Title: Origins and Evolution of the Western Diet: Health Implications for the 21st Century
Speaker: Dr. Loren Cordain
Dr. Loren Cordain – Author, The Paleo Diet
Wow! What a warm welcome. Thank you so much Pensacola. So I want to thank Dr. Ford for the cordial invitation down here. Also I want to thank Roger and [Orthane] their courtesy for providing me with the house. So very much appreciate it. So let’s just go ahead and get into it.
This talk is based on a scientific paper our research group published in American Journal of Clinical Nutrition in 2005 [http://ajcn.nutrition.org/content/81/2/341.full], and to say the least I’ve got an incredible mileage out of this paper. It’s taken me all over the world. So as a matter of fact, I’m going to be — where am I going to be — I’m going to be in Rome in two weeks giving a similar talk. So lot of mileage on this.
All right. So any time we’re talking about the origins and evolution of the human diet, what we’re really talking about is the origins and evolution of humanity itself. And so let me walk you through this slide because this is going to set the stage for the rest the lecture. And if you look carefully up here, there’s a couple of key items that we need to consider.
The first thing is the word “Hominin” and what hominin means is a bipedal ape. And so what all of these little boxes here, these rectangular boxes, represent are hominin. So these are different species of our ancestral humans, and the length of the box indicates the time in the geologic record in which we find these fossils. And so these ones that are labeled in green right here, we’re not sure if these are apes or if these are hominins. So these are kind of the last common ancestors and you notice then that the period at which we became hominins and bipedal happened roughly 5 million to 7 million years ago.
And as we move in this direction, you can see these pink boxes represent our own genus Homo. And so as we move further on up, you can see that here is homo sapiens. And homo sapiens, our own genus and species, only have been around for about 200,000 years. And there are no other hominins that are left, we are the remaining ones.
There’s two key periods that we need to consider for this lecture. And one is the Pliocene. The Pliocene goes back to 5 million years ago and then we need to look at the Pleistocene. The Pleistocene happened about 1.7 million years ago on up to the present. And this is when really all the action happened when we became human. And so we believe that diet was one of the environmental factors, perhaps the most important environmental factor that allowed us to become human. And we’re going to get into this issue with the lecture.
So there may be as many as 20 hominin species that existed. They simply did not have one diet. We talk about the Paleo diet, or the Paleolithic diet, the Old Stone Age diet. There really wasn’t one diet and that diet varied by geographical locale, season and other factors.
So let’s talk about that period — the Plio-Pleistocene and what do we know about that period for sure. So we know that our ancestors ate an omnivorous diet. They ate both plant and animal food. The difference between their plant and animal foods compared to ours is that they were wild and unprocessed. They simply did not have the technology to process their foods. So these are some really cool photographs taken by Richard Lee at Harvard and these photographs were taken of the Kung people in the 1960s and – late 1960s. And so if you look carefully up here, I know the people up front can probably see this. But this fellow actually has a stone tool at his hand and this was an experiment to see if you could butcher African animal with the stone tools and it turned out they were very effective tools at butchering and disarticulating the carcass.
If you look up here now these guys are sitting around doing nothing and of course the women have gone out and gotten all the food. And so we’ve changed so much, haven’t we? So you can see right here, if you take a look carefully, I know in the back it’s going to be a little bit more difficult, if you can dim the lights but I guess we cannot. But you’ll be able to see that — look at the size of her fist right here and then look at the size of this thing that looks like a watermelon, it’s a tiny little watermelon and indeed that’s where watermelons came from, they’re indigenous to Africa. So she’s gone out and collected these melons. These are called tamma melons. And if you notice over here, here are some berries and here’s some roots right here. And see the stick that’s how she dug up these roots, is with her little digging stick. And right here in the middle, I guess you can see it, I’ve given it away but that’s a tortoise. So when women go out and gather they get both plant and animal foods.
So what can we say about the Plio-Pleistocene diet and how do we know that it was omnivorous? What is the evidence to support that notion?
We look at our closest living ancestors, that last common ancestor about 5 million to 7 million years ago, probably didn’t look a lot like a chimpanzee and it didn’t look like us. It looks like something in-between because chimps have evolved as well. But chimps are primarily frugivorous, they eat a lot of fruit in their native environment. But they also eat a lot of meat during the dry season. And if you look carefully right here, this is a male chimp and they go out in the forest in packs, probably four to seven males or even more and they chase around these little colobus monkeys and they also chase around small antelope. And they catch them with their hands but they don’t have large carnivorous carnassial type teeth to be able to tear apart the flesh. And so how they kill them is they body slam. They grab them and then boom, they pound to the ground and then it takes them forever a day to disarticulate the carcass with their small teeth. And they literally eat everything. They eat the brains, the break open the bones and eat the marrow and eat the meat and so forth. So they eat close to a quarter pound of meat a day during the dry season. So that is indicative that perhaps all hominins were meat eaters.
This is even more powerful data. This is a stable isotope data. And if you look carefully up at this fossil. This is one of more famous fossil. This is called the Taung Baby. And you see that if you look at the teeth right here, the enamel is still intact on the teeth and because of that it allows us to go into this tooth and measure an isotope called delta 13 carbon. And by analyzing this isotope we can determine what this particular creature has been consuming. And so if there’s more of these C3 type foods, this is a browser. This is an animal that consumes the leaves, shrubs and herbs and if there’s more of this C4 isotope, it’s consuming more grass, because grass has a different photosynthetic pathway than do herbs. And so the signature that ends up in the carbon of the tooth is different.
And so if we look at these blue squares right here, these represent — these are members of Homo, or own genus. And these are hominids that came before Homo. And notice that their signature falls halfway between browsers and grazers and it’s quite similar to obligate carnivores like hyenas and lions and these animals that are now extinct. So animals that eat these other animals, if you’re a lion or a hyena you’re going to eat both a browser and grazer and that’s why they have a mixed signature. And so the interpretation here is that these guys were also eating both plant and animal foods.
So this is the uncertain part of the diet as how much plant and how much animal food were being consumed. And let’s go back to that original diagram and what we can say is starting in about 2.5 million years ago and it’s somewhat coincident with the evolution of our own genus Homo where there’s evidence to show us that we’re starting to eat more and more meat. And I’ll show you that’s probably one of the key environmental factors that allowed for large metabolically active bring to evolve.
So what is that evidence? If we look in the fossil records, stones don’t leave us. Okay, they’re basically here almost forever and these are stone tools that were unearthed in Ethiopia. And this is the guy that actually found them. And if you look carefully up here, you’ll see there’s two types of stone tools. They are the sharp flakes and the sharp flakes is what these guys are really after when they’re making the stone tools. They can be used to disarticulate a carcass and modern-day experiments show that they’re very effective at cutting open skin and getting muscle and bone away from the carcass.
The second part is this core which is results — it was the result in part from this chipping process. And this is effective at smashing open skulls and getting at brain tissue. It’s also effective, if you put it on a animal stone and getting at marrow. So we think that marrow and brains were some of the key dietary factors that allowed us to become human.
This is one of the most cool fossils ever found and this is the jaw bone of either a hartebeest or wildebeest. And if you look up here there’s a little scratch mark and if we magnify it with scanning electron microscopy, there’s a very characteristic mark that is not a [Nam arc] from another carnivore nor is it a stone mark that happened to randomly scratch this while it was being fossilized. So we know that this is indeed a cut mark and it’s on the medial side of the jaw bone, meaning the inside. So what do you think they were after? Yeah, they were after the tongue. And so work from our laboratory shows that the tongue actually is a high source of mono-unsaturated fats which are healthy fats. And the same thing is true with marrow is when they cracked open the marrow they were also abstracting a food that was also very high in monounsaturated fats. So these are very healthy fats in terms of what they do for cardiovascular disease.
Expensive Tissue Hypothesis
Okay. Here’s another very intriguing bit of evidence. This was the so-called Expensive Tissue Hypothesis and this was invented by my colleague Leslie Aiello at the University College in London. And this paper came out in 1995. And if we look at our brain size and we contrast it to our gut size, we have incredibly large brain, and we have a very small gut. If we were to look at all other primates, monkeys and apes and so forth, and we were to predict what a 65-pound or 65 kilo primate ought to look like, we should have a very large gut and we should have a small brain but we don’t. And so the implications of this – there was an evolutionary trade-off to evolve a large brain at the expense of having a reduction in our gut size. And so this is how we interpret this, is if you look at the slide and you envision a brain – “a brain is the hottest organ we have”, metabolically it uses more ATP than any other organ in the body, about 9 times — as you’re at rest right now 9 times the amount energy is devoted to running that brain.
So think about it, if we had a brain that was filled our entire body, my God, our metabolism would be out the roof, wouldn’t it? And so this is the key to understanding this Expensive Tissue Hypothesis is that we actually measured our overall metabolic rate and guess what it turned out to be the same as all other primates. So inferred on that was the notion that another organ’s metabolic rate had to decline and indeed that’s what happened. So we started to have this — we had selection for smaller gut which allowed for the selection of a larger brain.
Well, how did that happen? Remember what the diet of the chimpanzee was primarily fruit and plant-based food. So as we started eating more and more meat in our diet which is more calorically dense, then that was the selective pressure that allowed us to evolve a larger brain.
Origination of Hominids
So here’s some really interesting data. If we look at where all hominids actually originated, they originated in this East African area here, all the way down to South Africa on up to Kenya. And the origin of Homo, our own genus, occurred about 2 million years ago. So this is a very cool fossil that was found 1.65 million years ago. But notice that the first fossil of hominid found in Europe was found in this place site called Dmanisi site in Georgia — present-day Georgia and it’s dated to 1.8 million years ago. So what that tells us is that our own genus somehow had to have gone further north. And so the idea is that we either walked down the Nile and we crossed right up here and then we went up through this Black Sea area. The Black Sea actually didn’t exist then. And this is how we got to 40 degrees north latitude.
Now I don’t know about you folks here in Pensacola but I live in Colorado, right 40 degrees north latitude right now and the ground is still frozen. There’s no food. So you are at 4G, you’ve got to have animal food as a major source in your diet. So the behavioral adaptation to either to hunt or to scrounge animal food had to have happened at lower latitudes before we could have got here. So even during the interglacial periods, you had to have animal foods to live at these very far north latitudes.
Okay. This is some interesting data and this is stuff from our laboratory. If we look at cats, cats are obligate carnivores — meaning that they have to get all of the nutrients that they need for their bodies from their total animal food based diet. And so I don’t want to get into too much into biochemistry but if we look over here at Vitamin A and beta-carotene, just the basic metabolic change that we can do on our liver. If we eat carrots, which have a good source a beta carotene, we can turn them into vitamin A but we don’t do that process very well at all. And vitamin A is absolutely essential for every cell in the body. Cats can’t do it at all. So if you are Linda McCartney and you’re trying to make your cat a vegan vegetarian, you’ll kill it.
So where do you suppose these guys — before we are feeding them cat food, if they can’t convert beta carotene where do they get vitamin A in an animal food? The organs, yes. So liver is a good source of vitamin A. Marrow also has vitamin A in it and believe it or not tongue has vitamin A in it. And so these are the biochemical pathways, if we have any biochemist in the audience, this is the same type of a situation.
So let’s go back to the uncertain – how much plant food and how much animal food were being consumed in their diet? We know that they were eating more and more animal food but what is the percentage? Because this is the evolutionary template that we need to address when we talk about a healthful diet in this modern age. Should we be eating a vegan, vegetarian diet? Should we be eating a high meat diet? What is the evolutionary template – because it provides us insight into how we should be operating now.
So this is a paper we published all the way back in American Journal of Clinical Nutrition in the year 2000, and what I did here is I compiled data from a document called the Ethnographic Atlas. And the Ethnographic Atlas went out and it looked at all the world’s hunter-gatherers. And so in the early days of frontier physicians, there were anthropologists, there were explorers, they went out when they were still hunter-gatherers on the planet and they made notes about what these people were eating, and plant, animal food and so forth. And admittedly this is pretty soft data but it’s some of the only data that still exists. So we went through and compiled it and we published our results. And let me show you what we found with this soft data and then I’ll show you some better data.
So let me walk you through this little frequency histogram right here. And we examined the amount of gathered plant foods in 229 hunter-gatherer societies. And so we broke it into one — we didn’t; this was data that was already pre-existing in the ethnographic atlas. It was broken into one of 10 categories: 0 to 5% plant foods, all the way up to 86% to 100%. And notice, though, the value here in the middle, this represents the Mode which is the most frequently occurring value, 45 societies consumed 26% to 35% of their calories as plant foods. It’s also the Median, the value that falls halfway between one and the other value.
The other point I want to make out is look, there’s not a single vegan vegetarian society in this whole mess. And the reason why there isn’t is because this diet is lethal unless you supplement with vitamin B12. And they didn’t have supplements back then. So and notice here also that only 13.5% of the societies have more than half of their foods from plant foods. So at least this evidence is somewhat supportive of the notion that whenever and wherever possible we would try to consume animal foods.
And so this graph represents the total fished and hunted animal foods in the diet and you’ll notice then that the Mode and the Median right here fall at about 56 to 65. So a little over half to two-thirds of their calories came from animal foods if and when it was possible.
Shortcomings of Ethnographic Data
All right. Take a look at those six pack abs on those guys. So I’ve seen many photographs of hunter-gatherers and this is a fairly typical photograph is this is how they looked. And the problem with the ethnographic data is very subjective. What if it was a man who went out in the field and he was looking at the food that was being brought back in. Maybe that man ignored what the contribution of the female or the children and their grandparents was from the collected foods, they pay more attention to that. So it’s very loose data and what we ended up doing in another paper is we went in, and we found the 13 studies that were quantitative. And these were studies in which they were actually able to measure the foods that were consumed, the total weight, the calories and so forth. And there were 13 of them and we ended up eliminating two of them.
We eliminated the Eskimos right here and notice they are living in Greenland, it’s 69 degrees north latitude and they were eating 96% animal, 4% plant. Well that’s skewed our results because they didn’t have a choice except for a year – a month or two out of the year they couldn’t do it. And the same thing here with the Nunamiut people; once again 99% and 1%. So if we take those two values out, what we see is a similar value, about two-thirds of the energy come from animal foods and about a third from plant. So this corroborates the data that we had from a previous study.
This is my colleague Mike Richards at Oxford and this is one of the most cool fossils found of all time because this fossil we’ve actually sequenced the Neanderthal genome from. So there’s actually a series of fossils but this is one of them. This is the Mandible dated to 29,000 years from a cave in Yugoslavia called Vindija. And we’re looking at another isotope here and the isotope we’re analyzing is delta 15 nitrogen. And what this isotope does is it tells us how much animal food those Neanderthals were eating. And so what we have to do is we contrast that isotope to other animals, to other fossils found alongside that Neanderthal bone. And you can see there’s a Wolf, an Arctic Fox, Bison and Deer and so forth. And carefully look at the signature here. This is the Neanderthal. It has a signature that is virtually identical or higher than a wolf or an arctic fox. So Mike’s point was –is the Neanderthals were clearly behaving as top-level carnivores.
Now Neanderthals aren’t us. That’s another different – there is a same genus but another species. So let’s take a look at Mike’s data from some more modern people. These are fossils that were found in England in a place called Gough’s Cave and there were five Homo sapiens dated to about 12,000 years ago. And what you can see is once again 12,000 years ago they had the signature that was almost identical to this arctic fox, which is not an obligate carnivore but gets most of its calories from animal food. So this data also supports the notion that humans whenever and wherever possible were eating a lot of meat.
Okay. So you don’t have to be a scientist here on this one. This is pretty intuitive. So we know they were eating minimally processed wild plant and animal foods and that should be the template that we use for our modern diet. And so obviously they simply did not have the technology to produce these types of foods.
Okay. So what’s wrong with eating this food versus eating this food? You may not think about it but once again sometime pointing out the obvious is one of the most difficult things to do. You know, the king is not wearing clothes. So this is what we did in a paper published in American Journal of Clinical Nutrition in 2001. And we went in and looked at the disposal data in the United States. It turns out that 70% of our calories come from basically four, five different foods – breads, dairy, refined vegetable oils and sugar. Okay, if you take cereal and combine it with vegetable oil and sugar, you can call it a cookie, you can call it a donut, you can call it a cracker, you can call it whatever you want. But it’s the same combination of all these same ingredients. So these things comprise 70% of the calories in a typical Western diet. We eat the same things day in and day out.
And another way of looking at it is with this pie chart. And I’ve deliberately put this pie chart together to show you the foods in white, these are the recent foods. These foods have all been put into our diet since the industrial era and the Neolithic period. And we will talk about what that is here just shortly. And so these foods are calorically less dense. They have less vitamins, less minerals, less phytochemicals. And they have weird fatty acid profiles. And so by default, if you look up here on that pie, if you put those in, what do they do to the rest of the foods, the real foods, the meets, the fish, fruits and vegetables? They compress it. And so our diet becomes nutritionally less dense. The vitamins and minerals are less when you include these in your diet. So they displaced those foods and it has important health implications.
Evolution of the Western Diet: Neolithic (10,000 to 5,500 yrs ago) Food Introductions
This is the period called the Neolithic and this is the period when we changed as a species from living as hunter-gatherers to becoming farmers. And it is a period that occurred from about 10,000 years ago when the agricultural revolution first began to about 5,500 years ago. And so we first domesticated animals 10,000 years ago. 10,000 years ago, my God that seems so long ago, it’s so historically remote. But on our evolutionary timescale a generation is considered to be 30 years. And that’s only been 313 human generations. So we still have the genetic makeup of stone ages. We’re literally stone-agers living in space age, and we have genes and bodies and digestive systems that are very well adapted to the foods that we have always consumed.
So these recent introductions, here is the first time cereal grains were introduced. Believe it or not, we talk about grains as the staples and staff of life. They’ve only been domesticated in the same timeframe. The first dairying evidence we see from about 9000 years ago but probably people were consuming dairy products once they domesticated these animals. So this just represents a lag in the fossil record.
Okay. Wine and beer, nobody had any find until 6,000-7,000 years ago. Okay, the first salt mines in Europe appeared about a little bit after that, and Sucrose, which is table sugar, was first produced in India about 2500 years ago. But the thing as it was made from cane sugar and it wasn’t exported around the world. So only a few people had it and the rest of the world simply didn’t have it until much later.
Evolution of the Western Diet: Industrial Revolution (~200 yrs ago)
Okay. The Industrial Revolution — this is when things really started to change. And let’s take a look at this. So this is when table sugar, sucrose, became available to the masses, it was starting in about 1798, the turn of the century whenever 200 years ago.
Feedlot produced meats, fatty meats, that never ever happened. We didn’t have the technology to bring cows in and grain to market and produce these fatty meats that are ubiquitous in our diet now.
Refined grains — white bread, white rice, all of these things are technological innovations. We never did these until fairly recent times, and I will show you the technology that allowed for that.
Refined vegetable oils –in all processed foods we put refined vegetable oils but once again you can see a very recent addition to the Western diet. And when you look at it from generational perspective, obviously our genes have not changed in three or four generations. We have the same genes our grandparents or great-grandparents. We have basically the same genes that people had 10,000 years ago. So this is on-slot to our physiology in our health to throw 70% of our calories into our diet in the mere timeframe of four to five human generations.
Hydrogenated vegetable oils, a little bit later still and HFCS — what’s that? High Fructose Corn Syrup. Now when I was as young as some of the people here in this audience, this stuff didn’t exist.
Processed Foods – The 20th Century
Okay. This is kind of fun slide, we’ll just rip through it. But this is when processed and junk food came about. There is Hershey’s Chocolate Bar – 1900. We can hear applause as we hit one of your favorites. Pepsi – 1902. Kellogg’s Corn Flakes – 1906; Crisco 1911; Oreos have been around since 1913. I guarantee it will never ever go away. Wonderbread 1921; Rice Krispies, you know those Rice Krispies treats, could have eaten those before 1928. Corn Chips – 1932; M&M’s, now that’s one that definitely will not go away. Sugar Frosted Flakes and Pringles chips 1969.
Okay. So when we look at these Neolithic and Industrial era food introductions, they caused a lot of problems in our physiology, in our health and our well-being. We identified 7 key characteristics and let me just walk you through these because you may not have a nutritional background.
Neolithic and Industrial Era Foods: Nutritional Implications
But the Glycemic Load is very important. The way a food impacts our blood sugar, we can measure it, and foods that really raise our blood sugar or blood glucose have high glycemic loads. So the white bread right here, these potatoes and this drink all absolutely do a number on our blood glucose. The unfortunate part of this is they also elevate our insulin. Insulin is a master hormone and it causes lots and lots of problems.
Fatty acid balance – the types of fats that are in this hotdog are way different than what we find in the tissue of wild animals. The macronutrient balance – in the Western diet we eat primarily carbohydrates. They are a major source of energy, whereas in Stone Age diets, the predominant energy source was either protein and fat and carbohydrate was always low. And so that’s a characteristic pattern – high-protein low-carbohydrate that we’re finding out now from randomized controlled trials is helpful for humans.
Trace nutrient density – there’s no vitamins and minerals in here and when you consume that, you are displacing real food – fruits and vegetables. Acid/Base Balance – we’ll talk about that in a little bit but if you eat lot of fruits and veggies, you have a net base yielding urine. And Sodium/potassium balance — with salt everything’s we have way more salt than we do potassium. And there’s no fiber left in these things because they’re entirely fiber depleted.
These seven nutritional characteristics wreaked havoc with our body and we can trace them to many many diseases. The symphony orchestra plays not with the single instrument but together. And so all of these factors synergistically impair our health and our well-being.
Okay. Let’s look at these one by one and show you why they were not part of the hunter-gatherer diets. Let’s take a look at cereal grains.
If we look at grains, about a quarter of our calories come from cereal grains. Unfortunately this is the type of cereal grains we eat in America. We eat these refined grains with high glycemic load and that adversely affects our health and well-being.
How do we know that hunter-gatherers didn’t eat cereal grains? Well, first off, cereal grains are the seeds of grasses and in their wild state they’re very small, they’re difficult to harvest and you got to do a lot of things too long to make them edible. You’ve got to grind them up and you’ve got to cook them. Otherwise the starch and the protein is not available to you. So it represents a lot of work and there is a theory called optimal foraging theory in anthropology. And you go out and you’re a forager you’ve got to get more energy from the food than you expend. Okay, if you go out and you hunt and gather all day long, you come back with 50 calories, it’s a bust. So you’ve got to come back, you’ve got to get more energy than what you expend and these foods are rotten at getting energy back because it takes so much energy to collect them and process them and cock them, build the fire and all this, the hunter-gatherers basically ignored this, and viewed them as starvation foods.
So when did we first see these grains being included in our diet? It’s when in the fossil record we see these crude grinding stones. And so this occurred in a culture in the Mideast called the Natufians, roughly 10,000 to 15000 years ago. Up until about 1880 the way we ground our cereal grains up to make our bread and our flour was with the stone grinding tools. This is how it was first done and then later on we built these water wheels that turned these gears that ground the stones together. And when we made our flour everything was mixed together. There’s three parts of a wheat berry – there is the germ, the bran, and the endosperm. And so when we do it like this, everything gets mixed up together and we call that flour 100% extraction flour. So that’s perhaps not unhealthy as white flour, and that’s pretty much how it was done up until about 1880.
And then in 1880 what happened – we invented these things called steel roller mills. If you look up here you can see that we fundamentally have changed the way in which we’re breaking up the wheat berry. Instead of pulverizing it and grinding with these stones, we’re putting it through and squeezing it. And when we squeeze it, a couple things happens is the germ and the bran come off as a nice little flake and we can sieve them out very easily. And then once we sieve them out we don’t stop there. We continue putting the flour through multiple breaks until we get these tiny little particles and that’s what we make our white bread out of.
Now it was done at the time because people liked this nice white flower without any bran or germ in it. But had they known the adverse health effects of doing this, it probably would have never happened.
So here’s what happens to the glycemic index. We talked about glycemic index — the ability of a food to raise our blood sugar. And what you see right here is we start off with the whole wheat kernel 100% extraction where we keep the bran and germ everything intact. It has a low glycemic index and by the time we’re down here to making these fancy flours that we use for all kinds of fancy pastries and whatever, the glycemic index has risen to 70% or 80%. And if you look over here, this is a list of foods. These are common cereal refined grains and you notice almost every single refined grain up here has a high glycemic index, which is defined as greater than 70.
So you think about healthy foods like Cheerios, they’re advertising them as heart healthy. Well I don’t think so, not based on the glycemic index by any means. And so watch some other ones, here people like Bagels you can see Bagels are typically high glycemic load foods.
All right. What’s wrong with the higher glycemic load carbohydrate is that if you eat these things over the course of your life time, they tend to promote a condition called the metabolic syndrome, which is when our body becomes resistant to insulin. And when the body becomes resistant to insulin, what happens is the pancreas secretes more of it. So the muscles say, “Hey, I’m full. I don’t need any more foods. I’m done. Don’t give me any more insulin”. So what the body does is it sacrifices the insulin for the blood glucose. To keep blood glucose low, it secretes more and more and more insulin. So we have this chronic state of high insulin, and that’s associated with all of these diseases that you see here — type 2 diabetes, hypertension, heart disease. You go down to your cardiologists, your physician get your blood chemistry measured. I’m sure most of you’ve had that done. And this is what they’re measuring – the values that they measure and what we see with the metabolic syndrome is a very characteristic reduction of HDL, which is the good cholesterol, we have blood triglycerides elevated, and we have LDL weight which has increased.
Okay. Something that even if you’re involved in nutrition, you may have never heard of it is the concept of acid-base balance. And if we look at all foods, they report ultimately to the kidney as either acid or base. And so you can see all grains are net acid yield — all the ones in red are acid yielding foods. And notice that cheeses paradoxically are almost an order of magnitude higher in their acid yielding than any other food. So I will show you that the problem is net acid yielding foods tend to promote osteoporosis. The only base yielding foods are fruits and veggies. And we don’t eat very much of these in our diet.
And so consequently the Western diet is net acid yielding and this is how it works out. You can see that grains provide a quarter of the energy – they’re acid yielding meats or acid yielding cheeses except for milk which is about neutral or acid yielding. And salt of all things yields acid ions to our kidney, and we eat very little fruits and vegetables. Less than 10% of our calories in the U.S. diet comes from fruits and veggies. It’s almost guaranteed that if you do this over a lifetime both men and women will become osteoporotic.
So what are the diseases associated with a diet that is net acid yielding – osteoporosis, high blood pressure, kidney stones and stroke. So this is how we eat. We consume these foods and if you look up here you have trouble seeing any fruits and vegetables. Here is some parsley and – I don’t know what — maybe a slice of tomato over there.
What happens to refined grains? What happens to the vitamin content after refined grains? Well you can see this right here. Whole wheat, you can see, has much greater concentrations of almost all of these vitamins. And you can see what happens here to all these other vitamins. We started to enrich our flour after World War Two with these three B vitamins and iron and I will show you that here in a minute. And then since 1998, we put folic acid, not folate back into our diet and it’s turning out that that’s probably not a very good idea. It’s increasing our risk for prostate cancer. It reduces the risk of neural tube defects in infants but it’s kind of appeared victory. It’s a trade-off, it doesn’t seem to work very well.
Well let me go back one other point. So when you take out all the vitamin B6 and you take out all the Folate, this increases a chemical in our blood called homocysteine which irritates the lining of our arteries and promotes cardiovascular disease. This is what happens to the mineral concentration of flour and you can see all the minerals get knocked out completely and there’s a whole bunch of diseases associated with it. The calcium that’s available in whole grains is bound to a compound called phytic acid or phytase. So we actually don’t get any of this calcium anyway. And these are some of the diseases associated with poor calcium intake.
Now if you decide to do the Paleo diet and you go to your physician or your nutritionist, you say, look, I’m going to cut grains — whole grains out of my diet. But oh, my God where you’re going to get your fiber. You’re going to have no fiber, you’re going to be constipated for rest of your life. That’s not true.
If we look at whole grains and we contrast the fiber content to a 1000 kilocalorie sample, notice that we have almost twice as much fiber in fruits and non-starchy — and non-starchy vegetable is completely off the roof here. So this is a myth and fiber has important effects on our health, particularly the types of fiber that are in fruits and non-starchy vegetables are soluble fiber versus the insoluble fiber in whole grains except for oats which has a little bit of soluble fiber. And so there’s the laundry list of diseases for the gastroenterologists in the crowd. And some of these aren’t completely bought into. So some of these have changed a little bit.
How do we know our ancestral diet — we didn’t have dairy products? So take a look up here. Look at this, you know anybody ever tried to walk up to a wild animal? How about doing this to it? It’s just not going to happen. See, you have to domesticate an animal before you can knock it. And so people simply couldn’t have had dairy products in their diet until we domesticated animals.
This is how the numbers come in for dairy products. You can see we eat about 10% of our calories as dairy and this is how it mixes up. And so we’ve already seen this slide. This is when we first find evidence of dairying about 9,000 years ago.
And what’s the problem with dairy products? They have a really weird fatty acid balance. All foods — fatty foods or animal foods are mixture of poly-unsaturates, mono unsaturates and saturated. But you can see here if we look at wild animal tissue, we have a pretty good mix between mono-unsaturates and poly-unsaturates, and we have a lesser amount of saturated here. But we have very very good mix.
Whereas with dairy products, you can see we have low levels of poly-unsaturates and very very high level. And so if you include a lot of fatty dairy foods, it tends to imbalance fatty acid and tends to promote some diseases.
Now I kind of reversed my position a little bit on the saturated fat thing and I think most of the world has started to see a little bit different perspective. So in terms of increasing the risk for heart disease, it does but it depends on what you replace saturated fats with. If you replace saturated fats with carbohydrate, you’re in worse shape than starting off with saturated fats. That’s what the most recent information shows. So what we ought to be doing is replacing saturated fats with what we had in our diet originally – mono-unsaturates and poly-unsaturates. This is a very healthy profile.
Okay. So if you look at dairy products and we talked about the glycemic index and how that promotes many many diseases, you’ll notice that refined grains have really high glycemic indices. But come down here, look at milk and yogurt, my god, look at how low they are 27-24. At least in theory they ought to be healthy foods. But work from our laboratory — right here this is one of my graduate students Gerhard Hoyt turned out differently and what we found is that they knocked our insulin levels sky-high. It’s just like eating cookies.
So let’s take a look at that data. And you can see here that all dairy product have very very low glycemic index. That means they don’t jack our sugar levels up. But paradoxically look compared to white bread, yogurt has an insulin index that’s even higher. So all of these dairy products have these enormously high insulin index. And there is at least one experiment in children showing that this produces insulin resistance. A high dairy product or high dairy diet for only one-week caused insulin resistance in children. That experiment hasn’t been repeated yet in adults and that’s what we want to do in our laboratory.
Okay. So another thing is they really didn’t eat fatty meats. All right. They eat everything, they eat the entire carcass. But while animals don’t have a whole lot of fat on and let’s take a look at that data.
Fatty Meats: Year Round Staples in Western Diets
So here’s the staples in the American die. This isn’t meat, this is fat disguised as meat. And when you look at the percentage of fat and protein, what we really need to look at it is not a percent by weight but percent by energy, because at the end of the day we eat calories, we don’t eat weight. And so when we look at these values by energy, you can really see that these types — look at hot dogs, my god, it’s 82% fat, 14% protein. So these are very very unnaturals compared and I’ll show you some really good photos.
If you look at body fat in wild animals, it waxes and wanes seasonally. And so once we invented agriculture, what we could do s we could feed fodder to our animals and we could prevent this seasonal loss in body fat and we were stupid enough to slaughter them when they were all leaned out. We slaughtered our animals when they were the fattest. So that changed things considerably.
Whereas when we were hunter-gatherers, we were at the mercy of the seasons. We got whatever fat the animals had on them. And so this is a slide that shows you how the body fat – this is body fat percentage on the Y-axis here. You can see how it changes month by month and in North America, the fat in North American animals peaks just after summer and then it falls again as we move into winter.
And if we look at that data and we combine it all, I point this out to you is that the average body fat in these wild animals over seven months is about 3% from January until July, it’s about 3%. And then it goes up but over the course of the entire year the average body fat is only about 7%. I bring this data because I want to show you what we have in animals that have been raised in feedlots. You don’t need to look at us — a graph. Look at the difference here. I mean and these guys have already been trimmed. They’ve trimmed probably 4, 5 inches of subcutaneous fat after they hang them. So most the fat has been trimmed off but look at them compared to a wild animal. There’s absolutely no comparison and look at the meat. There’s no marbling here on wild animal meat versus what we see over here. So we slaughter cows at 30% — 25% to 30% fat. Look at that, that’s 10 times more than wild animals have.
So other issues with the fat comparisons between wild and domesticated animals are the omega 3 fats. And notice them, this is work from our laboratory showing that wild animals elk deer and antelope have much higher concentrations of this helpful omega 3s. Now the crucial take on point here is if you can get it, yes, pasture fed or grass-fed beef is considerably healthier, you can get wild meat better still.
How about salt? Salt is an additive that we all put in our diet. We don’t even know it, we eat about 10 grams of salt on a daily basis and most of it comes from processed foods. If you eat bread, you’re getting salt. A slice of bread has about 1.5 grams of salt in it. So you don’t think about bread as a salty food but indeed it is. So most of it comes from the processed foods that we consume.
When did we start including salt in our diet? That’s tough to pinpoint because we live near the oceans, or coastal areas and there is no doubt that people probably dip their food in salt. But inland Europe and other places the evidence tells us that people really were interested in salt. This is an entire mountain of salt in Spain. By the way I spoke in Spain two years ago and I threw this slide up there. People on the isle saw — I know what that is. So I just downloaded this but this is an entire mountain of salt and the tools that were used to dig the salt out were dated to this time. So people pretty much were interested in it.
Okay. How about refined sugars? We eat almost 20% of our calories depending on whose data you’re looking at – 15% to 20% of our calories as refined sugars and we’ll see what’s wrong with that. Hunter-gatherers absolutely no doubt would have consumed honey whenever and wherever they could possibly get it. I’ve got a colleague Kim Hill at the University of New Mexico, now at the University of Arizona. He spent his entire career studying the Ache people in Paraguay and he tells me that he has seen a male Paraguay standing up a tree, or Ache standing up a tree, grab honey out of the wild bee hive and throw it down to his colleagues on the ground. And honey comes with the comb, the larva, everything. And he says he saw a guy like 5 pounds in this comb, larva and honey. And his stomach went like this. So they do it occasionally but they certainly don’t do it on a daily basis because honey certainly is not available day to day.
This is a per capita disposal data of refined sugars from the Netherlands. And notice that the average citizen until the Industrial Revolution didn’t need very much sugar at all. And then from about 1800 and till 1940 we got up to over a hundred pounds per capita. We see similar figures in England through that same period and notice the two dips during the world wars when sugar was rationed.
So this is an interesting phenomenon, I will get to it right here in a minute. We get to about 120 pounds per capita and this is sucrose or table sugar. So that’s about the only sugar we were eating up until 1970s. This is data in the US for all sugars. We peaked in the year 2000 — we went up 64% increase from 1909 up to 2,000 and then for the first time in the last decade we went down just a little bit. So we’re doing a little bit better. And this is all sugars but I will show you the problem in the next slide.
Changes in the Refined Sugar Composition in the U.S. Diet Since 1970
Starting in about 1970, we were able to take corn starch and turned it into fructose for the very first time economically through a process called chromatographic enrichment. And we could do this economically, so we didn’t have to put a lot of energy into it. It’s kind of like a filter and it allowed us for the very first time to make high fructose corn syrup.
Fructose is about 50% sweeter than sucrose. So if you’re a soda pop manufacturer, that means you don’t have to put as much into your soda pop, so you can sell your soda pop cheaper. So it was entirely financial why we changed from sucrose to fructose.
And this is data from our group in tracking the infusion of High Fructose Corn Syrup into the US diet. Now when I was in my prime, we didn’t get any of this stuff in our diet because it didn’t exist. And then by the next decade by 1980 you can see we slipped a little bit more in and by 2000 we almost had as much high fructose corn syrup in our diet as we did sucrose. And now we’ve done a little bit better in the next decade because I think there is political fallout from high-fructose corn syrup now — at least not so much with the manufacturers but with the people and the consumers.
So what are the diseases associated with the refined sugars? Name a disease that isn’t — but in particular I haven’t listed the type — the epithelial cell cancers, breast, colon and prostate are all associated with high dietary sugars.
Okay. The last slide, I mean we’re going to finish up here shortly and then we will open it up for question and answer — just a few more slides.
Refined Vegetable Oils
Vegetable oils — refined vegetable oils in the diet. About 20% of calories and here’s where they come from –shortening, margarine, salad oils and cooking oils. Prior to the Industrial Revolution and actually the last 100 years there is really only one way of making vegetable oils. It was with rendering and pressing. So like with olives, they shredded the flesh from the olive and then they put it in primitive wooden presses and they pressed the oil out. And that was one of the few vegetable oils that humans consumed until the last 100 years or so.
The other way of making vegetable oils out of plant foods is with steel expellers and that process only happened in the last 100-120 years, and solvents is even more recent still. So let’s take a look here. This is one of these portable steel expellers and using this machine we can get oil out everything. You know when you think about sweet corn on the cob, you don’t think about it as oily vegetable, do you? Absolutely not. So you can take that and you can squeeze it with enough pressure and you can get vegetable oil out of it.
We figured out this hydrogenation process in 1897 we could turn vegetable oils into solid margarine and shortening and that yielded these novel trans-fatty acids which we know now are very detrimental to human health. We ate those for 70 or 80 years before we figured that one out.
And this is the data showing how we’ve increased the vegetable oil consumption since 1909. We’ve had a 500% increase since this time frame. Now my grandfather came out to the West Coast. He came out to Hollywood back in the 1920s and he established a restaurant in Hollywood. And his restaurant served probably between 100 and 200 people at any given time. And so after he died, all of his stuff went to my mom. And after she died, I got all of that. And I remember about 10 years ago thumbing through one of the books that I had inherited and it was a cookbook from my grandfather’s restaurant showing how to make recipes for large groups people. And as I thumbed through it and the book was printed in 1913 I believe – as I thumbed through it, there wasn’t a single recipe that used vegetable oils. There was a little, I think olive oil in one or two but other than that they simply didn’t use vegetable oils.
So in the mere frame of three or four human generations or less, we now have seen this kind of incredible data. And what’s wrong with it is that vegetable oils are loaded up with a fat called linoleic acid and have very low alpha-linolenic acid — meaning that they are high in omega 6s and low in omega 3s. And we know omega 6 fatty acids tend to be pro-inflammatory and are associated with any disease that has an “itis” on it, such as hypertension, autoimmune, gout, obesity, cardiovascular disease and whatever. So these are the good things to get out of our diet and go back to more traditional oils like vegetable oil.
So this is — I had a little bit of fun playing around with the USDA Food Pyramid and chopping it up. It’s now called My Pyramid. And so we’ve eliminated this. We’ve eliminated this. And actually if you look carefully down here I think there’s some peanuts which are legumes, they are not part of the deal either. So eggs and meat and fish and poultry are great and fruits and veggies.
So this is what I recommend for a modern-day healthy Paleo Diet is you’re 85% of the way there if you do your shopping in the outside aisles in the supermarket. You can get everything you need from fruits, veggies, meats, seafood, healthy oils, nuts and seeds. As a matter fact, the diet is much more nutritionally dense when you follow these types of advice. So thank you very much.
Okay. So we’re going to open it for questions.
Male Audience: Thank you for a wonderful a lecture. Before the lecture we spoke for a few minutes about inflammation being a key in America. Speak more about inflammation and nutrition, if you will, please?
Dr. Loren Cordain: Yeah. I think that if we look at all the chronic disease in the Western world, what we’re really looking at is chronic low-level inflammation. You can have heart disease, you can have cancer and you can have autoimmune disease; you have to have inflammation to drive the process. So the process can be initiated without through other means but to keep it going you have to have inflammation. And what we believe is that the gut, the intestinal interface is one of the major areas where chronic low-level inflammation occurs. So we have an area in our intestines that’s roughly two football fields in square area, and we’re exposed on a daily basis to more antigen, to more viruses and microorganisms in this area than any place. We get a cut — we get a little bit in our mouth but not even close to the surface area in our gut.
And so there are two types of bacteria in the gut – there is gram-positive and gram-negative bacteria. And gram-negative bacteria in their cell wall contain a substance called LPS or Lipopolysaccharide and Lipopolysaccharide is a very potent proinflammatory compound. And normally that compound in a healthy gut stays in the gut and doesn’t leak into our immune system and our circulatory system. I’ve got a colleague [Patrice Connie] in Belgium and this is what his group is doing is that they have developed a procedure to measure LPS in plasma and showing that it is proinflammatory. And the series of papers that have come out in the last five years are showing that there is a relationship between LPS and cardiovascular mortality as well as cancer mortality and type 2 diabetes. So inflammation is part of the Western diet. If you eat wheat, you’re probably going to — many people in this room with most people do — celiac disease you’re going to probably have a slight low-level inflammation and we can measure it with what are called proinflammatory cytokines. And there are ways of doing it but yes, inflammation is huge. And elements in the Western diet — cereal grains, legumes tend to be proinflammatory as do high glycemic load carbohydrates.
Male Audience2: Thank you for coming here. One of the things I did not notice here and what I’ve seen in my 30 years of practice is that we used to have conferences because we saw fatty liver and I would give a grand rounds of talk about it. Today I’ll see four to six people in a day with cirrhosis and liver disease now in this country, the leading source is probably from obesity for cirrhosis, not alcohol. This entire lecture is all linked to that. And I wonder if you go ahead and expand on that.
Dr. Loren Cordain: Yeah, you know the notion that we talk about high fructose corn syrup and many nutritionists as well as biochemists realize that fructose is handled completely differently in our liver than other refined sugars. And so what happens with fructose, there is a step in metabolism called the phosphofructokinase step. And what that step does is it regulates the flux of sugars through the liver. And fructose is a very weird sugar is that it bypasses this, it’s kind of a gatekeeper; think about it’s a waterwheel and it’s got this little guy on that is preventing unlimited flow through that system. And so fructose enters beyond that gatekeeper step and fructose then in the liver serves as a substrate to build fat. And so the liver actually builds fat, there’s something called acetyl-coenzyme A and another factor — you don’t need to know the biochemistry – and that promotes the synthesis of fat in the liver. And so it’s not surprising because that pathway exists that we find this.
Now on an evolutionary scale, why should we have that pathway? That makes a lot of sense. If you’re a chimpanzee and you’re living out here in East Africa and fruit is only available seasonally, what you want to do is you want to turn it into fat immediately. You want to store, so when the fruit is ripe, you want to be able to metabolically store those calories. You don’t want just to come through your body. So on a evolutionary perspective, it makes sense to have that. But when we have unlimited high fructose corn syrup, no exercise on top of a high glycemic load, it is just pouring gasoline on to the fire.
Male Audience3: I didn’t see anything mention about the effects of all these diets on your teeth and how that might influence cavities and plaque formation and stuff like that?
Dr. Loren Cordain: That’s a very good question, is that teeth are remarkably preserved in the fossil record. And what we find is we can go backwards in time and look at dental caries and prior to the agricultural revolution, in the course of a lifetime if you pulled somebody’s teeth out of their mouth, the incidents of caries are like you got 32 teeth, maybe one tooth, two max might have caries in it. It’s usually because of not the type the way caries are formed today but because there has been physical damage to the enamel. But there is very very low incidents of caries in living hunter-gatherers. They don’t have toothbrushes and they didn’t have dentists. Okay, they didn’t floss either. They did do a little bit of flossing, they got things out of their teeth. But there was no hygiene like what we do now.
So the big caries source happened and you can go back in the historical literature is right at the industrial revolution is that there was no such thing really as dentists. That wasn’t a profession, and toothbrushes were not pervasive in the society. So we don’t see it until literally the industrial revolution with the advent of sucrose. And what sucrose does is it encourages the growth of a specific type of bacteria in our teeth, and the acid from their metabolism erodes the enamel and that’s what causes caries for the most part.
Male Audience4: Yes. Is honey any better than sugar? And also is olive oil any better than any other oil?
Dr. Loren Cordain: Is honey any better than sugar? No, honey is a mixture of glucose and fructose. High fructose corn syrup, guess what, it’s a mixture of glucose and fructose. So honey metabolically does the same thing to our bodies as high fructose corn syrup. It’s not – sucrose, on the other hand, is a compound. All right, it’s disaccharide and we have enzymes in our gut that have to break that compound down. So it’s released more slowly. So honey is not a good thing. And what was the question about olive oil?
Yeah, I think olive oil is a very healthy oil. It’s a mono-unsaturated, meaning it is stable during cooking. So it doesn’t break down. It tastes great and it’s got the approval of 5000 or 6000 years worth of testing on it. So I think olive oil is a great oil. The only downside of olive oil is that it is fairly low in omega 3s and fairly high in omega 6s but if you include fatty fish in your diet or your supplement it’s not a problem. So olive oil is — I would encourage you to — an extra virgin olive oil is actually better because it contains more polyphenolic compounds that are anti-cancer.
Female Audience1: I’m confused. I am the daughter of someone who took her degree many many years ago in nutrition. I always thought that if you had carefully made cheese, cottage cheese, milk, those things, it would help prevent osteoporosis. And I think what I heard today was — it’s just the opposite. So I’m confused.
Dr. Loren Cordain: Well, I would say that cheeses are probably not a good thing to do to prevent osteoporosis. And you saw my slide up here when we looked at the acid-base balance. They have almost an order of magnitude greater acid load than milk. Now milk is neutral. But let’s once again look at the evolutionary evidence. We’ve been on this planet for 2.5 million years. We’ve been only drinking milk for less than 10,000 — less than 300 human generations. How in the world do all the other animals on the planet, including all the other primates built bones without milk? There is no single animal on the planet that drinks the milk of another species. So the answer to that comes into — it’s like a bank account. All right, when we look at bone metabolism, we focus upon what the dairy industry, the milk moustache people want us to focus upon is that it’s all about calcium coming into your body. But what you do is when you send your kid off to college to get their degree in nutrition and you give them their checking account for the first time. You say it’s all about how much money comes in, now it’s all about balance. Isn’t it?
So it’s the difference between the calcium coming in and the calcium going out. Any good accountant you have to look at the difference between what comes in and what goes out. And so that’s the important issue is calcium balance. And when we talk about acid-base balance is — the primary mechanism by which we lose calcium is this acid-base balance. So if you don’t eat fruits and vegetables which we don’t, we only get less than 10% of our calories in fruits and vegetables, where all have a slight metabolic acid doses. So the solution – it had to have been — that evolution worked out was that yes, we can build strong bones. How do you think elephants in the jungle build these gigantic bones? They don’t drink milk is that we have these physiologic mechanisms in play and the bones are like any other organism is that they operate well under the environment in which they were selected. And so we have completely disrupted that environment. We eat 10 grams of salt a day. Salt has been shown to promote osteoporosis. If all you do is take salt out of the diet of women and you put them on a DEXA scan, what we’ve found is after a two-year trial their bone mineral density improved, just by getting salt out of their diet.
Female Audience1: So if you are a cheese addict, you eat a lot of — you drink wine and eat a lot of fruit with it, that balances that out –
Dr. Loren Cordain: There you go. Perfect. All right. I can go for that.
Dr. Loren Cordain: Yes. I do. I think that people eat for many many reasons. And I think that we need sustainable issues as well. But I had lunch with some very interesting people today and we were talking about that very same idea. And there is evidence to suggest that a soybean field that is 5000 acres does more damage to the environment. What we’re doing is we’re trading oil for soy. And would you rather trade grass for high-level protein? And so we’ve invented this wonderful machine, we call it cow. And the cow takes grass that we can’t eat and turn it into something we can. So when we make a field of soybeans, we’re taking oil from the Middle East and fertilizing it to make a food that is potentially damaging. So I think that some of these issues clearly aren’t clear-cut. I respect anybody who has religious beliefs or ethical beliefs for not eating animals; that’s fine. But I can guarantee that you’re misguided if you’re eating a vegetarian diet for health reasons.
Female Audience: [Question Inaudible]
Dr. Loren Cordain: You know I’m writing my fifth book right now, and writing a book is as painful probably as it is for women to give birth. I hate it. But I’m happy to get what I say. And I got a chapter – I’ve got a chapter in there on artificial sweeteners and the FDA – Food and Drug Administration – has sanctioned five different sugars. But to my way of thinking they controversial, it’s not as if all the animal studies show that they’re safe. The animal studies can go either way. The epidemiologic studies, the population wise studies generally show them to be safe but to my way of thinking it’s once again the evolutionary template tells us that if you want something sweet, you get a piece of fruit or something or vegetables or whatever. But I don’t know — I don’t claim to know everything about nutrition and the [gylatile] issue. I’ve heard a little but there’s pros and cons to it. But my feeling is that particularly aspartame is that’s a nasty substance. And aspartame, you ought to get out of your diet because I think that there is significant information, a paper just came out this year in the American Journal of Clinical Nutrition and it showed that the risk of preterm birth in women who are taking a lot of aspartame goes about 3-fold higher so that kind of information is not tested early on and we find out after the fact that we shouldn’t be doing these things. So it’s kind of like introducing high fructose corn syrup — what a bad idea but we can’t – it’s very difficult to go backwards in time. It’s like cigarette smoking. You know you’re never going to get rid of it. You need to educate people. So I think that that’s the issue is education rather than legislation.
Male Audience: Thank you. Very good presentation. For the last 10 or 15 years, I’ve been trying to do what I call a caveman diet without this much information. So I like it a lot. And I’m convinced the beer is on the caveman diet. But my question is – why don’t Eskimos get scurvy?
Dr. Loren Cordain: That’s a good question. And it’s because the word ‘Eskimo’ actually means raw fish eater. Okay. So in the Aleut language that’s what it means. And if you think about it, when you eat a vegetable, you have vitamin C in all of your tissue right now. And so when you eat meat raw, it has just enough vitamin C or fish in it to prevent scurvy. So they’re getting probably less than 30 milligrams a day, but that’s enough to prevent scurvy. So that’s how it works.
And you know what, one other thing along the same lines and I know Ken wants to call this – but have you ever thought about you — anybody here that is into exercise or fitness, you realize that when you go into a running race, you want to — many people carbohydrate low, don’t they? — yes so we’re getting all this glucose into our muscles and glycogen – glycogen is a form of glucose that we store in our muscles. And so we have sugar in our muscles. Well when you go down to the supermarket, you buy a piece of meat, what happens to the glucose or the glycogen that was in your muscles and the cow – because the cow has the same thing. Anybody have any idea? So well, the physicians here in the crew ought to know. What happens to somebody when they die, what happens to their muscles? Rigor mortis sets in, doesn’t it? And what drives rigor mortis and allows the muscles to contract after death is the residual glycogen. And then when the glycogen is spent, muscles relax. And so that’s why if you eat a cow, or an animal immediately after you slaughter it, you have a little bit of glycogen in it. But once rigor mortis is done, there’s no carbohydrate or glycogen in the meat.
So thank you very much. I have enjoyed it, Pensacola.