DR. RHONDA PATRICK: So your levels go obviously much higher after you eat a meal versus in the morning when you haven’t had anything to eat. And my levels were so high — it was pre-diabetic — and I just couldn’t believe it. It’s not like I’m drinking Cokes and eating terribly. But there was a period of time when I’m not as physically active, particularly in the first couple of months. That’s really the time when you’re kind of just in this cave.
I immediately was looking into the scientific literature and found that high-intensity interval training and exercise can help almost negate most of those poor effects of causing insulin resistance and causing your glucose regulation to not be normal. That’s the good news for parents — new parents should prioritize exercise. And exercise does cause you to lose visceral fat. It’s not just any type of exercise — it really has to be aerobic, and the more vigorous the better.
Aerobic Exercise and Visceral Fat Loss
STEVEN BARTLETT: So for people that don’t know what that means — aerobic and vigorous.
DR. RHONDA PATRICK: Yeah. So what I mean is resistance training and lifting weights don’t really move the needle in terms of helping you lose visceral fat. It does help you improve your metabolism. It does help with glucose sensitivity and all that, because your muscles are going to be more sensitive to take the glucose in. But if you want to lose visceral fat, you’re going to have to do running, jogging, cycling, swimming. You want to get your heart rate up a little more.
STEVEN BARTLETT: Why?
DR. RHONDA PATRICK: It’s energy expenditure. It plays a role in getting you to a more caloric deficit. And that’s better. So that’s one way.
And the other thing is any weight loss program — so intermittent fasting, caloric restriction, GLP-1 receptor agonists and all the classes of GLP-1 — anything that is going to make you lose weight, lose fat, visceral fat is one of the first to go. And in fact, people on these weight loss programs, or even on an exercise training program, visceral fat is the first fat to go. And so you can lose it quite quickly.
Intermittent Fasting, Ketosis, and Visceral Fat
STEVEN BARTLETT: So on this point of fasting — are you a fan of fasting to combat visceral fat? And also, could you give me your thoughts on being in a ketogenic state as it relates to visceral fat?
DR. RHONDA PATRICK: Yeah. People, when they think about intermittent fasting, they kind of think about one thing, and they think about weight loss. But there’s a lot going on here. And I like that you mentioned being in a ketogenic state, because there’s also a metabolic switch that happens — this metabolic switch from burning carbohydrates and glucose to burning fatty acids and getting into ketosis. That’s a metabolic switch. And it’s very important.
There are two different things happening here. But intermittent fasting is essentially a good tool that people can use to reduce their calorie intake without having to count their calories. That’s why I like it. You can lose weight by counting your calories and reducing your calorie intake — I personally think that’s a lot of work. Some people love doing it, and that’s great. I think whatever works for a person.
But the way in which intermittent fasting helps people lose visceral fat is by reducing calorie intake. It’s like a tool that some people like to use. I like it because I can not think about it — I’ll skip one meal, making sure I get enough nutrients and protein in the meals that I eat, but I’ll skip a meal and it gets me in a caloric deficit without having to think about and count everything. So it’s easier on me to fast versus counting calories.
STEVEN BARTLETT: And how do you do that?
The Metabolic Switch: Fasting, Ketosis, and Fat Burning
DR. RHONDA PATRICK: So I like to fast in the morning, and the reason I like to fast in the morning is for the exact reason you mentioned, and that is the ketosis, which I like to call the metabolic switch. You’re not eating while you’re sleeping, obviously. So if you’re sleeping for eight, if you’re in bed for nine hours, 10 hours, you’re not eating during that time. And it takes about 10 to 12 hours for your liver to deplete glycogen. Glucose that’s been taken up by the liver is stored as glycogen so that you can then use it for energy later if you don’t have energy coming in.
STEVEN BARTLETT: So the glycogen is like the petrol station.
DR. RHONDA PATRICK: Yes.
STEVEN BARTLETT: So it runs out of petrol.
DR. RHONDA PATRICK: That’s right. It switches to diesel. And so after that switch, that metabolic switch, when you deplete that glycogen while you’re sleeping or while you’re not eating, after about 12 hours. And by the way, this is all relative because it depends on the kind of foods you eat and how physically active you are. So if you eat a lot of high carbohydrate, refined sugar stuff, you might take even longer to deplete your glycogen because you’re putting a lot of input in there. You keep filling up the fuel tank. But if you’re eating things that are more low carb, you might deplete your glycogen sooner.
So when you deplete your glycogen, you get into this metabolic switch because your body still needs energy, but there’s no glucose around. So you start to switch — your fatty acids are mobilized, they come out of your adipose tissue. This is why people lose fat. They come out of the visceral fat. You start to use those fatty acids and burn them as energy. And as a product of that energy, you’re making ketones — ketosis.
And the reason I like to do this in the morning is because then I can really get into that ketotic state. I fast for about 16 hours a day and then I eat my meals within eight hours a day. Typically, that’s what I do.
The reason I like to be in that metabolic switch state is many reasons, actually. One, the ketones themselves are providing my brain with energy — very easily utilizable energy — but they’re also acting as a signaling molecule to my brain going, “Hey, this is a stressful time. There’s no food. You better be cognitively sharp. You’ve got to find that food. You’ve got to know what you’re doing.” It’s an evolutionary adaptation. Humans for thousands of years were going through this metabolic switch because we didn’t have Instacart, we didn’t have Postmates, we didn’t have Uber Eats. We had to find our food, we had to hunt our food. And we didn’t always do that.
And so when I get into that metabolic switch state, I feel it. I feel more cognitively sharp and I feel less anxious, which is part of it, because those ketones also help increase something called GABA — that’s an inhibitory neurotransmitter. It essentially helps you feel calmer. When I feel calmer, I’m more cognitively focused because it’s like the background anxiety is down. You can focus. And so I love being in that state in the morning because that’s when I get my work done.
I also like to be in that metabolic switch state — and this is why I like fasting — in addition to the fewer calories I’m consuming. Your body has to be in that fasted state to repair. If you’re constantly in a fed state, fed states are important for anabolic growth — we need it to grow. But the repair state is also very important because with the growth comes damage, and you want to repair that damage because damage will accelerate aging.
So I like to give my body enough time. I don’t want to just wake up and eat where it’s like, “Oh, I’ve only barely depleted my liver glycogen. I’m not even in that repair state very long.” I want to extend it a little bit. And so I like to have that repair process active. It is active during fasting — fasting activates it. But you also have some amount of active repair going on even when you’re in a fed state. It’s just heightened when you’re fasted.
So those are the reasons I like intermittent fasting. I feel good when I do it. I also do a lot of training fasted. Cardiovascular, aerobic, endurance exercise — running, biking, that stuff — I like to do fasted. I’m not going for a ten mile run, I’m going for a three mile run. If I was going for a 10 mile run, I wouldn’t be fasted, I would need some fuel. But there are multiple studies showing that if you do aerobic endurance training — this kind of running, cycling, swimming type of training — you actually have better adaptations if you’re fasted versus fed.
STEVEN BARTLETT: What does that mean?
Fasted Exercise and Mitochondrial Adaptations
DR. RHONDA PATRICK: So much of the benefit from exercise — aerobic exercise, when you’re breathing hard, you’re working hard — is from the working hard. But your body responds to that because the working hard is causing inflammation, it’s causing oxidative damage. And your body is responding to that by going, “Oh, we’ve got to get better at this stuff.” So you have anti-inflammatory pathways activated, you have antioxidant pathways activated. Your body needs to burn fat, you need fuel. And so if you’re fasted, you get better at burning the fat and oxidizing the fat. And you continue to do that throughout the day better as well.
So you have what are called mitochondrial adaptations that are better. You make more mitochondria. Mitochondria are very important, little tiny organelles inside of most of our cells that make energy. They’re very important for everything — they’re running our brains right now so we can talk, our heart so we can breathe, our lungs, everything. And exercise does make you increase the amount of new mitochondria that you make that are young and healthy. If you’re fasted, it’s even better.
STEVEN BARTLETT: This has been a big debate around whether this applies to both men and women. Should both men and women exercise fasted?
Should Women Exercise Fasted?
DR. RHONDA PATRICK: This is my read of the literature and my thoughts on this, from also having spoken with experts that have studied male versus female responses to exercise. First and foremost, how do you feel when you exercise fasted? If you feel terrible, that’s a sign. I think listening to your body is the most important thing that you can do. There are times when I have to eat before I exercise and I listen to my body — that’s it, I’m going to eat.
When it comes to women versus men and doing exercise fasted, it also depends on — are you doing a 30 minute run? Are you doing a two hour run? If you’re doing a two hour run, you need to fuel. That’s a big stress. When it comes to a 30 minute run, you don’t really necessarily need to.
Now the problem with women is that if you’re in too much of a caloric deficit and you don’t eat enough food afterwards — you’re not refueling enough — and you’re doing very long, high volume types of exercise, then you can basically disrupt some of your hormones, your follicle stimulating hormone, luteinizing hormone. These things will make you become amenorrheic. So you basically stop ovulating and you stop getting your menstrual period.
STEVEN BARTLETT: And what’s the evolutionary reason for that? What’s going on?
DR. RHONDA PATRICK: Because your body is like, “There’s not enough food and energy around to sustain a growing fetus.”
STEVEN BARTLETT: So it’s shutting down.
DR. RHONDA PATRICK: So it’s basically like, “Hey, we’re not going to allow you to have a baby.” So you stop ovulating. You’re not making those eggs.
STEVEN BARTLETT: Is this often the case with women who exercise a lot and no longer have their menstrual cycle?
DR. RHONDA PATRICK: First of all, this is not a common thing. This is something that happens in elite athlete women that are not eating enough food. I did this to myself when I was in my early 20s and I was running — I was racing marathons and I was running 10 miles a day, eight to 10 miles a day, five days a week. And then I was eating carrots and hummus, and I just wasn’t fueling myself. I did this to myself too.
So how do you feel if you train fasted? Do you feel terrible? Don’t do it. If you want to train somewhat fasted, go for the protein shake with a little bit of almond milk or something like that, where you’re not eating a full meal, but you’re getting something.
So I do a lot of my training fasted and that has helped me. I’m 47 years old and perimenopause.
STEVEN BARTLETT: You’re in phenomenal shape.
DR. RHONDA PATRICK: Thank you, thank you. But I did notice, of course, as I started to reach that perimenopause part of my life, that I had to be a little bit more aggressive and put a little bit more effort in to not get this fat right here on my belly. Because it started coming up and that wasn’t an option for me.
Perimenopause, Visceral Fat, and the SWAN Study
STEVEN BARTLETT: Speaking of studies done for women, I’ve heard you talk in the past about the SWAN study, which kind of relates to what you just said there, relating to women in visceral fat. And they found that women experience an accelerated increase in visceral fat starting two years before their final menstrual period.
DR. RHONDA PATRICK: Yeah. Because that’s when their estrogen is plummeting. You’re just going off a cliff because you’re about to go into menopause.
STEVEN BARTLETT: What age would that be?
DR. RHONDA PATRICK: Average age of menopause is between 50 and 52 for women. There are a lot of things that can affect your reproductive lifespan, your ovarian aging. And unfortunately, one of them is the age you were when you got your menstrual period. So the younger you were, the younger you’re going to be when you experience menopause. Also, when your mother experienced menopause is very, very indicative of when you’re going to experience it.
But lifestyle and diet play a role too. Obesity accelerates ovarian aging, so you’re more likely to go into menopause earlier with obesity. Also, these chemicals that we’re exposed to — and we can talk about those as well — a lot of these endocrine disrupting chemicals affect the age of menopause as well and accelerate that. So in some cases, women go into menopause two years earlier than they would have otherwise.
STEVEN BARTLETT: And also you’re 47.
DR. RHONDA PATRICK: And a half.
STEVEN BARTLETT: And a half. And the data that I’m looking at here says when we think about perimenopause, it usually starts in the mid-40s, which is the age range you’re in. This is where the 8 to 10% annual visceral fat increase begins.
DR. RHONDA PATRICK: It is. And I can tell you from people in my life that I’ve seen going through this, it’s pretty sudden. You’ll see someone in your life that’s a woman going through perimenopause and maybe hasn’t had any other symptoms yet, so they haven’t really sought out any treatment. Now you can try to do some hormone replacement therapy as well to help with that. But they start to gain visceral fat and it shows up around the belly quite rapidly.
I noticed this in myself. It almost feels overnight. Seriously, this is the only symptom that I noticed in myself where it was like, all of a sudden my belly was growing — not super, super large, but enough where I was like, “There’s something wrong.” It’s not even necessarily reflected if you get hormone tests, because mine all seemed normal.
The thing is, estrogen, when it drops — that estrogen is so important for telling your body to store energy differently, not around the organs, but around other parts of your body, like your thighs and your butt, your adipose tissue. And so when that estrogen goes down and declines, it’s like, boom, it starts to go right to the belly.
So that is why, for me, intermittent fasting has been really important. Like with any weight loss or calorie restriction protocol, you do need to make sure you’re getting enough protein, because that’s important for muscle growth and preventing atrophy of your muscle. And you need to also do resistance training. That is a very important signal for muscle. Because the problem is some people calorie restrict and eat fewer meals, and then they’re not getting enough protein and they’re not training, and they start to lose muscle in addition to fat. And you don’t want to do that. You want to just lose the visceral fat and keep the muscle. Ideally, keep gaining muscle.
The Testosterone Crisis and Endocrine Disruptors
STEVEN BARTLETT: And for men, I was reading that testosterone and growth hormone typically peak in their late 20s. So I guess mine’s peaked already. Starting at age 30, testosterone drops roughly 1% a year. So between the age of 25 and 65, men typically see a 200% increase in their visceral fat, even if their total weight stays the same. So is that linked to the testosterone decline? Is that what’s going on there? What’s causing it?
DR. RHONDA PATRICK: Yeah, testosterone does help you burn fat. Even if you’re gaining visceral fat, it helps you burn it. It’s also why some women that are in perimenopause want to do testosterone, because it helps them burn the visceral fat. So it is linked to testosterone decline as well. But also, as men are aging, they become more sedentary. They tend to eat a little bit more, they’re consuming more calories. All these things are hand in hand. So it’s not just a one punch, right? It’s like multiple angles are kind of all compounding and coming together. Whereas you could get away with it a little bit easier when you’re younger because the testosterone is helping you burn it more. When you’re declining, it doesn’t work that same way. So even though you’re gaining it, you’re not burning it as quickly. So you start to have a net gain in it, if that makes sense.
STEVEN BARTLETT: So going back up to the top, then — we were talking about things you can do to lower your visceral fat. And we talked a little bit about exercise, sleep, diet. Is there anything else in that category?
DR. RHONDA PATRICK: Yeah, I think those are the main ones. Obviously avoiding excess alcohol consumption and also stress. Trying relaxation techniques to buffer that stress — that’s a big one. It’s an amplifier.
STEVEN BARTLETT: Yeah. People don’t talk enough about visceral fat. They look at other markers.
DR. RHONDA PATRICK: Well, most people just want to lose weight and look good. Or they look at HbA1c, your long-term glucose, or they’re looking at lipids. And visceral fat is just insidious. It just starts increasing, increasing, increasing. You can’t see it — until all of a sudden, belly. It’s bad, and it affects the way you feel daily.
Why Testosterone Levels Are Dropping
STEVEN BARTLETT: On this point of testosterone, why is it the case that testosterone seems to be dropping amongst men? I think it said something like — I wrote it down — testosterone levels in men have dropped by up to 20% over the last two decades, which is quite terrifying.
DR. RHONDA PATRICK: It is. So look, there’s a lot of factors that can affect testosterone. I mentioned dietary factors, refined sugar. Sleep is a big one — people aren’t getting enough sleep. Lack of sleep drops testosterone. Micronutrients — not getting enough zinc, for example. Zinc is very important for testosterone synthesis, and magnesium as well. There are important nutrient components.
But I think the big player here is actually environmental. I think that we are being bombarded with what are called endocrine disrupting chemicals. These are man-made chemicals. A lot of them are part of plastic — they’re made to help plastic be more durable or more robust, or they’re water resistant, oil resistant, fire resistant, flame retardant.
There are probably three main endocrine disrupting chemicals that are found in our environment, mainly because they’re in plastic or in things that are water resistant, oil resistant, or fire resistant. BPA — Bisphenol A — is one. Another one is phthalates. And the last one would be PFAS — these are the forever chemicals. These are the three main players, I would say, in terms of disrupting endocrine function. Endocrine being hormones — sex hormones like testosterone and estrogen, but also thyroid hormone, which is very important for regulating our metabolism.
STEVEN BARTLETT: They’re really causing a problem.
DR. RHONDA PATRICK: Absolutely.
STEVEN BARTLETT: Because I’m looking at the picture you have there of PFAS. And it’s got a coat and shoes on there. You’re telling me the clothes that I wear are having an impact on my hormones?
DR. RHONDA PATRICK: They can, but I think it’s less of a direct effect and more downstream. The PFAS chemicals, or the forever chemicals, are used in things to make them oil resistant, stain resistant, water resistant. So the Teflon pans would be the biggest example. You remember those nonstick pans? They have Teflon that has PFAS on it.
STEVEN BARTLETT: We’re going to go into my kitchen in a second. So I’ll take all of the viewers that are watching now into my kitchen. We’ll have a stroll around my kitchen. You let me know if there’s some things.
DR. RHONDA PATRICK: Oh gosh, I hope you don’t have Teflon. But my mom used it when I was growing up. I remember the nonstick pans. That stuff is coming off into your food. And so you’re eating these PFAS.
STEVEN BARTLETT: How do we know that they’re dangerous?
BPA, Phthalates, and Their Effects on Hormones
DR. RHONDA PATRICK: Okay, well, I’ll tell you how we know. Let’s start with the PFAS chemicals — they’re really more affecting the thyroid, and they’re affecting ovarian aging. They seem to target the ovaries and accelerate the age that you’re going to get menopause. So you’re going to get it around one to two years earlier if you have a high amount of these forever chemicals.
But there have been a lot of studies looking at BPA — Bisphenol A. That’s a big one. Because you see a lot of marketing around “BPA free.” “This plastic water bottle is BPA free.” Well, it’s BPA free, but it has another chemical called BPS, which is very similar, if not worse than BPA.
BPA is something that is found in a lot of water bottles. It’s in those plastic water bottles. It lines the cups of paper cups — like those to-go coffee cups that you’re getting at your favorite coffee place. Plastic is lining them, because it’s protecting it from the liquid. BPA has been linked to many different diseases, but really, it’s an endocrine disruptor.
So what it does is a couple of things. One, BPA acts as an estrogen mimetic — it kind of mimics estrogen and it binds to the receptors that estrogen uses to do its function. And so it sometimes binds to estrogen receptors and either makes it seem like there’s estrogen around, or it blocks estrogen from working. It depends on the dose and the concentration — so it can do both. But it also binds to androgen receptors that interact with testosterone.
There have been studies that found that men with high amounts of BPA also have low amounts of testosterone. But there was also a study done in teens — this is when your sexual development is happening, and testosterone is very important during puberty. Adolescent boys that had the highest amount of BPA had 50% lower testosterone than the boys that had the lowest amount of BPA.
The biggest one affecting testosterone is the phthalates. Phthalates are present in a lot of PVC piping and in a lot of our food packaging. All those thin plastic wrappings — you go to the grocery store and you get a filet mignon steak, and it’s wrapped in plastic. All that plastic wrapping around the foods that we’re eating has phthalates in them. They make the plastic more flexible. Phthalates are also found in our hair products, our cosmetic products, our creams. And they’re also very lipid soluble — they like fat. They are drawn to fat. So when you have plastic around fat — like cheese, meat — it’s getting into that meat, it’s getting into that cheese.
The phthalates disrupt our hormones in ways similar to BPA. They’re binding to the androgen receptor, but they’re also going into the testes and disrupting the synthesis of testosterone. There was a study in men that had the highest phthalate levels — those men had 20% lower testosterone compared to men with lower levels.
And it’s affecting not only just the testosterone, but it’s affecting sperm quality. The shape of the sperm wasn’t good. It’s affecting the number — sperm count is down if they have higher BPA or higher phthalates — and also motility, the ability to swim.
The Impact on Fetal Development
DR. RHONDA PATRICK: Pregnant women that get exposed to high levels of phthalates, if they’re carrying a male fetus — if they’re having a boy — what’s been shown is it’s also affecting sexual development. These boys are getting something called hypospadias, where the slit on the penis is moved backwards, kind of closer to what a woman would have. And they’re getting undescended testicles — one of their testicles is not descending. That’s associated with infertility and testicular cancer, which is the big one.
This is happening at an alarming rate. Something like 20% of boys now have an undescended testicle.
STEVEN BARTLETT: It’s crazy, because their mother had high phthalates.
DR. RHONDA PATRICK: This is definitely something that is known in our environment to cause that. I don’t know if that’s the only cause, but in my opinion, it is a very, very concerning cause that nobody is talking about and that should be addressed. And it’s everywhere. We have these in all of our plastic wrappers — everything that we’re eating. You get your meat, you think it’s fine, but it’s wrapped in plastic and those phthalates are getting into the food. So they’re getting into our bodies. They’re disrupting hormones, they’re disrupting sexual development, they’re disrupting our ovaries, estrogen, ovarian aging, age of menopause. They’re disrupting thyroids, the thyroid hormones.
There are even studies now with pregnant women that have high levels of BPA — they are six times more likely to have a child with autism spectrum disorder compared to women with low levels of BPA. Again, BPA is disrupting the estrogen and androgen receptor. And this is very important because the androgen — you want to have it — it’s also disrupting aromatase, that enzyme involved in converting testosterone into estrogen.
Believe it or not, when you’re a boy developing in your mom’s womb, estrogen plays a very important role in brain development and in what’s called masculinizing the male brain. It’s kind of contradictory — you’d think, “Oh, well, wouldn’t testosterone do that?” Well, actually, estrogen is very important for masculinizing parts of the male brain. And so when you have aromatase being inhibited by Bisphenol A — by this endocrine disrupting chemical that is so ubiquitous everywhere —
STEVEN BARTLETT: — that is found in plastic bottles.
DR. RHONDA PATRICK: Plastic bottles. It’s found everywhere.
How to Reduce Your Exposure
STEVEN BARTLETT: So what do you recommend?
DR. RHONDA PATRICK: First of all, if you can eliminate or not drink out of plastic bottles as much as possible. If you do want to go get coffee, either drink it there in their mugs or bring your own to-go mug. I have a Yeti kind of to-go coffee mug that I’ll bring into a Starbucks or Coffee Bean, and I’ll have them fill it up.
Soup cans — canned soup — are lined with BPA, they’re lined with plastic. And soup usually goes into the can hot, as part of the sterile technique. Multiple studies have classically shown that canned soup can increase BPA levels by a thousand percent — crazy amounts. So don’t eat canned soup as much as possible.
Obviously, this is about the habit, not the one-off. But try to avoid cans. Even drinking out of soda cans, even your favorite sparkling water cans — don’t make it a daily habit, because they are lined with plastic. That’s a source of BPA into your bodies.
There are ways that you can excrete BPA. The major way to get rid of it is through urine — it’s excreted through your urine, but it has to become water soluble first. It’s a fat-soluble compound. And so there are things that we can eat in our diet that will increase that excretion. Compounds in broccoli — broccoli sprouts being the big one. Sulforaphane activates a pathway with enzymes involved in making BPA become water soluble so it comes out in your urine.
STEVEN BARTLETT: Oh, so broccoli’s like a cleanser?
DR. RHONDA PATRICK: It’s like a cleanser. We actually do have what’s called phase two detoxification enzymes. In our body, we have the ability to detox a lot of things. We just have to give our body the right input so that it can activate those pathways.
I personally take a supplement of sulforaphane because I want a concentrated amount of it. I used to do broccoli sprouts — broccoli sprouts have 100 times more sulforaphane than mature broccoli — but you have to sprout them, and then there are contamination issues. Some people do it and it’s great, but I used to do it and I don’t anymore. I just take a supplement.
STEVEN BARTLETT: That supplement’s called —
Toxins in Your Kitchen: A Walkthrough with Dr. Rhonda Patrick
DR. RHONDA PATRICK: The supplement I take is called Avmacol. It’s by a company called Nutrimax. I’m not affiliated with them. I like their supplement because, one, they’ve got 12 published studies using it — clinical studies too — showing that it actually helps with autism. Children and adolescents with autism that take the sulforaphane supplement have improved symptoms because it’s a detox. It helps.
Interestingly, people with autism are about 30 times less likely to excrete BPA. It’s a weird thing going on here where BPA increases autism spectrum disorder, but then kids that have it are not able to detoxify it as well. Again, I think that excretion is important, but avoiding the plastic as much as you can — make it a habit. Don’t freak out. I mean, obviously you can make yourself crazy, and stress is not good, as we talked about. I see you going, “Oh, my God.”
STEVEN BARTLETT: Yeah. No, I’m thinking about just how casual I am about these things. And I could easily make small changes. Frankly, I could easily make big changes in the position I’m in. I could just say, in my company, we no longer buy this kind of stuff. I could say in my kitchen — to my team or whatever — “Let’s not buy this.” Can we go look at my kitchen now?
DR. RHONDA PATRICK: Let’s do it.
STEVEN BARTLETT: Okay, let’s go to my kitchen. So we’re going to go to my kitchen. If you’re listening on the dog walk, this might be a nice time to sit on a bench and look, because you’re about to go into my kitchen, and we’re going to look at real things that you might not even know in your kitchen are causing you some of these problems. Come with me.
Black Plastic: The Hidden Danger in Your Takeaway Containers
Okay, so the team have been here for the last couple of days. We’ve been getting lots of takeaways. And so this is a higgledy-piggledy of everybody’s food. What’s wrong?
DR. RHONDA PATRICK: You’re pulling black plastic.
STEVEN BARTLETT: What’s wrong with the black plastic?
DR. RHONDA PATRICK: We talked about plastic — it has BPA, it has phthalates — but it also typically is made from recycled electronics. And the problem here, Steven, is recycled electronics have flame retardants in them because you don’t want your electronics catching fire. There have been a variety of studies now that have found that black plastic has a high amount of these flame retardants that are leaching into the food and getting into people’s bodies that way. Not only do you not want to eat out of black plastic, you don’t want hot food going in there, because that’s the worst.
STEVEN BARTLETT: Can I get a bin bag? I need a bin bag. Okay, so let’s throw that in the bin. What else? I’m going to take all of it out.
DR. RHONDA PATRICK: Okay. This is the other thing that really stands out to me — because spicy foods, anything acidic that goes into plastic, causes the chemicals to leach into it even more rapidly, kind of the same way the heat does. So heat and acidic foods — not good in plastic.
STEVEN BARTLETT: So my spicy sauce, if it comes in a little plastic tub, it’s going to leach in.
DR. RHONDA PATRICK: Look, if it’s the one-off, okay, but not as a habit. Yes, a big-time leach in. You’re eating BPA hot sauce.
STEVEN BARTLETT: Okay, so the black stuff is out.
DR. RHONDA PATRICK: It’s going in hot. Yeah. This has phthalates and BPA. I mean, look, are you drinking this every day or is it the one-off?
STEVEN BARTLETT: No comment. No comment. Mind your bit, sir. Okay, what else? What about this? This is made of paper.
DR. RHONDA PATRICK: Here’s my little thing — do you see that waxy coating? Is it waxy?
STEVEN BARTLETT: A PFAS on the edge.
DR. RHONDA PATRICK: Yeah. Does it seem like it has a waxy substance to you?
STEVEN BARTLETT: Yes.
DR. RHONDA PATRICK: This is better than the black plastic. If there are like tears — this is better than black plastic.
STEVEN BARTLETT: Okay. And this?
DR. RHONDA PATRICK: Ding, ding, ding. This is great. This is the best thing that you can do. If you’re going to have food made for you or you want to order takeout, have someone make it for you and deliver it in this.
STEVEN BARTLETT: And this is a bamboo lid.
DR. RHONDA PATRICK: Bamboo lid with Pyrex glass. Right.
STEVEN BARTLETT: Okay, so this is good.
DR. RHONDA PATRICK: This is great.
STEVEN BARTLETT: So I need more of this.
DR. RHONDA PATRICK: You need more of this. And get rid of all — I mean, this is already looking better.
Microplastics and Nanoplastics: What’s Really in Your Water
DR. RHONDA PATRICK: This is on the scale — at least it goes in cold. So here’s the thing: microplastics are also shedding into this. We didn’t talk about microplastics. They’re shedding into here. The chemicals, not as much in something like this, but they’re still getting in. So this is a little bit better when it comes to the tears here — the hot food is the worst. This is a little bit better. But I still would get glass.
STEVEN BARTLETT: Because it’s cold.
DR. RHONDA PATRICK: Because it’s cold.
STEVEN BARTLETT: So it’s not seeping.
DR. RHONDA PATRICK: Exactly.
STEVEN BARTLETT: Okay, so I might be able to keep that then. What else do you notice here?
DR. RHONDA PATRICK: So I noticed that I really like your glass sparkling waters. That’s great. Because glass is less likely to have microplastic shedding, less likely to have the chemicals. There was a study that actually found, interestingly, there were more microplastics on the top. The paint that’s on these lids — plastic polymers are used in that — and during the processing and bottling of these things, they get into the water. So believe it or not, glass bottled water has more microplastics than plastic bottled water.
Okay, this is terrible, but I’m going to tell you why I think plastic is still worse. This has microplastics, but it also has BPA and phthalates. They’re in this water. This was not always cold — it was in some warehouse, some shipping container. Who knows how it got here? It’s been heated up several times, I’m sure.
The problem is that there was a study showing that glass bottles have a higher amount of microplastics than plastic. And you might ask, “Why is that?” Because they’re all coming off this paint and getting in. When it comes to microplastics, size matters. I’m not as worried about it having more microplastics because it would show that they were large microplastics. Your body doesn’t absorb large ones very well — they come out through your feces. Plastic bottles have tons of what are called nanoplastics — very, very small particles that get into the gut and get into your bloodstream. So I still go for the glass water. I would avoid drinking out of these as much as possible.
Condiments, Cheese, and Hidden Plastic Exposure
DR. RHONDA PATRICK: So I like how you have these condiments in glass. This is how my refrigerator looks as well. I’m very, very obsessive about anything that has acidity in it, like hot sauce and ketchup — it needs to be in glass, because the acidity is leaching microplastics and BPA and phthalate chemicals into your condiments. And then you’re putting that on your food and eating them. Again, this is ubiquitous. It’s everywhere. Plastic is everywhere, the chemicals are everywhere. And you’re not even thinking about the fact that your hot sauce and ketchup are also vehicles for delivering these microplastics and their associated chemicals into your body.
So I really like these. This one, I would go for a glass mustard — those are better glass bottles. So this is plastic. Same thing — it’s acidic. I would say, for the most part, the butter — oh yeah, this is bad. Is this butter or cheese? Yeah. So this is a problem also. If you look at this, it’s that flexible, plasticky stuff — it has phthalates in it.
STEVEN BARTLETT: Well, this, this—
DR. RHONDA PATRICK: Oh, that’s even worse. Yeah. So this is the plastic that — phthalates are in this, and they’re fat-soluble, and they’re just leaching into this fatty cheese. So you can buy cheese without this — just in a container — that’s a little bit better. I’m thinking of feta cheese, for example. Some feta cheese comes in this plastic wrapper, but you can buy it with just the container, and at least it’s not like close, seeping into it, getting the chemicals into it.
STEVEN BARTLETT: Ah, but this is fine, isn’t it? Eggs?
DR. RHONDA PATRICK: Yes, eggs are great.
STEVEN BARTLETT: There we go.
DR. RHONDA PATRICK: Eggs are great.
STEVEN BARTLETT: We found something.
Kitchen Utensils: Wood Over Plastic and Silicone
STEVEN BARTLETT: Okay, Rhonda, so spatulas and kitchen utensils — are these good? Are these bad? What’s the best?
DR. RHONDA PATRICK: Yeah, good question. These are great, right? There’s no plastic here, no possibility of plastic leaking into your foods. You’ve got your nice pasta spoon. These are silicone. In theory, the silicone should be okay. The problem is that a lot of silicone actually still has plastic mixed in with it. So I go for the wooden ones — like this wooden spatula. That’s what I use. You in theory should be good, but in practice, a lot of silicone that’s been measured and tested does have plastic. So I would say if you want to really be careful, I would switch.
STEVEN BARTLETT: But most people at home probably have a plastic spatula. Is that accurate?
DR. RHONDA PATRICK: Most people at home have a plastic spatula, and a lot of people also have black plastic spatulas — which, again, back to that: black recycled electronics, flame retardants. These are cancer-causing chemicals. Brominated chemicals that are causing cancer. So yeah, I would say that even shifting from the plastic to this is probably a step up. But I don’t know that this is just pure silicone. I would guess that there’s some plastic still in it. And so if you’re heating it up, the plastic is getting into your food.
Pans and Cookware: Avoiding Teflon and Non-Stick Coatings
STEVEN BARTLETT: Okay, what about my pans here?
DR. RHONDA PATRICK: All-Clad. This is what I use. These are amazing. No plastic lining, no PFAS, no non-stick. So most people’s pans at home have a sort of protective layer that’s non-stick so that they can cook their food and it doesn’t stick — like scrambled eggs. They’re kind of a pain in the butt if they stick. But everything that has the forever chemicals in them is being heated up and is leaching into your food and you’re eating it. So really what you want to avoid the most is Teflon — anything that’s non-stick.
STEVEN BARTLETT: It’s harder to cook with these though.
DR. RHONDA PATRICK: It’s so much harder. But you know what? You’re healthier, and that’s what you have to keep in mind.
STEVEN BARTLETT: The other thing I want to talk to you about is the blender.
The Blender Problem: Microplastics in Your Smoothie
DR. RHONDA PATRICK: Ah yes, the blender. This is one that people often miss. The problem is most blender tops — that’s blending your stuff — is plastic. And there are studies showing that when you have a lot of friction on plastic, that releases orders of magnitude more microplastics. And of course their associated chemicals are hitchhiking along there.
There are companies that make a stainless steel version of the blender. And I highly recommend, if you’re someone like myself — I like to do my kale blueberry smoothies — that you switch to the stainless steel. I did, I switched for my family. Because essentially the friction, you’re drinking microplastics and chemicals. So that’s bad.
Stop Touching Receipts!
STEVEN BARTLETT: A receipt?
DR. RHONDA PATRICK: Yeah. Don’t touch it.
STEVEN BARTLETT: What do you mean don’t touch it?
DR. RHONDA PATRICK: So receipts are — why are you touching it like that — covered with BPA? I mean, literally just covered. That’s how it prints it, right? This isn’t like a printer, this is printed. It’s a thermal paper. And the BPA is allowing the printing to happen, and so they’re covered with bisphenol A.
People that are handling receipts, like cashiers that are handling receipts, have really high levels of BPA, particularly if they use hand sanitizing lotion or any lotion, any sort of cream — it makes the BPA… Again, BPA is fat soluble. These creams, the hand sanitizers are carrying it inside your bloodstream about 100 fold higher than not having that.
So first of all, you can opt to have a receipt emailed to you. If you need the receipt, I would do that. Or, don’t touch it. But also, if you work in the cash, if you’re a cashier and you work in this industry, really, really, please wear nitrile gloves. I mean, this is like your BPA levels — if you were to go get them measured, which you can, there are companies out there now that do measure BPA levels in urine — you will see that they are extremely, extremely high.
Nitrile gloves will protect you from the BPA getting across your dermal barrier and getting to your bloodstream. Latex gloves do not. So make sure they’re nitrile gloves. And for people that are not in the industry, try to avoid the receipts. I mean, it’s a really big exposure to BPA that people aren’t even realizing.
STEVEN BARTLETT: I can tell by the way you’re grabbing the corner of it like it’s feces or something.
DR. RHONDA PATRICK: Oh, it’s terrible. And my son — kids love paper — and of course I don’t want them touching it because we talked about that study in adolescent boys where they had high BPA levels and that was associated with a 50% reduction in testosterone. I mean, this is at a part of your life when testosterone is important for sexual development and development in general.
So really, really, really important to remember: receipts are a very big source of BPA that people are not thinking about, particularly people that are routinely handling these receipts.
Water Filters: Are You Solving One Problem and Creating Another?
STEVEN BARTLETT: And the other thing I want to talk to you about is water. So here is one of my water filters. I also have a filter attached to the tap. What are your thoughts?
DR. RHONDA PATRICK: So this is filtering water, but it’s filtering it into plastic, and it’s also got a plastic filter. So I think that you’re probably filtering away some other things — pathogens, other chemicals that might be in the water — but you’re essentially reintroducing the plastic. So I don’t know that that’s necessarily the best way to get the filter.
What you have over here is a reverse osmosis water filter. That is absolutely the ideal. Reverse osmosis water filters filter out microplastics, nanoplastics, BPA, phthalates, chemicals — all these things that we’re talking about today. People can get a tabletop one, kind of like this is tabletop, but it’s a tabletop reverse osmosis water filter. These only filter out the bigger, larger plastic size, microplastic size.
And then the last thing I want to mention, Steven, because you do have a reverse osmosis water filter, is that it does filter out a lot of small particles, including essential trace elements and some essential minerals and stuff. So you want to make sure that you are taking a multivitamin mineral supplement, and you can also get what’s called little essential element drops that have things like phosphorus, manganese, iodine — some of these things that are being filtered out of your water — and making sure you’re reintroducing that to your water.
STEVEN BARTLETT: Ah, okay. So it takes some good stuff out, too.
DR. RHONDA PATRICK: It does, yeah.
Hidden Plastics in Your Kitchen
STEVEN BARTLETT: Okay. Is there anything else that maybe is either in my kitchen now or not in my kitchen that is a culprit of BPAs and PFOAs?
DR. RHONDA PATRICK: Yeah. Here’s the first problem here. And then inside where the hot water is going through, there are plastic pieces. So the hot water is going through plastic to get to your little espresso cup here. I actually looked into this because at first I thought they were lined with plastic — they’re not. My concern is mostly the water going through the system that’s heating up. It’s got plastic piping in there that it’s going through.
STEVEN BARTLETT: Okay. So I’m going to just stay there and I’m going to just grab. Okay. So this is now the coffee that I drink called Contir. They flash freeze it at the perfect moment and it’s delivered frozen. So metal. And then this is an aluminum lid.
DR. RHONDA PATRICK: Right. So it shouldn’t be lined with plastic. Right.
STEVEN BARTLETT: You go like this, press the little button on top and it goes straight into your glass. And then this comes out and that’s the coffee.
DR. RHONDA PATRICK: Oh, I love it.
STEVEN BARTLETT: So you just drop — it’s funny, because they’re a sponsor, so disclaimer. And I’m also an investor in this company. So no machines at all. Put it straight into the glass. Pour the hot water in. That’s it.
DR. RHONDA PATRICK: So it’s like — instead of instant, it’s like instant coffee, but it’s real coffee that’s been frozen.
STEVEN BARTLETT: It’s from some Stanford engineers who flash freeze it at the perfect moment to lock in the taste. And you can literally smell.
DR. RHONDA PATRICK: Smells good.
STEVEN BARTLETT: Smells good. Yeah.
DR. RHONDA PATRICK: Yeah. I’m so glad you’re not putting it in a machine. Because that’s —
STEVEN BARTLETT: No, no longer do that. Okay. So this is my supplement cupboard. It’s a mess, but I’ve pulled out things that I’m personally interested in. Good, bad, indifferent.
Glutathione: Are You Wasting Your Money?
DR. RHONDA PATRICK: The first one that jumped out at me when I was looking is reduced and active glutathione. This is something that I think people should be aware of — there’s marketing involved here. Glutathione is a major antioxidant. We make it in our body. We make it in our brain.
STEVEN BARTLETT: What does it do? Sorry.
DR. RHONDA PATRICK: So it’s a very important antioxidant. It helps negate oxidation, which is causing brain aging. It’s negating oxidation, which is aging yourself. People want to supplement with it because they’ve heard about glutathione and how beneficial it is and how it’s a great antioxidant.
The problem is, because our body makes it inside of our cells — inside of our cells — we don’t have a transporter to get glutathione from the outside of our cells. Like if we eat it, and if it makes it through our digestion, which it really doesn’t, into our cells. And so this kind of glutathione isn’t going to make it inside of your cells.
STEVEN BARTLETT: So this is just a waste of time.
DR. RHONDA PATRICK: It is. You’re going to want to get something called liposomal glutathione. Liposomal glutathione has been shown to get inside because liposomes — it’s essentially taking the glutathione molecule and encapsulating it in something that’s going to fuse with your cell. Liposomal products in general have a higher bioavailability for that reason.
STEVEN BARTLETT: So let me repeat that back to you so I’ve got it. If it’s liposomal, it’s basically in a packet which can get through into the cell. If it’s not — this one is reduced and active — then it’s never going to get in the cells. It’s a waste of time. It’s just going to be excreted.
DR. RHONDA PATRICK: Yeah, I would say that it’s really not doing much, and that if you’re going to supplement, liposomal glutathione is what I have.
Vitamin D: D2 vs D3 and Why It Matters
STEVEN BARTLETT: What about this vitamin D3? I’ve always been confused because people say take vitamin D, but then this one says D3.
DR. RHONDA PATRICK: Right. D3 is the form of vitamin D that you make when you’re in the sun. That’s the major way we make vitamin D — from sun exposure. There is a plant form of vitamin D called vitamin D2. It’s found in things like mushrooms, for example.
The problem is there have been studies showing that vitamin D2 — which is unfortunately what a lot of vegetarians take because they want a vegetarian form — is not as effective as vitamin D3. Vitamin D3 is also found in sheep skin because the sheep are making it in their skin when they’re exposed to sunlight.
If you are a vegetarian or a vegan, you’re going to want to look for vitamin D3 from lichen. Lichen is that green stuff that you can find on trees and stuff, that also makes vitamin D3. And so it’s a much better option than getting the vitamin D2, which is what a lot of vegetarians do.
There’s actually a recent study showing that people that are vitamin D deficient — so they’re not getting enough vitamin D3 because we don’t go out in the sun anymore — they have accelerated aging. And if they start supplementing — this is a very large study, by the way — they supplemented with vitamin D3 and they slowed their biological aging by almost two years. That didn’t happen in people that were not vitamin D deficient from the start.
So it’s not like a vitamin D3 supplement is going to do something miraculous if you already have enough vitamin D. The point is to avoid deficiency. And so, someone like yourself that probably doesn’t go outside a lot — but also when you go outside, you have darker skin. Melanin is a natural sunscreen. And so people with more melanin have to spend a lot more time in the sun. And so that is something to consider as well.
The Case for a Simple Daily Multivitamin
STEVEN BARTLETT: Well, I can always just take my multivitamin, right?
DR. RHONDA PATRICK: Multivitamin. I think I might have talked about one study last time we talked, last episode, where men and women that were older adults — they were 65 years and older — they took one Centrum Silver a day. And I’m not advocating for Centrum Silver, I’m just saying that was involved in this study. And after three years, they had reversed their brain aging, global brain aging, by 2.1 years, and they reversed their episodic brain aging by almost five years.
Episodic memory is the kind of memory involved in remembering events and people and things like that. As you get older, that stuff doesn’t come as quick. So it delayed that aging by five years.
The same study also just recently published — literally a couple of weeks ago — again, part of this large study, it’s called the COSMOS study, they looked at the multivitamin use and biological aging, epigenetic aging, and they found that the Centrum Silver multivitamin also slowed biological aging, epigenetic aging by a few months. And this was only after two years.
And you might go, “Oh, a few months,” but that was after two years. And that trial was two years long. So if you add two years and then you add another two years — and then you’re talking about 20, talking about 30, talking about 50 years — that is slowing aging the entire time. It adds up, it’s cumulative. And it’s one of the easiest things that someone can do to basically make sure that they’re aging better. There are things that are harder to do, but that to me is such low hanging fruit. It’s easy.
STEVEN BARTLETT: What is it about this — what is in here that’s making a multivitamin have such profound effects?
DR. RHONDA PATRICK: If you look at the back at the supplement facts, there’s a lot of vitamins and minerals — things like vitamin C, vitamin D3, vitamin E, vitamin K, niacin, the B vitamins, folate — you have things like selenium, these essential elements. These are all things that we need to run everything in our body: all of our metabolism, our neurotransmitter synthesis, our immune system, our liver. These are cofactors that are really important for all those things. And you don’t realize how important they are until time goes on and things start to fall apart.
It’s basically filling the gaps, because we’re supposed to get these things from our foods. We’re supposed to be getting all these vitamins and minerals from our foods, from our water, and it’s just not happening for many reasons.
One, our soils are depleted. The organophosphates, like glyphosate, are depleting our minerals. And so the foods that are being grown in the soil aren’t getting the minerals that they’re supposed to.
And then the second problem is we’re not eating the right foods because we’re eating takeout. We’re eating foods that are not micronutrient dense — things like dark leafy greens. We’re not eating the colors of the rainbow. And those are really important for vitamins and minerals.
Choosing the Right Supplements
STEVEN BARTLETT: So I’ve got two questions there. Is there a multivitamin that I could take that is not good for me? Because when I go to the shops, there’s so many different types these days, and I don’t know which one’s good, bad, or how to tell the difference. And so honestly, sometimes I just go based on the most expensive because I assume the most expensive is the best quality.
DR. RHONDA PATRICK: The problem with supplements is they’re not regulated. Not that I necessarily want them to be, but it is a problem because supplement companies can kind of put whatever they want in the supplements. They don’t necessarily have the amount of active ingredient that they say, or they can either have too little or too much.
For example, some vitamin D3 supplements and some melatonin supplements have, in some cases, 1,000 to 10,000 fold more. And it was a really big problem with melatonin, because melatonin is that hormone that you make to help you fall asleep, and there were excessive amounts in them. So it’s not regulated. So you really don’t know the amount you’re getting.
So I would say, number one, go to a trusted brand that does third party testing. There’s so much third party testing now. Consumer Lab does it. You can look up what they’ve tested. But for a man, I would say the thing that’s essential here is you don’t want to get iron. You don’t want supplemental iron.
STEVEN BARTLETT: Well, someone told me to start drinking these iron drinks.
DR. RHONDA PATRICK: Were you iron deficient?
STEVEN BARTLETT: No.
DR. RHONDA PATRICK: Okay.
STEVEN BARTLETT: I was just sick one time and they said this would really help. This wasn’t a scientist, it’s just a friend.
DR. RHONDA PATRICK: Most men do not need to supplement with iron unless they have a problem with iron and they’re anemic. Iron can be very bad. If you’re supplementing with iron, it’s very reactive and it causes oxidative stress easily. It’s called free iron. The free iron reacts with other things — with your DNA, your cells. And so most men do not need to supplement.
In fact, there’s even something called hemochromatosis, where you basically have too much iron already. And if you have those genes, which is actually quite common, then you’re really talking about iron overload. So you really do not need to supplement with iron.
Women — premenopausal women — are different, because premenopausal women do lose a lot of iron from menstruation. So about 16% of menstruating women are iron deficient. And then if you add exercise on top of that — a lot of endurance exercise — you can get lysis of your red blood cells. And so you do need iron for your red blood cells. If you’re eating meat, if you’re not a vegetarian, maybe that would be a case. If you’re a vegan or something, maybe some iron could come in. But you have to get your iron levels measured. You don’t want to be too high because it does cause damage.
I would say that premenopausal women, iron is especially good around your cycle. Postmenopausal women, once you hit menopause, you kind of shift to like what a man needs. You don’t need the iron again. So it’s very much just premenopausal women that need iron.
Omega-3 Fish Oil: One of the Best Things You Can Do
STEVEN BARTLETT: That’s so funny. I’ve been drinking these omega-3s — does that help?
DR. RHONDA PATRICK: Yes, omega-3 fish oil, as we’ve talked about before. This is probably one of the best and easiest things that people can do to improve their health and improve the way they age. Omega-3 fatty acids — 90% of the US population is not getting enough of them. 80% globally. Everyone, nobody’s getting enough omega-3 fatty acids, particularly from seafood.
The EPA and DHA from fish oil are probably the best forms. We talked about studies — if you have a high omega-3 index, you have a five year increased life expectancy compared to a low omega-3 index. If you’re a smoker and you have a high omega-3 index, then you’re going to live as long as a non-smoker with a low omega-3 index. So the low omega-3 index is like smoking, basically. You have a 66% lower chance of getting Alzheimer’s disease with a high omega-3 index.
And even more recently, there were studies showing that omega-3 slows epigenetic aging. There was a study out of Switzerland where these individuals were mostly active — 88% of them were already physically active at the start of the trial. The trial involved omega-3, vitamin D, and resistance training, or the combination of all three. And only the omega-3 was able to slow epigenetic aging — biological aging — because they were already physically active, so adding resistance training on top of their baseline didn’t do much, and they were vitamin D sufficient.
The combination of all three slowed epigenetic aging by four months, just after one year. And if you imagine that, it doesn’t sound like a lot, but it’s compounding. Within that study, they also looked at real world outcomes — they had a 60% less likely chance of being pre-frail, and they were also less likely to get cancer. So it’s really translating to these health outcomes that we think of.
All you need to do is supplement with about 1.6 to 2 grams a day of omega-3 to get a good omega-3 index. But I will mention one thing, Steven — keeping it at room temperature, I don’t think that’s a great idea. Because fish oil is a polyunsaturated fatty acid, it is prone to oxidation. So you want to put it in a low temperature environment.
I keep all my fish oil frozen. And then when I’m ready to use it, I put it in the fridge. So I have a stock of it, I buy it, and then it’s in the freezer. And then I put the bottle I’m using from in the fridge. Freezing it does nothing to it — it’s fine. So it’s basically just keeping it at really, really low oxidation.
STEVEN BARTLETT: So I need to put this in the fridge.
DR. RHONDA PATRICK: You need to put it in the fridge, and also make sure you’re getting a quality brand. So go to third party testing again. You want to have a total oxidation, ideally less than 10. And there are brands out there that do have an oxidation less than 10.
STEVEN BARTLETT: Which means it’s more fresh and pure.
DR. RHONDA PATRICK: It’s less oxidized. You don’t want to be consuming oxidized fat because that’s also not good.
Creatine: Benefits for Muscle and Brain
STEVEN BARTLETT: Okay, so what else jumps out to you here? We’ve got creatine.
DR. RHONDA PATRICK: Creatine is like my new — I travel with it everywhere. You’ve got micronized — is this —
STEVEN BARTLETT: I’ve got so many different types.
DR. RHONDA PATRICK: This is the one I take. I take creatine monohydrate because it’s the most well studied. I do a lot of resistance training and strength training, so I at least get 5 grams a day, which is what I always was doing in the past. I upped that to 10 grams a day as my baseline because I wanted to have benefits in my brain.
Studies out of Germany show that once you get to the 10 gram mark, your brain is actually able to take it up and it’s increasing creatine in certain brain regions. That doesn’t happen much at lower doses, because your muscles are very greedy.
The creatine in my brain, honestly, for me — I mentioned this before — it’s a game changer. Just on a daily basis, I feel like I don’t have that afternoon slump. I’m in my mid-40s, my brain isn’t as sharp as it was. Creatine has really helped me kind of get a little bit closer to where I used to be.
And also when I’m sleep deprived, I go up even higher. Sometimes I do 20 to 25 grams. That is because studies have shown that if you go up to a higher dose like that — depending on your weight, it’s kind of a scale — it helps you basically negate the negative effects on your brain from sleep deprivation, where not only are you cognitively functioning, you’re functioning beyond what your even normal baseline was, which was kind of mind blowing.
STEVEN BARTLETT: The question I had is around loading and how long it takes to feel the impact. Because when I first heard about creatine, I was 16 and my brother was bodybuilding and they were told that you need to load up on big loads of it, and then in like two weeks time, your body would be saturated. What’s the truth?
DR. RHONDA PATRICK: The reason that creatine loading was done was because there’s a short window of time when researchers are doing a study and they want their muscle stores to be saturated. You have to do a 20 gram loading phase in order to saturate them after three or four days.
If you are not about to compete and if you haven’t been using creatine and you’re not participating in a study, it takes about three to four weeks of 5 grams a day consistently to saturate your muscles. So you don’t have to do any loading phase.
If you are supplementing with 5 grams a day and you’ve been doing it for a month, your muscle stores are saturated. Until you exercise and you get that 5 grams in again, they’re saturated. That 5 grams a day is keeping them saturated. And that’s why I said your muscles are really hungry and greedy — they’re wanting that 5 grams, and that’s about what it takes daily to saturate them.
However, if you’re starting from ground zero where you’ve never taken creatine, it’s going to take four weeks to really get the effects. Otherwise, you’ll have to get higher doses — they’re not going to be saturated after 5 grams.
STEVEN BARTLETT: So some people might have tried creatine for a week, not felt any effects, and given up.
DR. RHONDA PATRICK: That’s actually a really good point. It’s about a month long experiment. I would say close to four weeks. Some people can saturate it at three weeks, but it all depends on body size and all that. So four weeks is a good experiment time, and 5 grams is a good dose to start with.
If 5 grams a day actually makes you more bloated and nauseous, cut that down to two and a half grams and split the doses. If you take it with food, particularly carbohydrates, it seems to help negate some of the bloating and nausea and negative effects people feel.
And obviously if you’re not working out, creatine’s not going to grow your muscles. You have to put in the work, you have to put in the effort. What it’s doing is it’s helping your muscles grow and giving you the energy to do more training volumes so that they can grow bigger and so that you can be stronger. If you are traveling and stressed and all those things, yes, creatine is good for the brain.
The Problem with Creatine Gummies and the Importance of NSF Certification
STEVEN BARTLETT: I was seeing — I think it was James Smith — he did a video about different creatine percentages in the creatine products we drink or eat or consume. And he looked at creatine gummies and found that some of the creatine gummies don’t even have any creatine in them at all. And it was quite shocking because you just assumed that if it says creatine, there’s going to be creatine in there.
DR. RHONDA PATRICK: This goes back to the whole problem where supplements are not regulated, and so you never really know what you’re getting. You have to have third party testing and go to a quality brand.
There was a consumer study that was published not long ago where people went and got a lot of different creatine gummies off the shelf and then measured how much creatine was in them. And essentially almost all of them had none. I’ve talked to some supplement manufacturers and their statement was basically that it’s really hard to get active ingredients into a gummy in general — not even just creatine, but in general.
The other thing I did want to mention with creatine is that you do want to make sure it’s NSF certified. That’s a really important thing because there are contaminants that are even produced in the processing of creatine monohydrate. And so you want to make sure that you’re not getting those contaminants, which can be harmful. Some of them are like lead, for example, but even some other compounds that are formed.
So you want NSF certification. That’s always what I look for when I’m buying a creatine supplement — NSF certification. Or any supplement, really. I really like to have all supplements NSF certified because that means they’ve, one, looked at contaminants, and two, it’s got that active ingredient in there. And that’s really what you want.
The Top Five Supplements
STEVEN BARTLETT: And the NSF certification is just a little logo on the side of the tube here that says NSF certified Sports.
DR. RHONDA PATRICK: That’s it. Yeah. And it’s all on websites too, if you buy online. Yeah.
STEVEN BARTLETT: Okay. So I’ve got one challenge for you. If you had to pick five supplements for me to take, assuming that I am male and female. Okay. So it’s neither gender and it can be things that are either currently in my cupboard or not. What’s the top five? And ideally, give me them in order, if you can. Order of importance.
DR. RHONDA PATRICK: Fish oil, number one. Number one, Vitamin D, multivitamin. All three, very, very strong evidence that you’re going to slow aging. You’re going to improve your brain function, lower disease risk, live longer, and creatine’s going to be there.
STEVEN BARTLETT: So that’s 1, 2, 3, 4.
DR. RHONDA PATRICK: And then the last one is magnesium. Magnesium would be. I mean, it might be number four and creatine number five, actually.
STEVEN BARTLETT: Really?
DR. RHONDA PATRICK: Yeah.
STEVEN BARTLETT: Are you sure? What is magnesium doing for me?
DR. RHONDA PATRICK: Magnesium is running. It’s important for 300 different enzymes in your body. It’s important to repair damage to your DNA. That’s being done all the time. It’s being done from the iron that you’re taking. It’s being done from normal metabolism, normal immune activation.
But when you’re in a state where you have — you’re not eating a good diet or you’re not getting enough sleep — magnesium is really important to repair that damage. And that’s why studies have shown that magnesium is really important for preventing cancer, and it also helps with sleep. It’s really good for sleep.
But more importantly, 50% of the population doesn’t get enough magnesium. And I bet you’re probably one of those people because most of us are. Do you eat a lot of dark leafy greens or almonds? You’re supposed to be getting about 350 to 400 milligrams a day. Are you physically active? Yeah. You’re sweating magnesium out.
Let’s make it six. Six supplements. So there’s a new supplement, Urolithin A, that I’m pretty excited about. The other thing I take that’s really important is that I don’t necessarily see here.
STEVEN BARTLETT: What’s it called?
DR. RHONDA PATRICK: So curcumin.
Phytosomal Curcumin and Inflammation
DR. RHONDA PATRICK: So phytosomal curcumin is another one that I supplement with. And let’s just start with curcumin in general. Curcumin is found in the turmeric plant. It’s something that is able to pretty robustly, and I would say consistently, lower inflammation. And it’s doing it in a different way than an NSAID, like an ibuprofen, would do it.
And that is important because it’s been shown that if you take NSAIDs — so these non-steroidal anti-inflammatory drugs, something like ibuprofen — around exercise, it can blunt the adaptations, because it’s basically lowering inflammation and prostaglandins and things that are important to cause exercise adaptations. So curcumin hasn’t been shown to do that, but it has been shown to lower something called TNF Alpha, and that is a major inflammatory cytokine that is really, really powerfully accelerating aging.
In fact, those epigenetic aging clocks that we talked about earlier — one of the most powerful drugs that’s able to slow them are TNF Alpha inhibitors. So these are drugs that people take to inhibit TNF Alpha. Certain people take them, like people with rheumatoid arthritis. They have a high level of inflammation, their immune system’s overactive, they’re making a lot of it. Well, guess what? Those individuals taking TNF Alpha inhibitors are like — they have a 50% less likelihood of getting Alzheimer’s disease than other people.
STEVEN BARTLETT: 50%?
DR. RHONDA PATRICK: Yes. So I like it because curcumin is one of the most — it is the most naturally occurring dietary compound that I’ve seen data showing that it lowers TNF Alpha. I haven’t seen anything else that’s naturally occurring that does it. This does it. It lowers it by quite a bit, by almost 5 picograms per milliliter.
Phytosomal curcumin — the reason I take phytosomal — it’s kind of like a liposome, but it’s a phytosome. So it’s essentially just making the ingredient get into the cells better. It’s more bioavailable because curcumin is easily metabolized quickly by the liver. It’s what’s called a xenobiotic. It’s not a compound that’s a vitamin or a mineral or something that the body normally recognizes. It’s seen as a drug, a foreign drug. Xenobiotic. And so the liver gets rid of it quickly. The phytosomal delivery of it kind of slows that whole process where it’s not getting rid of it so quickly, it’s not being metabolized so readily. So that’s why I take that.
And also, it’s been shown to improve performance in people that are exercising. Again, because it’s reducing inflammation. Inflammation can be dampening for performance.
STEVEN BARTLETT: And what else have we got here?
Urolithin A: Mitochondrial Rejuvenation
DR. RHONDA PATRICK: The other supplement that I really want to talk about is the Urolithin A. And as I mentioned, this is a compound that’s usually generated in the gut by the bacteria in your gut. It’s something that we can get from our diet. So if we eat things like pomegranate — pomegranate has a type of polyphenol in it called ellagitannins.
STEVEN BARTLETT: I’ve never heard about this before.
DR. RHONDA PATRICK: Okay, listen to this. This is like — you’ve got to try this supplement, Urolithin A. Again, it’s made from eating things like pomegranate. However, 50% of the population doesn’t have the right bacteria to make it. So you’re kind of like a coin toss. If you eat pomegranate, am I going to be the person that can make Urolithin A or am I not?
So there’s a company that did — out of Switzerland. A lot of these early studies were done in Switzerland, and they ended up making Urolithin A and then testing — doing clinical studies, doing animal studies first and then clinical studies — to test what Urolithin A is doing.
So what it is, is a compound that is able to basically get rid of damaged mitochondria. So it’s called mitophagy. You’ve probably heard of autophagy — getting rid of all the gunk and the trash from your cells, rejuvenating them.
STEVEN BARTLETT: Which is associated with fasting.
DR. RHONDA PATRICK: Fasting activates autophagy, fasting activates mitophagy, which is specifically just clearing out damaged mitochondria or pieces of damaged mitochondria. Autophagy is essentially — you have a whole cell, and within that cell you have a lot of different organelles. Mitochondria being one. So autophagy kind of helps clear out all this stuff inside of the cell. Mitophagy is very specifically just about the mitochondria within the cell.
Those mitochondria get older, and they don’t have a really good repair process, and so they accumulate damage. And as they get older, you’re not going to be making energy as well. You’re not going to be using energy as well. It’s going to affect all the cell function, because energy is at the core of everything. So mitochondrial health is at the core of all health, basically.
This compound very robustly induces mitophagy. And so there have been, of course, many animal studies that were done preclinically before clinical studies were done. Animal studies were exciting. Mice that were given — old mice that were given Urolithin A were able to rejuvenate tissues. But also, a 20% life extension was found in these mice given Urolithin A. 20% is pretty big for a mouse study. All right, but we’re not mice. So let’s talk about humans and why I’m actually excited about it.
For one, Urolithin A and mitophagy was shown to be activated in humans taking it. So they took muscle biopsies and found that, in fact, mitophagy was activated. It’s also recently been shown that Urolithin A is able to basically rejuvenate the immune system. So older adults were given 1,000 milligrams a day. And as we age, our immune system ages. Our T cells aren’t fighting off pathogens as well. And it increased the number of a very specific type of immune cell that decreases with age, called CD8 positive T cells. Those were increased. That’s very important because you’re able to fight off infection better.
And then it also increased a kind of immune cell that’s able to kill cancer cells and also kill viruses and pathogens. It’s called natural killer cells. So those cells increased as well with the Urolithin A, and it also decreased markers of senescence. So this is basically when a cell is still alive, but it’s not functioning. It’s basically like it’s dead, but not only is it not dead and not functioning, it’s secreting inflammatory cytokines, accelerating aging.
So the study showed that it was basically able to rejuvenate the immune system in older adults. Younger adults that have taken it — so there’s been studies showing that untrained athletes supplementing with 1,000 milligrams a day were able to improve their VO2 max 10% more than just exercise alone. So if they exercise and took Urolithin A, their VO2 max went up 10% compared to the exercise-alone group.
STEVEN BARTLETT: Wow.
DR. RHONDA PATRICK: Yes. If they were trained athletes, it only went up 5% because trained athletes already are doing a lot. So you always get a bigger increase in VO2 max if you have an untrained athlete. Same with obese people.
And on top of that — so again, energy. You’re clearing out damaged mitochondria. If you combine it with exercise, exercise causes you to make new mitochondria. So the way I look at it, Steven, is a rejuvenation of all your mitochondria within yourself, whether we’re talking about your muscle cells or your immune cells. I think it’s probably happening in the brain as well.
So it’s been shown to increase muscle strength in older adults. Their hamstring strength improved by like 10 to 12% after supplementing versus just exercise alone. I think it’s a supplement that’s important for aging because it’s affecting mitochondria. And pretty much everything relies on mitochondria.
STEVEN BARTLETT: You can buy this in a normal shop on the high street.
Glutamine, Ketones, and Peak Span
DR. RHONDA PATRICK: You cannot buy it in a normal shop. You can buy it online. It’s not cheap, unfortunately, that’s the other thing. So pomegranate itself is the next best thing for people. And there are studies showing that people that take pomegranate juice before they exercise over the course of several weeks can actually increase their VO2 max by up to 17%. This is analysis of multiple studies showing that.
So again, I think it’s all coming down to the urolithin A. And it’s a new supplement that I’ve been experimenting with. Again, the immune system effects, I think I’m not getting sick, but I’m doing the creatine, I’m doing the urolithin A, and I’m doing glutamine.
STEVEN BARTLETT: So glutamine is the last one. What is that?
DR. RHONDA PATRICK: Well, you’ve probably heard of glutamine as an amino acid, right? It’s so much more. It’s so much more. So glutamine is something that — it is an amino acid, but it gets converted into and metabolized to many different things. So one, it can be an amino acid. Two, it can form something called glutarate, which is used by your cells for energy. Mitochondria love it, or it can be converted into that neurotransmitter that we were talking about, right, glutamate. So it’s really something that can be used for many things.
I supplement with it because I came across some studies in the past couple of years where endurance athletes — so these are — I’m not an endurance athlete, but endurance athletes are very prone to respiratory illness because they’re really just going hard. And your immune system kind of takes a tax. Studies were showing that if those endurance athletes supplemented with glutamine, they didn’t get sick as often. They were having fewer respiratory illnesses.
And I remembered back to when I was a graduate student and I was doing research and I used glutamine — I was doing glucose and glutamine and looking at immune cells and how I could make them active, or what happens if I get rid of glucose or glutamine. And I remembered how much they love glutamine. They consume it, they’re using it for energy. And it started to make sense to me.
And this was during a period of time where, again, mid-40s, your immune system’s not doing as well as it used to. I had a young child that was bringing home all sorts of pathogens. And so I started supplementing with glutamine, and it could be placebo, but again, the sickness bouts were going down. I wasn’t getting sick as often.
The other thing it’s good for is the gut, and that is because glutamine can be converted into something called alpha-ketoglutarate, which is an important energy compound that the gut uses. And so there are studies showing that it’s beneficial for gut health. I think that’s what a lot of people think about when they take glutamine — is their gut. I’m thinking about my immune system, but basically it’s very easily used by the gut cells as energy, and that really helps the gut heal.
Exogenous Ketones
STEVEN BARTLETT: Okay. The other thing which I take almost daily — sometimes I give myself the weekend off, depending on how things are going, but almost daily — are these ketone IQ shots, which I am affiliated with. I’m an investor in the company. Ketone shots, exogenous ketone shots.
DR. RHONDA PATRICK: I take them also quite frequently, not daily. So what are they doing? There are different forms of them. And why do I take them? I think let’s talk about what I think people should realize if they are taking them.
So it’s essentially giving you that metabolic switch, right? It’s getting your ketone levels up as if you were fasted. So you’re elevating your beta-hydroxybutyrate levels. That’s the major circulating ketone.
STEVEN BARTLETT: Beta-hydroxybutyrate — BHB for short. Does that just mean ketone?
DR. RHONDA PATRICK: It’s a ketone. There are several ketones. Acetone is another ketone, but beta-hydroxybutyrate is the major one. And that is a major ketone that’s in your body when you’re fasted — that’s what you’re making. And when you’re taking these ketone IQs or other exogenous ketones, that’s what you’re going to get.
So ketone IQ has got the precursor for the ketone — it’s got 1,3-butanediol, that in your liver gets converted into beta-hydroxybutyrate. I take a ketone that has 1,3-butanediol, but also it’s esterified to the actual beta-hydroxybutyrate, which means that it has both an immediate action, a fast-action effect of having your ketones elevated, but it also has a tail-end effect. So the 1,3-butanediol, if you take it, you have to wait for it to get to your liver. Can I have one?
STEVEN BARTLETT: Yes.
DR. RHONDA PATRICK: Oh, perfect. Okay. Wow. Those taste better. So the other exogenous ketone is the beta-hydroxybutyrate esterified to the 1,3-butanediol, which just means it’s going to have a fast-acting effect but also a long-term effect. So you’ll get a little bit more elevation in your blood ketones from the one that has the beta-hydroxybutyrate esterified to the 1,3-butanediol.
STEVEN BARTLETT: That said, the difference is — I think from what I know, and I don’t know a ton — is pricing.
DR. RHONDA PATRICK: Yes, it’s pricing, but also again, concentration. So you’re going to get a higher peak quicker and you’re going to get higher levels of it with the one that’s the Oxford — the Oxford ketone, I guess it’s called. But the ketone IQ has 1,3-butanediol, which does get converted into beta-hydroxybutyrate.
STEVEN BARTLETT: This one I think costs a couple of dollars, and I have the Oxford one here as well, which I think is $30 a pop. So it’s quite expensive. And I think the reason why this has been able to break into retail, especially across America, is just because it’s more affordable for most people — to be able to spend a couple of dollars.
DR. RHONDA PATRICK: Right. The reason I take it is because I like the cognitive boost that I get from it. And I usually take it on occasions like this — when I’m doing a show, or doing a presentation, or I’m doing a lot of heavy research and I just need to be on — because I get a cognitive boost from it.
And that cognitive boost does come down to what I was talking about with why I like to fast. It’s mimicking that, right? I have that beta-hydroxybutyrate, which is increasing GABA — that inhibitory neurotransmitter that’s silencing down some of the anxiety in the back of the brain, or the chatter — and just helping me focus. And also it increases brain-derived neurotrophic factor. So beta-hydroxybutyrate is a signaling molecule. It’s able to increase brain-derived neurotrophic factor in the brain, that helps with learning, memory, and brain aging. It’s also been shown to lower oxidation. So there are all sorts of reasons why I like to take it.
For people that are fasting and they’re wanting to burn fat, consider that if you take exogenous ketones, you stop burning your own fat, because your body thinks it’s now got the ketones there — which is what the metabolism of fat is trying to do, is produce ketones for energy. And so it does shut down what’s called lipolysis, which is basically breaking down fat. And so if you’re doing fasting and you’re doing it for reasons of fat loss, and you take an exogenous ketone during that period of time, it will transiently kind of shut down that process. So keep that in mind. It’s one reason why I don’t do it every day, because I am looking for that effect for losing visceral fat in particular.
STEVEN BARTLETT: That’s a really interesting, important point that people don’t talk about.
DR. RHONDA PATRICK: Yeah, it’s important. And it’s only going to last as long as the beta-hydroxybutyrate lasts in your blood system. So maybe three hours max.
STEVEN BARTLETT: What I noticed was when I was trying to get into ketosis at the top of the year and I was doing exogenous ketone shots, I was struggling to get into ketosis. And so what I did is I stopped taking the ketone shots for a couple of days, just focused on my ketogenic diet. I got into ketosis, and then afterwards I started taking the ketone shots when I was doing podcasting, because just like you, I notice just such a radical, radical difference when I take exogenous ketones or when I’m in a natural sort of dietary ketosis.
And as a podcaster — I’ve said this a million times before, but I’m going to say it again — two times a week, I do an A/B test of how my brain is working. I sit with someone who is an expert in what they do for sometimes four or five hours, and I look at them in their face and I have to ask questions and respond and understand big words and hope that my brain is connected to my mouth today. And so I’ve done 600 or 700 of these A/B tests now. And one of the factors that correlates to good performance as an interviewer and a thinker, or a speaker on stage, is whether I’m in a ketosis state or not.
And it’s so profound — I’ve actually heard Joe Rogan say this. Joe Rogan said that the upside he gets from being in a ketogenic state is so evident for him as an interviewer that he’s considered being in that state all the time.
DR. RHONDA PATRICK: It’s the same for me, too. I mean, as you know, I’m also doing the same thing, right? I have a podcast and I’m giving presentations, and very much having to use my brain and be on. And it’s really made a huge difference for me as well.
And that is also why I like to fast, because I get the same effect when I’m fasted. And then I will take an exogenous ketone when I’m also fasted, and so I get into ketosis quicker as well, because I’m already kind of there. I don’t have other things inhibiting it. So it does help.
And there are again pros and cons to doing it. You do want your body to be metabolically flexible. So I’m glad you did the ketogenic diet and let your body kind of do it and adapt, and then add the ketones on top of that. But they do help. They help with cognitive function, for sure. I mean, I use them every single podcast I do, every presentation I’m giving. It’s part of my routine.
Peak Span: Beyond Healthspan
STEVEN BARTLETT: Let’s talk about something different, which is something that I’ve never heard of before. It’s a word that you’ve started to make popular in the health and longevity community, which is this idea of peak span. I have this graph in front of me, which I’ll throw up on the screen — it’s fascinating. What the hell is peak span? I’ve heard of healthspan, I’ve even heard of lifespan, but I’ve never heard of peak span.
DR. RHONDA PATRICK: Well, let’s start with lifespan and work our way to peak span, to give people a frame of reference. I think most people are familiar with the word longevity — wanting to extend their lifespan, how many years they live, how long they live. But the problem with lifespan is, well, you could live longer, but perhaps you have some diseases. So why do you want to live longer if you have Alzheimer’s disease or cardiovascular disease or type 2 diabetes? I mean, your quality of life is not as good.
And that’s where this idea of healthspan came in. So healthspan is, well, let’s increase the amount of time we live disease free. And that’s the new thing that everyone wants to increase and improve — their healthspan. I want to live longer and not have any diseases while I’m living that longer life.
Well, there’s this new concept now — very new — that was just published by some researchers out of Duke University, as well as, I think, a university in China and another university. But I want to give them credit — it’s a preprint study, and it came on my radar. I immediately loved it.
And this is the idea of peak span. Peak span says, hey, healthspan is great, being disease free is great, but you’re still in a period of decline. You’re still declining. Why not try to be as close to your peak span, which is essentially within 90% of your peak function for a certain measurement — whether we’re talking about VO2 max, cardiorespiratory fitness, or any other function.
And that’s where this graph comes in. On the Y axis, we have our relative capacity.
STEVEN BARTLETT: So if you’re listening now, this is a good time to look at the screen, because Rhonda’s going to show us something.
DR. RHONDA PATRICK: Okay, your relative capacity — 100 being 100% and 0 being 0%.
STEVEN BARTLETT: What does relative capacity mean?
Maintaining Peak Performance Across Your Lifespan
DR. RHONDA PATRICK: Your capacity for cognitive function, for your fertility, your potential, your hormonal — yeah, your potential. And on the x axis, we’re talking about age. And so what you’ll notice is that different capacities, different organ functions kind of peak at different rates.
So we can talk about first — obviously, female reproductive really starts to peak at around 25 or so, and then it just sharply declines until you hit 40, and it’s bottomed out. So that’s the reproductive female.
Immune function — let’s find immune function here. That kind of peaks around 25 years old, and it also kind of declines. And it keeps declining. It’s quite scary as you get to 80.
And then we have musculoskeletal. So this is our peak strength, peak muscle mass, peak bone density. Those also peak around 25, and then they kind of steadily start to decline.
And the same goes for cognitive function. We have two different kinds of cognitive function. We have fluid cognitive function, like processing speed. That is the kind of cognitive function where you can answer a question without any prior knowledge. That peaks around 25.
STEVEN BARTLETT: You’re joking.
DR. RHONDA PATRICK: No, I know.
STEVEN BARTLETT: So I’m on the way down.
DR. RHONDA PATRICK: I’m definitely on the way down. You’re on the way down as well. So that would be the blue one here — peaks around 25.
And then we have the crystallized cognitive function. Crystallized cognitive function is interesting because it peaks around midlife. And the reason it peaks around 40, 45 is because it’s the kind of intelligence — it’s like the library, where you have all these facts that you’ve accumulated over the years, and you’re able to use those facts to answer or solve a problem.
STEVEN BARTLETT: Is that wisdom, or is that —
DR. RHONDA PATRICK: It really just means that you have all these facts that you’ve learned over your life. Like, for me, I’ve been a biologist since I was around 20, so 27 years. I have so much that I’ve learned over that time. And so now I’m sitting here and I use that knowledge. I talked about glutamine and what I learned from graduate school. I’m using that knowledge. Mitophagy — I learned about that forever ago, and I’ve been following it. So you use all these facts and this data that you’ve learned in your life, and you’re able to solve problems. So fluid intelligence — I’m sorry — crystallized intelligence.
Entrepreneurship, Pattern Recognition, and Peak Cognitive Age
STEVEN BARTLETT: I’ve got to ask a question. There we were sat having dinner the other day, me and my team, and we were talking about the difference — because we’re all different ages. We’ve got someone in the team who’s 45, 35, 30, and the other person at the table was 27. And we were all talking about the differences we’ve noticed in ourselves as we’ve aged.
They all said different things. So Leona in my team, who’s just above the age of 40, was saying that she just doesn’t really give a f* anymore in the same way that she used to care about people’s opinions when she was 30. One of the things I said I noticed about myself was after I turned 30, I feel like I saw a step change in pattern recognition — exactly what you’ve just described there, which is like crystallized knowledge. Because I sit here with experts all day, learn all this stuff from them, and then my ability to then apply it in my life as an entrepreneur seems to be improving.
And so the question I was really going to ask you is — you think about entrepreneurship, a lot of my audience are entrepreneurs in some capacity or aspire to be — I was wondering, as you were saying that, when is the best age? Because entrepreneurship is a lot about pattern recognition. It’s a problem in front of you, and you think, “Okay, I’ve seen this before,” pulling on different reference points to arrive at a solution. So I was wondering here, because it looks like it peaks at like 45.
DR. RHONDA PATRICK: Yeah, 45. So if we look at it, it’s peaking at 45. And that’s also why a lot of biologists continue to do great work in their midlife as well. And that is something that I do feel like is better for me as well — where I’m now able to pull on so much of a database in the back of my head. I’ve got all this knowledge, and then it comes up and you can use it.
And so it’s interesting. You can talk about entrepreneurs, but any sort of career path would be beneficial to be able to do that.
So the question is, then, how do we get here — peak span? You’re going up, and what you want to do is you want to get and maintain about 90% of all these things that we’re talking about peaking. Immune aging actually peaks around adolescence, I think. Musculoskeletal health, 20 to 25. Fluid intelligence, 20 to 25. Cardiorespiratory fitness — that’s also 20 to 25. It peaks and then it goes down.
The question is, how do you maintain your peak span? How do you get as close as you can? You’re obviously not going to be your 100%, but how do you not drop below 90% of that peak?
STEVEN BARTLETT: Is that possible?
DR. RHONDA PATRICK: First of all, is it possible? And I would say for some organs — no. Which organs are that? I don’t think reproductive life expectancy for a female — I don’t think you’re going to be having babies at 80 years old without actual medical intervention. That’s a whole other conversation.
But I do think there are ways that we can get really close to our peak for cardiorespiratory, for musculoskeletal, for our cognitive intelligence, as well as our immune system. And I think there are blanket things that we could do that affect multiple systems. There are also targeted things.
So we were talking about fluid versus crystallized intelligence. Obviously crystallized intelligence doesn’t peak until mid-40s. The things that you can do to improve crystallized intelligence also improve your fluid intelligence. What are those things?
Number one — exercise. Aerobic exercise is increasing brain-derived neurotrophic factor, which is very important for both these aspects. It’s also growing new neurons, making connections between the neurons, making your brain more plastic and adaptable so it adapts to the changing environment. Top thing that you can do.
Another thing that’s really important for brain aging is Omega-3. We talked about that — really important for brain aging.
But the other thing that you can do is what we’re doing right now — engaging in novel cognitive experiences. It could be a discussion, it could be your work. If you are learning new things — novel is key here — you are going to really help yourself improve both your fluid and crystallized intelligence.
Cognitive Reserve and the Power of Novelty
STEVEN BARTLETT: Is that because you are raising your potential — so you’re falling from a higher place as you decline? Because I was thinking about this — how much of this has got to do with making sure that I peak at a higher place?
DR. RHONDA PATRICK: Yeah. I mean, I think that maybe has something to do with it. But in addition, there are neurochemical things that are changing when you’re learning new experiences. For one, you are increasing brain-derived neurotrophic factor, because novelty does that. You’re also having glutamate being activated as well.
But yeah, I think the cognitive reserve is what you’re talking about. And that is really important, because you need to have that reserve if you’re going to start pulling from it.
And that also comes with muscle health. Muscle and bone — those are peaking around the same times, around 25 or so. Peak muscle mass generally occurs around the age of 25. There are things that you can do to keep close to that peak though, and that would be resistance training — big, big, big one. Strength training. Strength goes down. Protein intake.
STEVEN BARTLETT: Avoid the black plastics in my fridge.
DR. RHONDA PATRICK: Avoid black plastics in your fridge.
STEVEN BARTLETT: Yeah, because then my testosterone is going to go down.
DR. RHONDA PATRICK: Testosterone is going to go down, and that’s going to affect your ability to gain muscle mass. Exactly.
A lot of these healthy lifestyles that we’re talking about are multi-system targeting. Key would be strength training and resistance training, and it’s going to also affect your bones. So you’re going to want to do these weight-bearing exercises that are multi-joint — the compound lifts. The deadlifts, rows, things like that. Those are very important to help maintain that peak.
Immune system — sleep. Very, very important for maintaining a healthy immune system and preventing your immune system from aging rapidly. So making sure you’re prioritizing sleep. There are a lot of ways — a lot of people have sleep problems for different reasons, and there are ways to target them. But just thinking about it and prioritizing it is important for your immune system and for your brain.
Exercise also plays a role in your cardiorespiratory fitness, the brain, everything — muscle. Cardiorespiratory fitness is something that we talked about — urolithin A helping improve it on top of exercise. So there are supplements that you can add in as well.
But this idea here is really that we can do things in our life that are healthy to help maintain that peak span — to get us not just free of disease, but close to what we were peaking at. And I do think it’s possible. I mean, we talked last time I was here about that study — you exercise five hours a week, do some high-intensity interval training in there, and you can reverse heart aging by 20 years. That’s incredible.
STEVEN BARTLETT: It’s crazy. So crazy. And you’re also saying that listening to the Diary of a CEO obviously is therefore good for —
DR. RHONDA PATRICK: Yeah, it’s good for your fluid intelligence and your crystallized intelligence. It’s good for learning new things.
STEVEN BARTLETT: So you would prescribe it.
DR. RHONDA PATRICK: Yeah, yeah. Especially the episodes I’m on.
The Unintended Cognitive Benefits of Lifelong Learning
STEVEN BARTLETT: I say that as a joke, but actually it’s part of the conversation we had the other day at dinner — I don’t think I’m going to appreciate maybe until later in my life how much an unintended consequence of doing this as a job had on my cognition and my brain. It’s not something that I would notice in the moment, but over time — doing this two times a week, sometimes eight hours a week, learning something new, being forced — “forced” is a strong word, but having an obligation to learn something new eight hours a week for my entire adult life — it’s great.
DR. RHONDA PATRICK: It’s one of the best things that you can do for your brain. That’s why learning a new language is associated with a rapid decrease in Alzheimer’s disease risk. You’re working your brain, you’re learning new things. It’s so important. One of the worst things that someone can do is retire and just sit and watch TV. That’s like the worst thing — you’re rapidly going to decline and get dementia.
AI, Critical Thinking, and Brain Rot
STEVEN BARTLETT: We’ve got to talk about AI in this conversation.
DR. RHONDA PATRICK: Oh, my gosh.
STEVEN BARTLETT: Because I actually woke up this morning and I got a message — look, I’ll check with him that I can put this in before I say it out loud, before it’s published. But I got a message from my chairman, Nicky. Nicky’s an incredible man — 25 years at Boston Consulting Group, he’s seen it all. And he said to me that one of the things he’s thinking a lot about at the moment is how, across our businesses but just generally in society, AI is going to impact critical thinking, and what that then might mean for our teams, our executives, et cetera.
So this is a conversation I was having this morning with him, and it’s also something I’ve noticed. There are certain people I interact with now where I do not feel at all like I’m dealing with their brain. I feel like I’m dealing with what came out the other end of a ChatGPT prompt.
DR. RHONDA PATRICK: Yes.
STEVEN BARTLETT: Good, bad, indifferent — I don’t know.
DR. RHONDA PATRICK: Yeah. It’s an interesting and important question, Steven, because I’ve been thinking a lot about what with AI — it’s changing so much. And the question is, do you focus on the negative parts and the short-term parts? Do you focus on the potential benefits that could be great and grand?
I do think a lot of it is people are worried about things like, “Oh, AI is going to take all of our jobs,” or “We’re going to have brain rot because we don’t use our brains anymore.” And those are concerns to have. But there’s also a lot of exciting things to think about.
I also worry about the brain rot part, where it’s like, well, okay, these people aren’t critically thinking for themselves. I can spot AI a million miles away. A million miles away.
STEVEN BARTLETT: Right.
DR. RHONDA PATRICK: And part of it is — if AI is accurate and people are more easily accessing the accurate information and they’re learning it, that’s great. That’s what it’s supposed to be there for.
AI, Exercise, and Brain Health
STEVEN BARTLETT: I think that’s a big if. Right, if.
DR. RHONDA PATRICK: Right, if. And it does have a lot to do with the version of AI you’re using. It has a lot to do with the prompt. It has a lot to do with the question, how much reasoning it has to do. It’s still evolving. But I agree. The worry is, are we going to have a generation of people growing up that don’t know how to critically think?
STEVEN BARTLETT: You’ve heard about that London taxi driver test experiment? I think I’ve heard you talk about it before, actually.
DR. RHONDA PATRICK: Yeah. They have these maps in their heads. You have these taxi drivers in London that they don’t use GPS. They know everywhere to go. By the way, I was in London a couple of years ago. I love the taxi drivers there. They are so awesome. They are just different. They’re totally different — for anyone that doesn’t know.
STEVEN BARTLETT: And I’m absolutely going to butcher this. To become a London taxi driver, you have to take a test for many, many years. You have to learn for many, many years. You have to learn every street across London from the top of your head without using GPS. That’s incredible. So when you get in a black cab in London, it’s amazing. You can go, “I kind of want to go to…” And they go, “Got you.”
DR. RHONDA PATRICK: They know everywhere. They have maps in their brain. Think about the cognitive reserve they have. Think about all the things they learned and the spatial memory and all that. And do these guys ever get Alzheimer’s disease? I don’t know that they do. There are studies out there showing that these types of taxi drivers do not get Alzheimer’s disease.
STEVEN BARTLETT: They have to learn 25,000 streets, and it’s called “the knowledge.” And they have been found to have physically larger hippocampus centers in their brain, which is the memory center.
DR. RHONDA PATRICK: And I like to extrapolate, if I may, and think that all this cognitive learning that I do daily — and that you’re doing by talking to guests from all sorts of fields — is also very… I mean, you’re learning things. You’re interested in things and you’re learning them, and it really is also a type of brain exercise.
So I think that this is ultimately what we were getting to. Essentially, if you can engage in intellectual types of activities, or anything that’s going to exercise your brain — whether it’s learning the map of London or it’s learning about mitophagy — it’s really good to engage in that novel learning. It’s really good for your brain. It’s working your brain out.
The Bifurcation of AI Users
STEVEN BARTLETT: I’ve been thinking a lot about this. I’ve just come back from South by Southwest, and every conversation was about AI.
DR. RHONDA PATRICK: I was there too.
STEVEN BARTLETT: They were asking me a lot about AI. So before I went on stage, I was looking at some of the studies and I concluded that at the moment we are in society, there’s going to be a bit of a bifurcation of people.
One group is going to take the path of least resistance with AI, which is they’re going to defer their thinking to AI. One of the things I learned from people like you often is that if you don’t use it, you lose it. And that part of their brain, whatever it is, will begin to atrophy to some extent.
And I think there’ll be another group of people who will — just like we go to the gym now, because we have to, because our lives are so easy — they will go to the mental gym, which means they will set aside time to intentionally solve difficult cognitive problems or challenges.
I’ve literally said to some of my executives, when we’re talking on WhatsApp or Slack, “Let’s try and solve this problem with our brains.” Because I believe that solving this problem with our brains will create a deeper understanding of the first principles of the problem — not just the surface level “one plus one equals two,” but what is one? What is a number?
This is the difference. AI can give you the answer, but it’s not going to give you the foundation so that you can solve other problems in the future. Because if I never told you what the number one was, you would never, in the future, be able to use it yourself. All you would know is one plus one equals two. But there are foundations — what are numbers? What is one, what is two, what is plus? — that you need to understand to be able to do one plus two equals three.
One of the studies I looked at, which has been heavily discussed, was from last year. They found staggering memory cost using generative AI. In this study — which I’ll throw up on the screen — 83% of AI users were unable to remember the details of a passage of text that they had written with AI’s assistance. EEG scans showed that brain connectivity was almost halved when individuals outsourced their thinking to AI compared to writing manually, which created cognitive debt. You get output faster, but you don’t build the long-term neural hardware to understand the information or the knowledge.
Writing, Memory, and Cognitive Reserve
DR. RHONDA PATRICK: So true. You know what’s interesting about what you just said is when you’re writing something — whether you’re typing it, or even, I think there have been some studies on this, handwriting something — something about handwriting really ingrains it into your memory.
I have this process when I’m trying to remember a lot of facts. The first step is the research — you research it and you find it. Then I type it in a Google Doc, and then I write it. And that process is really what gets it into my memory. All the statistics — and statistics are always harder because it’s just a number — versus understanding the fundamental nature of something that you’re interested in. That always helps.
So it’s interesting that if you’re writing something — typing it or handwriting it — even that really does help you remember something. If you’re just copying it and then trying to do some recall, it’s not going to work.
And then there’s the whole other layer you were talking about, which is the novelty isn’t there. You’re not really into it and learning. And that’s what it really takes to build that cognitive reserve, to improve the connections, to increase brain-derived neurotrophic factor. You need that novelty.
So I do love AI, but I also know that I need to continue using my brain. I have my own protocols that I like and that I still do. I still write things down. I have my little notebook. And before I go on a podcast, I like to go through and write stuff down that I’ve already typed, that I’ve learned, and things I wanted to cover. It really makes a difference in memory. So for people that are like you and I — learners and optimizers — take that pointer, because it really does work.
STEVEN BARTLETT: This was one of my favorite things with the iPad. I’m not the type of person that does a huge amount of writing on pen and paper, although I would do more because everything you’ve said is proven to be true for me. If I write something down, it’s like I’m writing it directly into my brain.
But the iPad now allows you to split what you’re reading — a book on one side and a notepad on the other. So what I do when I read is I read the thing and then I try and write out the lesson on the other side of the page. So I’ll say, “The gut microbiome has 42 trillion bugs.” And I’ll go, “The gut microbiome has 42 million bugs.”
DR. RHONDA PATRICK: Love it. I love it.
STEVEN BARTLETT: And then I turn the page. So I’m trying to do exactly what you said, because I realize that a lot of stuff I learn doesn’t land unless…
DR. RHONDA PATRICK: Right.
STEVEN BARTLETT: I write it out myself.
DR. RHONDA PATRICK: It’s something about the act of writing. And if you add the layer of what I do — it takes time — so you type it and then write it. Then it really sticks in your brain. Those are the ones that have really stuck when I’ve done them both.
But I love that. I don’t use iPads ever. I still read books — old books. When I have time to do them, I just have my notebook.
STEVEN BARTLETT: I think it shows, though. You have an unbelievable ability to remember so many things.
DR. RHONDA PATRICK: But I still love AI. I think there are a lot of benefits, and I think that scientists in general are using AI as their collaborator now. It’s a pretty smart collaborator that has access to a lot of data and can analyze a lot of data quickly.
Exercise Guidelines: Are They Good Enough?
STEVEN BARTLETT: What are your thoughts on exercise and the current suggestions and recommendations around exercise?
DR. RHONDA PATRICK: Well, I’m glad you asked this question. I’ve been thinking about this a lot. I did a podcast on the current exercise guidelines and I think they need to be updated. I think they’re not good enough.
It’s important for people to realize how these exercise guidelines were formulated and what they mean. Typically you’ll hear: 150 to 300 minutes a week of moderate intensity exercise is good for optimal health, or 75 to 150 minutes a week of vigorous intensity exercise. So they’re basically a two-to-one ratio — twice as many minutes for moderate intensity as vigorous intensity.
What is defined as moderate versus vigorous? That’s also important because it’s different across different studies. In these guidelines, moderate intensity is basically walking — moving with intent, but not really fast. Walking at a fast pace, but not jogging or running. That kind of activity would be considered moderate. Vigorous would be considered jogging, running, swimming, cycling — the kind of activity where you’re actually moving fast with intent.
Why do we have this two-to-one ratio? Where did it come from? It all came from energy expenditure. You burn twice as many calories doing vigorous intensity exercise as you do doing moderate intensity. If you’re walking one mile, you’ll burn X amount of calories. If you jog that mile, you’ll burn twice as many calories. That’s where these guidelines came from — the two-to-one ratio. Weight loss, energy expenditure.
But that’s not necessarily what’s important for reducing cancer mortality, reducing cardiovascular-related mortality, reducing all-cause mortality. These guidelines used that data — this two-to-one ratio of energy expenditure — and then looked at other studies and said, “Okay, how much exercise is required to reduce cardiovascular mortality or all-cause mortality?” And they kind of connected the dots. By the way, these studies also were using questionnaires. They weren’t actually measuring how active people were.
A new study came out, and I did a journal club podcast on it because I felt it was so important that I wanted to break down all the components of the study with another scientist and talk about them. Journal clubs — typically in science you have them. In my career, it was sometimes once a week, other times once a month. Someone chooses a study that’s important, you break it down, you talk about the results, the methods, and what the findings mean. That’s what a journal club is. You choose a journal and a publication within that journal, and it’s a club — you have different scientists talking about it.
STEVEN BARTLETT: Why did this warrant a journal club?
The Power of Vigorous Exercise: Rethinking Exercise Guidelines
DR. RHONDA PATRICK: Because I think this study basically is strong enough data that it’s implying we need to change our exercise guidelines, at least the messaging of them, at the very least. And I’ll tell you why.
Because I talked about these guidelines, how they’re formulated, they’re using questionnaires, they’re not measuring anything. Well, a new study came out. Not only did it measure physical activity through these accelerometers, it was able to measure how active people were and the type of activity, whether it was — I mentioned moderate versus vigorous. They also measured light physical activity that would be considered walking around your house, kind of doing that kind of light activity, not necessarily going for a walk or going for a run.
And they looked at deaths from different causes of disease. They looked at deaths from all causes, so all cause mortality. They looked at cancer related deaths, they looked at cardiovascular related deaths. They looked at type 2 diabetes, they looked at heart attacks.
And what was so profound was that what we found — what they found and what we now know — is that everything changes in terms of how important vigorous intensity exercise is. It’s so much more valuable than we thought. It’s not two to one.
So if we’re looking at all cause mortality — dying from all causes, cancer, respiratory, anything related that’s non-accidental — for every one minute of vigorous intensity exercise, you had to do four minutes of moderate intensity and you had to do like 100 to 150 minutes of light exercise to get the same reduction in all cause mortality.
STEVEN BARTLETT: For every one minute.
DR. RHONDA PATRICK: For every one minute of vigorous intensity exercise. It gets better, okay?
For every one minute of vigorous intensity exercise, to reduce your death from cardiovascular disease, you had to do eight minutes of moderate intensity and 200 minutes of light exercise.
For every one minute of vigorous intensity exercise — it’s huge — to reduce your type 2 diabetes risks, for every one minute of vigorous, you had to do 10 minutes of moderate intensity, or you had to do again, you’re in the 150 to 200 minutes of light exercise.
To reduce your risk of dying from cancer, for every one minute of vigorous intensity exercise, you had to do about four minutes of moderate intensity. And for light, it was almost not even happening. It was like 250, 300 — just a ton of minutes, an unbelievable amount of minutes.
But the value of vigorous intensity exercise is so much more than this 2 to 1 ratio based on energy expenditure, based on burning calories, that our guidelines were based on. It’s time to rethink them. It’s time to tell people, “Hey, if you’re getting out and you’re going for a run, it is worth way more than you think it is in terms of reducing your disease risk and your death from that disease.”
Also, what was really interesting about this study — and this goes back to the exercise snacks that we talked about before in the last episode — is that because the participants were wearing these accelerometers on their wrist, they were able to measure all physical activity. Let’s say you have a new puppy and you’re sprinting in the yard and playing with them for a minute or two minutes or three minutes or whatever. Not 30 minutes in the gym, not 30 minutes on the treadmill, but just a short burst. Or you’re playing with your grandkids or your kids and you’re playing tag, whatever. Those moments count. They really add up.
And that is also a take home from this study and other studies — that you can actually get massive benefits from the sprinting, the vigorous exercise, one minute, two minutes, three minutes. Women that did three and a half minutes of just this vigorous type of exercise per day lowered their cancer risk by 40%. Yes, three and a half minutes a day. This was in women.
Now there are bigger studies showing men and women that exercise nine minutes a day — the short vigorous types of exercise, adding up, not nine minutes altogether, but like a minute here, a minute there, a minute here — it adds up. 40% lower cancer related mortality, 50% lower cardiovascular related mortality.
And that’s another big take home from this study that I really want people to know about. Because some people don’t like spending 30 minutes, or blocking out a 30 minute time or an hour long time to go to the gym. They should — if they want their peak span, that’s what you’re going to have to do. But if you’re just wanting to avoid disease and be in your health span, you can get that by doing these short bursts of physical activity, and those count.
And some people are like, “Oh, thank God, I can do that because I hate going to the gym.” They just won’t do it. They just won’t do it.
10,000 Steps a Day: Time to Ditch It?
STEVEN BARTLETT: A lot of people as well are caught up with this 10,000 steps a day thing.
DR. RHONDA PATRICK: Yes, 10,000 steps a day.
STEVEN BARTLETT: What’s that facial reaction? For people that can’t see your face, she looked up into the corner like I personally offended her.
DR. RHONDA PATRICK: Yeah, look, any exercise is better than none. I want to just get that on the table. That’s important. I don’t want to totally diss the 10,000 steps a day, but I think that we need to ditch it. I think we need to ditch 10,000 steps a day and say 10 minutes a day — 10 minutes a day of getting your heart rate up. You can do bodyweight squats, you can play tag with your kids or your grandkids, you can do shorter bursts of it. But it needs to be 10 minutes.
And if you get to that 10 minutes a day: 50% lower cardiovascular related mortality, 50% lower all cause mortality, 40% lower cancer mortality. That is what you’re going to get. 10,000 steps a day is not going to get you that. We just talked about it. It’s not going to get you that. It’s a different ratio. It’s not a two to one ratio.
Defining Vigorous, Moderate, and Light Exercise
STEVEN BARTLETT: I imagine there are people thinking you used three terms there — vigorous, moderate, and light. We probably need to quite clearly define those definitions. What is vigorous?
DR. RHONDA PATRICK: Right. Heart rate — is it all vigorous intensity exercise? It can be heart rate, and it is heart rate. In a lot of studies that are done in terms of the exercise guidelines, they don’t use heart rate, they’re using movement. When I say accelerometer, I mean moving fast. They’re able to measure the acceleration of your movement. And so the way that they’re talking about it in these exercise guideline studies is moving fast.
Moving fast would be jogging, running, swimming, biking — you’re moving. A stepper would be moving fast. Even weights — you’re moving fast. That’s part of it too. If you’re doing bicep curls or you’re doing something with your wrists that are fast, it’s part of that equation as well.
STEVEN BARTLETT: Heart rate isn’t the thing they were measuring, but that’s a consequence of moving fast.
DR. RHONDA PATRICK: It is.
STEVEN BARTLETT: So you want to be thinking about getting your heart rate up.
DR. RHONDA PATRICK: Personally, when I think about it — and if I’m talking about it in the context of these exercise guidelines — I would say that vigorous would probably be considered 70% or more of your max heart rate. Previously, when I’m talking about vigorous, I also talk about high intensity interval training, and that’s more like 80% of your max heart rate or higher. Very important for improving VO2 max and cardiorespiratory fitness.
But in these studies, heart rate is more like 70% of your max heart rate. You can be jogging at that rate. That’s vigorous intensity exercise. If you’re below that, if you’re like 50% of your max heart rate, that’s considered moderate intensity. And then maybe even lower than that, if you’re just walking around the house — that’s not even going up much at all. That’s light. That’s considered light.
10,000 steps would probably be considered — it depends, because actually they’re saying steps, which could just be around the house. If you walk around your house, how long does it take to do 10,000 steps? Like an hour, hour and a half?
STEVEN BARTLETT: Yeah. Probably just doing six or seven thousand just walking around the office.
DR. RHONDA PATRICK: But that’s considered light exercise. So that’s why I think we need to get rid of that. It’s not enough. It’s not enough. It’s better than sitting, because sitting is bad. Sitting is an independent risk factor for disease, for cancer in particular.
The Dangers of Sitting: Breaking Up Sedentary Time
STEVEN BARTLETT: This was one of the most replayed moments last time I spoke to you — people replayed the section where you talked about being sedentary and how much of an issue that is for all of us. And it’s really stayed with me to the fact — I don’t know if this helps, but I’ve been using standing desks everywhere, even when I travel around the world. I’ve actually got a portable standing desk just to try and keep me up. Because as a podcaster, I’ve sat in this chair for — I’ve sat down for six hours today, and it’s 3:00pm.
DR. RHONDA PATRICK: Yeah. Kelly Starrett wrote a book, Desk Bound, some years ago, and he really played a role in popularizing this idea in the public as well.
Being sedentary is time you spend sitting. It doesn’t necessarily mean — I used to think about being sedentary as, “Oh, do you work out? Yes or no? No, you’re sedentary. Yes, you’re not sedentary.” That’s not what sedentary is. Sedentary is time you’re spending sitting. We’ve been sitting here quite a few hours. We’ve been sedentary this whole time.
So being sedentary and sitting is an independent risk factor — even if you’re exercising, it’s an independent risk factor for diseases. I mentioned cancer in particular. That seems to be the one that’s more strongly correlated to being sedentary.
But standing helps if you’re standing up, or also getting up and doing exercise snacks. You can get up every hour and do some bodyweight squats, do some jumping jacks, do some high knees, get your heart rate up. That breaks up the sedentary time. So now it’s only an hour of sedentary versus eight hours, or six hours, or however long you’re sitting at your desk. It makes a difference.
And those exercise snacks are easy to do. I have a standing desk — I don’t use it enough, I still have it. I do do exercise snacks, and I like doing them because literally, if we were to get up and do bodyweight squats right now for one minute, you’re going to feel better. You feel better after — the blood flow to your brain, it gives you a little pump. I love it. I love the pump. It’s just one minute of it and you get a short pump to your brain and it makes you feel better.
So exercise snacks are a really good way to break up sedentary time. They’re also adding up — they count, as I just mentioned, they count towards your exercise goal, and they’re vigorous. You’re moving fast. Vigorous exercise. You’re getting your heart rate up.
GLP-1 Medications: A Shortcut to Health?
STEVEN BARTLETT: Or I could just take a Zempic. I just get the pen out, jab, jab, jab, and all of this stuff disappears. I could do all of this stuff, or I can just Zempic it, right?
DR. RHONDA PATRICK: Yeah.
STEVEN BARTLETT: So many people are taking Zempic. So interesting. And I have to say, it’s saving people’s lives. Amazing. I’ve heard so many of my friends who are on Zempic and taking the GLP-1 pens say that they’ve had profound benefits. Their knees are better, they can walk upstairs, they feel better.
GLP-1 Drugs: Benefits, Risks, and Who Should Really Be Using Them
DR. RHONDA PATRICK: Yeah. I mean, let’s be real here. Being obese and overweight is one of the worst things you can do for your health. It’s going to accelerate the aging process and it’s going to increase the risk of every age-related disease. Cardiovascular disease, type 2 diabetes, cancer — visceral fat is happening, you’re insulin resistant, it’s all happening. It’s going to affect your quality of life. It’s harder to walk around, you’re not as mobile, your joints are getting more stress on them.
So anything that can help you lose that weight is going to be beneficial. And so these GLP-1s you’re talking about — Ozempic, that’s the GLP-1 receptor agonist. They are very life-changing for people that are obese, people that need to lose 40 pounds, 50 pounds, 30 pounds. It’s not easy to lose that weight with diet and lifestyle.
So the benefits are, obviously, if they’re going to lose that fat, the visceral fat, they are going to become insulin sensitive. They’re going to reduce their risk for all those diseases. And that’s what the data shows. Cardiovascular disease risk goes down, cancer risk goes down — except for one type of cancer, which goes up: kidney cancer. But Alzheimer’s disease risk goes down. When you lose weight, those risks are going to go down.
There are side effects, and there are things to consider when you’re taking — I’m calling them GLP-1s because we have first generation, second generation, and now third generation. And they’re affecting not only the GLP-1 receptor, but they’re affecting glucagon, for example, and another peptide called GIP. So I’ll just call them GLP-1s for short. Semaglutide, or Ozempic, is one of the first generation. We now have the second generation that’s targeting two pathways — you can lose even more weight. Mounjaro would be something that people would relate to. That’s one of the second generation ones.
I think that for people that are going to start these drugs, first of all, they have to realize there’s a good chance they’re going to have to be on them for the rest of their life. That’s something that you have to be willing to do. And I say that because many studies have shown now that individuals that do take these GLP-1s do lose a lot of weight, and it’s very beneficial to lose that weight. But if they stop taking the GLP-1s, they gain the weight back. And oftentimes they gain all the weight back, because your body’s kind of trying to go back to that reset point, and their hunger comes back with a vengeance.
Part of what GLP-1 drugs are doing is they are basically making you feel satiated and not hungry. So they’re affecting your satiety hormones, so you don’t feel hungry. They’re also slowing gastric emptying, so food stays around in your intestines longer and you feel full. When food is in your intestines, you don’t feel hungry. So they’re slowing that process.
In many ways, it’s mimicking calorie restriction and fasting. You’re basically not eating as much food. But it’s doing it for you — you don’t have to feel hungry, you don’t have to put in that work. And so people are losing a lot of weight, and they’re losing it very rapidly.
And I said you might have to be on it for the rest of your life. What I mean by that is because a lot of studies show that the majority of people do gain back their weight. Their appetite comes back with a vengeance, and they regain the weight over a year or so. So that’s one thing to consider: are you willing to take it for the rest of your life?
STEVEN BARTLETT: There was a New York Times piece where they looked at a lady called Stacy Canterbury. She’d lost 50 pounds on one of the GLP-1s that you mentioned, reaching her peak goal weight. And after stopping the drug due to insurance issues, she regained 20 pounds straight away in a month. Interestingly, she described the return of hunger not as a gradual increase, but as a “ferocious, animalistic urge to eat” that was far more intense than before she ever started the medication. And the New York Times did a big piece about that. Because one of the things that I’ve come to learn is that there’s no free lunch in life — no pun intended.
Muscle Loss, Bone Loss, and Other Side Effects to Consider
DR. RHONDA PATRICK: There’s no free lunch. There’s no free biological lunch. It’s true. People’s appetite — that’s why I said it comes back with a vengeance. Because it seems to be the case where your body’s like, it hasn’t been hungry, and it’s like, “Wait a minute, I’ve been starving for so long, I need to eat.” So it’s kind of like, “Feed me.” And that’s obviously something to consider.
So the question is, well, what happens if you’re on these drugs long term? We’ve got these drugs — early versions of them have been around. They also help treat type 2 diabetes. That’s part of where they first came from. They’ve been around a while. We do have some data. Mostly the data is positive because people are losing a lot of weight, and that is what’s putting them at high risk for these diseases. And so when you lose that weight, your disease risk for all these diseases goes down. So it’s hard to uncouple weight loss from what the drug’s doing itself.
But there are side effects in addition to that. Nausea, GI upset, all that stuff — may be temporary. Some people, it kind of sticks around. Some other effects I think that people are a little more concerned about are the muscle loss and bone loss. That’s a big one. And that is probably something coming from just rapid weight loss and not eating enough food and not resistance training.
When you’re largely fasting throughout the day, if you’re not getting enough protein, then your muscle’s not going to have amino acids to help basically keep growing — and not only keep growing, but not use its own amino acid reserve for making protein. You break down muscle. In fact, there are weight loss studies showing that in any weight loss diet, if you’re not eating enough protein and you’re not resistance training, up to 40% of your weight loss can come from lean mass, including muscle. So that’s a big percent.
If people are resistance training, it really helps, because that’s a signal to your muscle to grow. It’s a mechanical force that helps you grow muscle. That’s something to consider.
Bone loss is another one. You can also lose bone from rapid weight loss. I don’t know if there are independent GLP-1 receptors on bone doing something directly there yet to be uncovered. I think we don’t really know why bone loss occurs. It’s thought maybe it’s just the weight loss, but maybe there’s something that we don’t understand yet.
Kidney cancer is another one. It seems like there’s an increased signal for kidney cancer. Don’t know why that is — it needs to be studied. There’s a black box warning on them for thyroid cancer increase. That’s never really been shown in human studies. It all comes from animal data. But it’s there nonetheless — something to consider.
STEVEN BARTLETT: And it’s very early. So I feel like we’re going to have a conversation in five years’ time when there’s more understood about these compounds.
Who Should — and Shouldn’t — Be Using GLP-1s
DR. RHONDA PATRICK: Well, the thing that worries me is that, okay, you have the person who’s 300 pounds and they have to get down — that’s really unhealthy. That can really be a game changer for them. But now what we’re seeing is Hollywood, we’re seeing just your average moms. They’re like, “I want to lose 10 pounds, but I want it to be easy.” They’re 10 or 15 pounds overweight, whatever, and they’re going to these GLP-1s.
The question is, I don’t know that we have data showing it’s actually beneficial in that population, because they’re already pretty lean and they’re just wanting to look a little bit better. We don’t really know if it’s beneficial. We know that losing weight is beneficial for sure, and that’s what these drugs are doing. You’re losing a lot of weight rapidly.
The other thing is gallstones. You’re getting an increased risk of gallstones. Some people’s gallbladder has to be removed.
STEVEN BARTLETT: What about anorexia and stuff like that? Because I’ve got a couple of friends who are on the pen, and they have dropped weight at a speed that has blown my mind. And part of me is going, “Stop, stop, like, stop here.” I’m thinking, does this just keep going down and down and down and down?
DR. RHONDA PATRICK: I don’t think it keeps going down and down and down and down. Generally, I think you kind of hit a certain point and stay —
STEVEN BARTLETT: If the dose remains the same.
DR. RHONDA PATRICK: If the dose remains the same. And I think that people that are already at a certain healthy weight should taper down the dose too. And that’s also been shown to help, at least with weight regain. If you want to stop and get off it, you have a better chance of success if you taper down the dose and don’t just full stop get off of it. It seems like tapering down helps people at least slow the weight regain, where it’s not happening all of a sudden — your body kind of adjusts.
But I also want to mention, there are other ways that you can lose weight. Intermittent fasting, for example. On the lowest dose of some of these drugs, like Ozempic, if you’re on the lowest dose, you can achieve a similar amount of weight loss from intermittent fasting as you do from that. And that’s not a huge amount — maybe 5 to 10% body weight. But for people that don’t need to lose a huge amount, that’s a good way to do it, because you’re going to get the metabolic switch, you’re going to get the ketosis. You’re not going to have to worry about the side effects. You don’t have to worry about regaining the weight, because your body adapts — you get used to the fasting, it becomes easier.
So I think it depends on the population we’re talking about here. Do I have concerns? Yes, I do. But do I also think some of these people that are obese and would never lose that weight are getting a benefit from these drugs? Absolutely, I think they are. But it all comes down to the population who’s using them. And right now it’s become so popular, and there are so many people I don’t think need to use it to lose their 10 pounds. It’s ridiculous.
STEVEN BARTLETT: People take the path of least resistance though, don’t they? And this appears to be the path of least resistance for many. So we shall see, I guess.
Closing Question: The Best Purchase Under $100
STEVEN BARTLETT: Rhonda, we have a closing tradition where the last guest leaves a question for the next, not knowing who they’re leaving it for. And the question left for you, I think, is a great one. What is a purchase that you made that is less than $100 that improved your quality of life the most?
DR. RHONDA PATRICK: I have two. I would say the Omega-3 index test — that is measuring your omega-3 fatty acid levels.
STEVEN BARTLETT: And you can get that at home?
DR. RHONDA PATRICK: You can order it online and get it at home. You do a little spot of blood — it’s like a finger prick blood spot. And just knowing that you’re in that 8% range — the 8% range is the five-year increased life expectancy, it’s the 66% lower dementia risk. It’s really where you want to be to be the healthiest. And you might be supplementing with an omega-3 supplement that’s not really working, and you won’t know it unless you take that test. I think it’s one of the easiest ones that I’ve done.
STEVEN BARTLETT: And how did that improve your quality of life? Or are you saying it helped you avoid a bad quality of life?
DR. RHONDA PATRICK: No, I think it’s improving my quality of life because it’s slowing my aging. That’s been shown with omega-3 — it’s absolutely slowing aging. I told you, the omega-3 was the only supplement that was able to do that, even in the context of people that were healthy and physically active. I mean, these Swiss people are healthy. If they did this study in the US, there’s no way that 88% of them would be physically active. Not a chance.
So it’s slowing the aging process, and that is exactly what I want to do. It’s going to help with peak span, it’s going to help with health span, it’s going to help with lifespan as well. And it’s affordable — less than a hundred bucks.
And the second one — the one that really did improve my quality of life — was a continuous glucose monitor.
STEVEN BARTLETT: And I thought you were going to say creatine. Okay, continuous glucose monitor. Oh, no, no, no, you can’t go back now.
Continuous Glucose Monitoring and Closing Thoughts
DR. RHONDA PATRICK: Yeah, it did, it did. Because I realized how important sleep was for my metabolic health. I thought I was doing everything right for my metabolic health. And it was knowing how not getting enough sleep was affecting my glucose. I never would have thought that, never would have known. And most people that get the continuous glucose monitors never think about that either. They think about the food they’re eating, they don’t think about sleep.
STEVEN BARTLETT: And when you get that continuous glucose monitor, what is it you’re looking at to figure out the connection with sleep?
DR. RHONDA PATRICK: You can look at first? You can look at your fasting blood glucose levels and you can go online and for your age and gender and figure out what’s a normal range.
STEVEN BARTLETT: So that’s when you haven’t eaten.
DR. RHONDA PATRICK: Yes, first thing in the morning and you have not eaten. That would be the easiest thing to look at.
STEVEN BARTLETT: And the second thing.
DR. RHONDA PATRICK: Yes, the second thing would be to look at after you eat a meal 30 minutes to an hour later, making sure that you’re clearing that glucose from your meal. And if you’re not seeing that peak come down and clearing, there’s something wrong.
STEVEN BARTLETT: Okay, I might wear another one of those. It’s been a while and they’re quite cheap. You can get them for like $20 on the Internet. Dr. Rhonda, I think people are going to want to continue to learn from you. So where should they go to learn more from you?
DR. RHONDA PATRICK: I have a podcast called FoundMyFitness. It’s on YouTube, Spotify, Apple Podcasts, everywhere you listen to podcasts. That would be the best place. I have a website, foundmyfitness.com. I have a wonderful newsletter. Every week we put out something. We put out one on that peak span paper. We put out a newsletter on updating the exercise guidelines. I have a great team. We put out an email newsletter that’s free every single week. And they’re really good. They’re really good in depth emails, so people can find me there. I’m on social media. Rhonda Patrick. Found My Fitness. That’s all my — that’s my handle, my website name, my podcast name.
STEVEN BARTLETT: I’ll link it below for anyone as well that would like to go check out that information. It’ll all be in the description below. I highly recommend. I mean, I don’t really need to tell people how incredible you are. I think they’ve just observed that. So I shan’t. I shall. You are incredible.
DR. RHONDA PATRICK: Thank you.
STEVEN BARTLETT: So thank you so much for doing this. I’ve learned so much and I’ve done so many of these health conversations on this show, and it’s almost at a point now where I’m wondering if there’s much more that I’ve got to learn. But because I think you stay at the very cutting edge of the studies that are coming out, and you’re so good at both articulating them in a simple way that someone like me can understand, even though I can’t understand a lot of the literature as it comes out of these sort of scientific journals.
I think that you’re a person people do need to follow because the world and the scientific understandings are always changing. And it’s good to have someone who can distill that down for you in a way that is relevant, accessible, and scientifically rigorous. And that’s exactly sort of the three terms that I think of when I think of you.
So please do continue to do the work you’re doing, because it’s teaching me so much. And by way of that, it’s meaning that I can live a happier, healthier life. And I appreciate you for that. Thank you, Rhonda.
DR. RHONDA PATRICK: I really appreciate that. Thank you so much, Steven. I love coming and having discussions with you. They’re fun.
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