Origins and Evolution of the Western Diet - The Paleo Diet - Part 1

morning so it's a real pleasure to be able to speak to this group I've had a lot of admiration for dr. Vazquez and his staff for putting together a world conference like this it's a real pleasure for me just to be able to walk into it and do my thing so Alex thank you so much okay let's go ahead and get started the talk I'm going to be giving is based on a paper our research group published in 2005 and to say the least I've got a little bit of mileage out of this paper I've been all over the world and it's a topic that I think many people are very much interested in so any time we're talking about the origins and evolution of the Western diet what we're really talking about are the origins of humanity itself and what I'd like to do is walk you through this slide and talk about some of the key points here so the first notion that I want to bring up is the idea of what is a hominin a hominin is a bipedal ape or an ape that walks upright and if we look at the archaeologic record the bones themselves what we find is there's perhaps 22 or even more species of hominids that have existed since the divergence of hominins with apes and so if you look down here the way this chart is set up is that this is the time frame in millions of years and the earliest hominins and these may have been pong kids or Apes appear in the fossil record between five and six million years ago and some mitochondrial DNA evidence as well as nuclear DNA evidence supports the archaeologic evidence that that was a split between pong kids Apes that walked on all fours versus ourselves that walk on on too and so as you move through this there's a couple of key points here this is a period called the Pliocene and the Pliocene started about five million years ago ended about 1.7 million years ago and this is really when a lot of the action occur when we have all the speciation and so each one of these rectangular boxes represents a species of hominins and as we move from the green the lower right-hand corner up to the very top here's our own species Homo sapiens which appear in the archaeologic record about 200 thousand years ago and that's corroborated by the mitochondrial DNA evidence as well as the nuclear DNA evidence we are the only living hominids and the action really got going and this is what we'll be talking about in the next hour so the action really got going from the Pleistocene onward and that's when the very first members of our genus Homo appeared so let's take a look and see what we owe one other final point there was no universal quote/unquote Paleo diet okay so there was all kinds of variations of this dependent upon the species their ecological niche the season of the year geographic location everything and so I think that kind of enters into the equation with modern-day paleo diets is there's really no single version of this alright so what did we know about that plyo Pleistocene period what were they eating we know that all species of hominids were eating both plants and animals so they had an omnivorous diet and this is kind of a cool slide in that the photographs that were taken here were taken in the late 60s and early 70s by an anthropologist by the name of richard lee in botswana and so here we have a woman and you can see these are the fruits of her gathering and if you look carefully you'll see what looks like kind of a modern-day watermelon except it's about the size of her fist that's called a tama melon and over here are some roots and if you look carefully this is the digging stick that she used to dig those roots up here's some groovy berries and right here in the middle for those folks up front you can see this is a tortoise so she got both plant and animal foods when she was out hunter gatherer and of course the men are sitting in the background doing absolutely nothing while she brings home the the food um this photograph is kind of interesting because what Richard Lee wanted to do he wanted to see if these Kuhn people could actually butcher an antelope with a stone tool so if you look carefully a hand axe that was built these things were made starting about 1.5 million years ago they wanted to see if they could actually book butcher it and indeed they could so what are some other evidence to show that all of the hominid species that we looked at on that second slide that they were omnivorous we could look at the diet of our closest living ancestors Jim pansy and this is a photograph Richard Wrangham at Harvard gave me and you can see here that there's two male chimps and they're actually they've killed antelope and they are dis articulating it with their hands so it's real difficult because they don't have large carne seal teeth to tear it up like a big cat so they have to do it with their hands and it takes them quite a while to ultimately eat everything and they they do go into the the skull and they put their fingers through the foramen magnum and pull out brains and eat those which I will show you here maybe later in this lecture how eating brains might be have been a good thing so about 65 grams of meat a day during the dry season so what are some other evidence to show that all of these hominids were omnivorous this is a stable isotope data from Julia Lee Thorpe and mats pon himer he's at CU she's at the University of South Africa and what this is it's a measurement of an isotope called Delta 13 carbon and you can see right here we have more c3 these are c3 plants and what what c3 plants are they're their herbs and shrubs and leaves and berries and so forth whereas c4 plants are basically grasses and sedges and so if you look at the isotopic signature of a grazer or an animal that eats grass you can see it has more c3 so it has less negative Delta 13 carbon signature and so this is what we see if we look at a browser an antelope or an animal that consumes leaves and berries and fruits and whatever it leaves this signature now what I want you to look at is look at the signature of an obligate carnivore here's a leopard right here and here's an extinct saber-tooth cat and so notice that they have a mixed signal and the reason that they well they don't eat any plant foods at all the reason that they have that mixed signal is because they're eating the flesh of animals that are either grazers or browsers and so if we look at the early hominins if you look at Homo in pre anthropos and Australopithecus which are these blue ones you can see that they also have a mixed signal as well so no living ape eats grasses and they're into Jesta becuase they contain high amounts of cellulose and we don't have the enzyme no mammal has the enzyme cellulase to break down cellulose so the way that you can break cellulose down is by evolving a large hindgut where you can ferment the cellulose we don't do that know primates do that except for well there's one there's a baboon over here that does it and you can see this is this baboon right here they're open thickest so it's the only one that does it and it ferments that the grasses and the hindgut so I just published a paper and maybe some of you have seen it the prettiest seedings of the National Academy in which we actually rebutted the popular press suggesting that grain eating had been done millions of years ago it wasn't and this is the evidence for it so the uncertain this is what comes up during that plyo Pleistocene period is how much plant food and how much animal food or all those 20 species consuming well I really don't have a good data set to say one way or the other one thing that we can say is started in about two and a half million years ago maybe even earlier maybe even three and a half million years ago they were consuming more and more animal foods in their diet so let's see what that evidence is starting at about 2.5 million years ago we see the very first lithic technology and this is called the old doll and tool tradition and it appears in East Africa Ethiopia about 2.5 2.6 million years ago and ther
e are two parts to these tools if you look carefully this fellow up here that's actually dr. saman and he was the discoverer of these tools and he's the guy that dated them there's two parts to them there's a core and those sharp flakes and so you can see those sharp flakes and modern-day experiments have shown that these are very these flakes are very effective at dis articulating and butchering large animals and the core can be used to crack open the skull and get it brains and as I mentioned brains are a very good source of arachidonic acid and DHA and so nervous tissue and brain requires a source of AAA or DHA to be healthy and to actually synthesize nervous tissue and then you can see here the the core can also be put on a hammerstone and crack open marrow marrow doesn't have very many long-chain fatty acids but it's got a ton of triglyceride in the form of monounsaturated fats kind of like nuts or olive oil so in the archaeologic record this is what we call a smoking gun and this paper was published in science in 1999 and if you look carefully let's take a look over here on the left-hand side of the slide and you can see there's a scratch mark on the medial surface of the jaw and if we magnify that and then actually look at they scratch through scanning electron microscopy what appears is not just a random scratch but deliberate cut and we know this wasn't made by 9 of carnivores or random rocks rolling around with a fossil in a creek bed because it leaves a very distinctive cut and so what they were interested in doing if this is the medial surface of the jaw what what organ you think they were going after tongue yeah exactly they were going after the tongue and so our group actually have gone in and looked at the fatty acid composition of the tongue in wild animals and it turns out the tongue is also high in monounsaturated fats like marrow and for modern humans monounsaturated fat from animals tastes good so Plains Indians like to make their pemmican out of marrow rather than storage fat because it has more monounsaturated fats and it tastes better to us and over here you can see that these percussion marks showing that they extracted marrow from these long bones okay there's a also additional evidence to suggest that during that plyo Pleistocene period our ancient ancestors were consuming more and more animal food and this is called the expensive tissue hypothesis put forth first by Leslie Aiello in 1995 and if we look at the brain size of modern humans we have these huge brains yet we have a gut that is much smaller than what would be expected for an equivalent 60 kilo primate and so that's really the the essence of this idea is that brain is the most metabolically active tissue in our entire bodies and it takes up about nine times more watts of energy as we're just sitting here than any other organ combined so 9 times more energy is devoted to driving the brain yeah and so if our bodies were all brain our entire bodies were brain think about what our metabolic rate would be would be absolutely enormous so as we evolved a large brain then the expectation would be that the overall metabolic rate would be greater than what would be expected for a primate but it turns out that wasn't true is the overall metabolic rate was exactly as predicted and so then what happened as we evolved a large brain our guts trench and so what is the interpretation of that is that when we're eating a diet more like our chimp ancestors primarily a fruit it took a very large metabolically active gut to digest all of that fiber and once we started shifting over to eating more and more calorically dense fats and brains and meat then it allowed for the selection of a smaller gut because there isn't absolutely no negative selective pressures with doing that there's other evidence as well to show that we are consuming more and more meat in our diet and one of that is the very first members of our genus Homo appear in Africa roughly 2 million years ago and they made it all the way up to 40 degrees north latitude by at least 1.8 million years ago and I come from Colorado and we're at about 40 degrees north latitude we're also a little bit higher elevation but starting in around November the ground is frozen and there's virtually no plant foods that are available and hunter gathers don't store things so what that means is they had to develop the behavior to eat and kill and scavenge animal food at the lower latitudes so that's also suggestive that making it up to this high latitude even during the interglacial periods when europe and asia or warm they still had cold seasons so it is also indicative they are eating more and more animal foods this is an idea that our group had came up with in 2002 and we contrasted the metabolism of cats which are obligate carnivores to humans and cats have made a number of evolutionary adaptations to their all-meat diet and first off cats can't synthesize touring it's conditionally essential amino acid that all cells have to have for optimal function and so cats simply can't do it they've lost there's a an enzyme that the liver makes that allows it to take precursor amino acids and turn them into taurine and so cats have got a a defect in the gene that builds that enzyme and they can't do it but there's absolutely no consequences so they still have very high taurine levels taurine is only found in animal foods it's not found in plant foods so where did they get it they got it preformed you eat animal foods you lose the ability to make taurine humans if we feed infants formula which we did back in the 70s and 80s that is devoid of taurine their plasma concentrations of taurine decrease if you decide to become a vegan vegetarian your plasma concentrations of taurine as well as urinary concentrations will decrease because it is suggestive that that enzyme that we have also not like cats we haven't completely lost the ability but we don't do very well and similarly we can look at all these other enzymes and and pathways and what they tell us is that cats because they're getting these items these nutritional items preformed it doesn't matter whether they lose the ability to synthesize or not synthesize so here's that here's a good one right here is beta carotene beta we can make beta carotene and liver are we fightin a from beta carotene in the diet but cats can't do that at all they they simply become very deficient and ultimately die so that process in humans is inefficient so what can we say we're not obligate carnivores but we've moved down that metabolic pathway towards eating more and more animal foods so the question comes up then is how much plant food and how much animal food were actually consumed in these these ancient diets and so there really is no answer it's kind of like well you know is there a single Paleo diet no there was a variety of plant animal food subsistence ratios and that's what our group actually went in and analyzed we analyzed what's called the ethnographic data and ethnographic data is historical data that has been published by people that went out in the field looked at hunter-gatherers frontier doctors and they made notes about these folks so it's pretty loose data it's not randomized controlled trial it's not empirical it's more subjective but anyway it's the only day that we have so we went in and reanalyzed the 229 hunter-gatherer societies that were reported in the ethnographic atlas and here's what our data showed is that if we looked at the subsistence dependence on gathered plant foods there were as I mentioned 229 hunter-gatherer societies and these little blocks here called class intervals so 0 to 5 percent plant food all the way up to 86 to 100 % plant foods and the statistical analysis what we did is we looked at the mode which is the most frequently occurring value 26 to 35 percent plant food and the median the value at which the numbers 1/2 fall above and half fall below is the medium and that spout w
as found in the same class interval 26 to 35 percent so basically that's indicative of what the average hunter-gatherer was doing in terms of plant foods about quarter to a third of their calories came from from plant foods and if you notice up here there was not a single vegetarian or vegan Society of all 229 and only thirteen and a half percent of these hunter-gatherer societies had greater than 50% of their calories from plant foods so at least the ethnographic data is supportive of the notion that we were eating more animal foods and that's included both hunted and fished and gathered as well animal foods and so you can see here that the representative value the mode and the median falls in this 55 to 65 percent so a little more than half the calories to two-thirds seemed to typically come but once again as I mentioned this is really kind of soft data ethnographic data is not empirically based and so there's lots of room for error here and we we did actually compile the hunter/gatherer data in which we have quantitative studies and I can tell you the photographs that I've looked at from this time period look at how rip these guys are look at those six pack AB so that's pretty characteristic of our ancestors that weren't eating processed foods so this is a paper we published in 2002 and European journal clinical nutrition in it we actually compiled the 13 quantitative studies in which people had gone into the field they measured the amount of food the weight then they went back they got the caloric values for those wild plant foods and then they made a fairly good estimate and notice here that the numbers we see are about 70% animal 30% plant but when we eliminate the very far north societies the Eskimos and the Inuit that live above or the noonah mute that live above 60 degrees north latitude well they have no choice but to eat only animal food most of the year when we eliminate those we see a number then it approaches the ethnographic numbers of about a third to plant food to two-thirds animal food this is my colleague Mike Richards work he was at Oxford when he did this study and he examined another isotope that is found in the collagen of these fossils if the collagen is intact and he compared Neanderthal Delta 15 nitrogen in two speed or two examples of Neanderthal two specimens and he contrasted them to fossils that are found alongside the Neanderthal so we know they're from the same time frame a wolf and arctic fox and then here's some herbivores that they find and you can see that the signature of the Neanderthals indicates that they were eating a ton of protein from animal food well Neanderthals aren't us that's a different species and so they were living in Europe during very cold periods so let's take a look at the data let's go fast forward in time to England and this data comes from about ten or twelve thousand years ago you can see it was dated in a place called Gus cave in England twelve thousand three hundred years ago and once again the same Delta 15 nitrogen of these and these are modern-day humor they were exactly like us no difference exactly like us and you can see that they against again we're having a signature that was even greater than an arctic fox but nothing like a deer a horse or an ORAC or ox so the animals we domesticated to become cows alright so this is the known if we look at the plyo Pleistocene period that we talked about these are the foods that simply couldn't have been consumed because they didn't have the technology to make these highly processed foods that are essentially formed 70% of the calories in our diet so one thing that's kind of interesting and I give interviews and to the media and the press all the time is that the average person on the street is unaware that we eat the same four things every day day in and day out okay and so 70% of our calories comes from refined vegetable oils cereal grains refined sugars and dairy products if you eliminate those then what's left and I'll show you here in a minute so every single day of life of the average American they eat those those foods in processed forms in one way or another so this is another way of looking at this and so I've deliberately made this pie chart in which those four food groups dairy grains refined oils and refined sugars are in white because they're very nutrient they're poor a nutrient density and so what they do is they displace the more colorful foods and you can see here that meats and fish and nuts and fruits and veggies then are a very nutrient dense and what I'm suggesting people ought to do is with modern foods is to or with a modern diet eliminate these foods so that you allow all these nutrient-dense foods to fill in here's another way of looking at the the Western diet we can talk about as it evolved and the Neolithic was the first major change once we no longer were hunter-gatherers but were farmers this was the Neolithic period from 10,000 to about 5500 years ago this is when things really started to change we started to domesticate animals we started to domesticate cereal grains we settled down in villages and even though 10,000 years ago seems to be historically remote if you look on it from an evolutionary timescale notice that 10,000 years is really very very small in terms of human generations only 333 human generations have come and gone since agriculture began in the Middle East and for most of us it's even shorter still most people of Northern European ancestry agriculture didn't come into play until about five or six thousand years ago okay if we move even faster forward we can look at the industrial era which started about 200 years ago and this is when things really got geared up in terms of processing foods sucrose really wasn't available to the average citizen until about 200 years ago with the advent of the steam engine and being able to get sugarcane from the tropics back up to northern latitudes and do it inexpensively so this is when people could start eating refined sugar in high quantities feedlot produced beef were only made possible with the advent of steam locomotives in which you could get cows to market along with huge amounts of grain and put them into a feedlot so this is you can see less than five human generations since we started making beef that looks like it does now refined grains are very recent in our diet because the machinery to make refined grain steel roller mills didn't exist until the 1880s vegetable oils hydrogen or hydrogenated oils and most people in this crowd are old enough to remember a time or many people are when we didn't put high fructose corn syrup into our diet this is kind of a fun one and I I've got a little mini paper and it shows pretty much the advent of junk food so believe it or not there actually was a time when we didn't have Hershey's chocolate bars at the supermarket and here's there's a couple ones here that are kind of fun here's M&Ms 1941 I remember coaching a being an assistant coach on a women's swim team we would go on break you'd have to go to the bathroom go into a service station and they'd empty out the candy machine you know girls at that age they're swimmers they were just absolutely craving these refined sugars so look at that 1913 an Oreo cookie I can't believe they'd invented those they'll never they'll never go away though you know okay so when you look at this thing in an it's in entirety and you look at the neolithic and the industrial era of foods and what they do they displace all those other healthy foods but in a couple of papers that we've examined the nutrient content you can see what's going on here it disrupts these nutritional factors these major nutritional factors the glycemic load the fatty acid balance the macronutrient balance and I'll talk about how all of these things changed trace nutrients vitamins minerals phytochemicals acid base sodium potassium and fiber and to this list as Alex had mentioned you can probably talk about anti
nutrients because the typical Western diet contains high levels of anti nutrients and in the swansong of my career that's what I've been focusing on is how anti-nutrients disrupt the gut biome and predisposes for autoimmune disease but that's another lecture okay so let's take a look at cereal grains you know cereal grains of the staff of life and hunter-gatherers didn't eat cereal grains and so they comprise roughly a quarter of the calories in the typical Western or US diet unfortunately we eat our cereal grains as refined grains rather than whole grains am I saying whole grains better idea not necessarily there's trade-offs with both of them so what are grains the seeds of grasses and in their wild state they're typically very small difficult to harvest and they're really into jess tubulin less you grind them down and then cook them so that's what you have to do to make them edible and with hunter-gatherers they didn't like to do that there's a concept called optimal foraging theory in which they're trying to get the most bang for the buck so the amount of energy that they expend has to be equivalent to what they get back and if you've got to put all this processing energy into eating it then they become starvation foods so the appearance of these these are called saddle stones these crude grind stones in the middle-east roughly ten to fifteen thousand years ago heralds the beginning of humanity use of cereal grains is staple and once again we published a little rebuttal in the Proceedings of the National Academy and then we published a more extensive paper my colleagues Pedro and Milan who will be speaking to you later on we wrote a little bit larger article on this notion and rebutting the idea that people were eating grass seeds and grains way way back so up until about 1880 this is how cereals were milled you can see here's a woman still started two thousand twenty five hundred years ago we invented water wheels so that we could turn these great big heavy stones with the force of a machine and the inherent difference with the new technique is that these things grind the the entire seed together so the endosperm the germ the brand they all are in the flour and unless you go through another step to remove them then that's how bread and flour were made until for the average person until the 1880s in the 1880s steel roller mills came into play and they fundamentally break the wheat very differently they squeezed the wheat berry so they squeezed the germ out of it and then it's very easy to sieve off the germ and the fiber and have nothing left but the endosperm and when you do that what it does is it creates a flour that is very very fine and has a high glycemic index and so in this chart right here you can see you can start off with a whole wheat kernel and it has very low glycemic index and the more and more fiber and bran we take out the higher the glycemic load becomes so we produce this nice beautiful white uniform flour but physiologically we do all kinds of damage to our bodies and in 1880 and 1900 the glycemic index was still a hundred years in the future so we didn't understand what it was we were doing and as you can see here virtually all processed foods that are made with grains whether it's wheat or corn or rice or you name it they typically have high glycemic indices and high glycemic loads this is my colleague Jenny Brand Miller's work and she published this stuff and she continues to do so and so she arbitrarily drew a line in the sand and said that medium likes emic index foods are between 55 and 70 I don't agree with that so I've been down to Australia a few times and I think more importantly it's the glycemic load so it's the glycemic index times the amount of carbohydrate not in a standard portion but in an equivalent portion so I think you have to look at an equivalent portion to make the plain feels level so this is David Ludwig's work and semen lose and and this is some of the earlier stuff that really kind of told the public a few vitamins we call it enriching it and so after World War two these B vitamins b12 and three were enriched as well as iron I'll show you that on the next slide and then starting in in nineteen ninety eight we put folic acid into all refined grains but paradoxically folic acid didn't exist until 1948 nobody on the planet ever ate folic acid until 1948 when chemists at leaderly labs synthesized the compound folic acid and Foley are not the same compound so when we refined grains you can see then that we're knocking the hell out of folate and this is what's left and then we replace it with folic acid and the reason that that was done is that it was thought well folic acid the liver turns folic acid into folate and it was thought that this would reduce the number of neural tube defects actually mortality from neural tube defects and we published a paper showing that yeah it did but was it significant we put 300 million people at risk by supplementing our diet with folic acid to save roughly a hundred and fifty lives okay so that's why it was done and there was only one other country that followed lockstep with the United States and that was Canada so none of the European countries decided to do that because there was experimental work at the time suggesting that this isn't a very good thing to do and what we've seen in the decade or decade and a half since the folic acid supplementation program is an increase in multiple epithelial cell cancers and so there's some really good randomized controlled trials in which they give people men in particular folic acid because folic acid also is supposed to reduce cardiovascular disease and turns out is what happens is that prostate cancer morbidity and mortality rose dramatically and in animal models we now have a mechanism of how this might work so this to my way of thinking is going to turn into enormous public health blunder that hopefully will be reversed in the not-too near future so mineral depletion occurs also with when we refined our grains and you can see here that virtually all minerals are are reduced when you consume a whole grain from a refined grain but this is misleading because in vivo in the body it doesn't work this way so what happens is most of these divalent ions iron and zinc and manganese and all of these are bound to phytate in a dose-dependent manner meaning that we don't absorb them anyway so when we eat whole grains we get probably even less iron then what we would get with fortified iron so it's a mission there's a trade-off here and the other trade-off is that whole grains are a much more concentrated source of anti nutrients which Pedro Bastas will be talking to you about later in the morning so there's a variety of diseases then that are associated with the reduced fiber content and one of the common questions that come up when people adopt Paleo day that they say how am I ever going to get my fiber if I reduce all these whole grains well you can see then on a per caloric basis here whole grains are a pretty source pretty poor source of fiber and the types of fiber that tends to have therapeutic effects in our body soluble fiber versus non soluble fiber except for oats grains don't have a whole lot of this or as you can see here fruits and vegetables are wonderful sources of fiber and if you take these things out of your diet you get plenty of fiber so how do we know that dairy products couldn't have been consumed so end of story right somebody in the popular press calls me I said have you ever been close to a wild animal no have you ever tried to milk a wild animal okay so you have to domesticate animals before you can milk them so that didn't happen until about 10,000 years ago you can see this is the content of dairy products in the typical Western and US diet about ten percent of total energy and this is data in which they actually look at the fatty acid composition on pottery shards and they can see that indeed that fatty acid composition comes from milk
and dairy products and so first dairy in evidence comes from the Middle East about 9,000 years ago we see it in Great Britain about 6,000 years ago all right one of the ideas that got me interested early on and once again the idea came for it as Alex kind of mentioned from this paleo template and it led me to not just rheumatoid arthritis but it led me to many other health problems so I take this evolutionary template and I place it over that whole idea and so we were some of the first people to blow the horn on diet and acne in the flagship the American Medical Association is flagship journal the archives of dermatology and that was 10 or 15 years ago so what led me to that was the same thing that led me to the rheumatoid arthritis that has now led me to autoimmune disease was this evolutionary template and you can see here is that if we look at the glycemic index of milk products they're very very low okay they're very very low so in theory they ought to be pretty good for insulin and glucose metabolism yet if we look at the insulin response it's like eating cookies or white bread or sugar so paradoxically the glycemic response and the insulin response have been disassociated and we were the second group internationally to point this out to my graduate student Garrett Hoyt and indeed we saw this effect and it was shown earlier by Jenny Brando group and a few other folks so the question comes up then is that a detrimental effect so some people have suggested that a low glycemic load and a high insulin response might be therapeutic animal models of that show that's not the case so if you ever go to an Italian restaurant and you order up veal okay what is veal it's calves very small cows that have been intensely fed milk over the first couple of months of their life and then they're slaughtered and so this is well known in the animal science community that doing that feeding high milk diets way beyond what they could ever get from suckling from their mother essentially forced feeding a milk causes insulin resistance hyperglycemia and these other problems so there's only been one study in the clinical literature with humans this is Kristin Hoppy's group and she reported in a jcn in 2005 that if you gave these young boys their protein as either milk or meat during the arm of the study in which they were fed milk they all became insulin resistant so we need to replicate this study in adults and have colleagues that are on the process hopefully of doing this shortly okay so we ate wild animal foods which are it's really not practical to do that anymore but what are what are the changes that occur in the nutrient content of animal foods as we go down the line here from wild to grass produce to grain produced so our ancestors ate everything they the entire carcass whereas what we eat is simply the muscle meat when we talk about me that's what we eat and most typically it's grain produced or processed and so here you can see if we look at the fat content by energy not by weight of America's favorite meats you can see there the not meat at all their fat disguised as meat so very high fat concentration in these and it doesn't look anything like wild animals and we've done those experiments we've actually done that and in wild animals the body fat content waxes in ways seasonally yet once we domesticated animals we could provision them with food and we weren't stupid we slaughtered them and that when they are at peak fat content because we could do that we're at the mercy with wild animals whatever fat they have is the fat they have and so this represents the change in body fat in caribou over the course of a 12-month period and this is fairly reminiscent of not just North American but also European and African mammals that humans would have preyed on so you can see that the body fat over the course of seven months is quite low it's about three or four percent anybody that knows about body fat realizes that in humans this is a very very low value and in North America only during the fall and that's what we have hunting seasons in the fall does the body fat increase so we did these experiments a decade ago and we analyzed the total fat the fatty acid content in wild animals grass produced animals and grain produced animals and you can see here that the amount of fat in this feedlot cattle is an order of magnitude higher and you don't have to be a scientist to do the analysis look at the differences in the carcass there's no subcutaneous fat here whereas these guys have three or four and five inches and the triglyceride infiltrates the the muscles here and you don't have that with wild animals so it wasn't until about 150 years ago that we started to do this started to feed aunt cows grains and it fundamentally altered a couple of factors it changed the fatty acid balance it reduced the omega-3 content it reduced the macronutrient balance and now we're producing a meat that contains a lot less protein and because there are less vitamins and minerals in fat than there are in protein we reduced the nutrient content as well with that process this just contrasts the the omega-3 and omega-6 fatty acids between grass and grain produced animals and the big problem here is the high levels of linoleic acids so you can see we have maybe 50 or 60% more linoleic acid and that that does represent a problem I will try to finish up here on time at 9 o'clock we'll take a short little break and then I'll come back and do my second one so potentially we can at least add to the amount of omega-3s in our diet by eating grass fed the amount of mega threes that we need or roughly 10 times higher than what you would get from a quarter gram serving here so these are part of the solution and not part of the problem but they don't cure the problem and I'll talk to you how we'll do that later okay added salt is rarely consumed we eat about 10 grams of salt primarily you can see from processed food a little bit from cooking and very little in naturally occurring foods this is a mountain of salt found in catalona Spain and when I went over and spoke to my friends Milan and Pedro and showed this slide about half the audience put their hand up said I know where that place is they've actually seen that mountain so salt was rarely used by hunter-gatherers perhaps those living close to the ocean may have dipped their food in salt water but inland hunter-gatherers there's really no precedents for it and here's the laundry list of diseases that are associated with the high salt content here's one as practitioners you may not know this comes from an obscure paper in the journal of the American Medical Association 1944 and if you have patients that aren't sleeping well get the salt out of their diet another one this comes from our group is exercise induced asthma we blew the whistle on that a number of years ago and let's talk about refined sugars depending on whose numbers you're looking at anywhere from 15 to 20 percent of total calories this is USDA disposal data this is where it comes from it's changed a little bit over the course of the year hunter-gatherers are hard-wired for sweets and fatty foods the brains seek it out because it has survival value but they couldn't eat it in unlimited quantities so honey would have always been consume but it was only available seasonally this is good per capita disposal data out of Europe showing that prior to the Agricultural Revolution hardly anybody in Europe ate sugar so Denis were out of business this is data from England and you can see then that except for the two world wars sugar consumption rose steadily into about 1970 this is data from the United States over the last hundred years or so and we've actually made a little bit of inroads into refined sugar consumption it peaked in 2000 and over the last decade it started to decline a little bit there was a fundamental change made in the types of sugars that we were consuming prior to the advent of high fructose corn syrup being m
ade with this technology that you see up here most of the sugar came from sucrose so is there any difference between sucrose and fructose in terms of how it influences our body a little bit ok so one is a compound and and and one or two elements so we have an enzyme in our gut to break sucrose into glucose and fructose so it may be a little bit less problematic but probably not much so you can see then that hi this is our data high fructose corn syrup is increased dramatically over the course of the last 30 or 40 years and this parallels nicely the obesity epidemic in the United States and so many people think that fructose is underlies part of the problem I don't think it's the only problem but I think it certainly it's part of it so you can see then that it all peaked in about 2000 as I mentioned fructose and sucrose have similar effects in the body but not identical so here's some of the diseases that are associated obviously dental caries any society that consumes high amounts of sugar typically ends up with dental caries there are individuals that seem to be resistant but as a population most don't do so well the metabolic syndrome now is very well characterized and also epithelial cell cancers through mechanisms that we outlined in 2004 that are now fairly well recognized is that breast colon and prostate cancer all tend to be promoted via the hormonal cascade that insulin resistance produces okay vegetable oils they comprise about 18% of total calories and we use these in all kinds of processed foods and you can see how they're broken down prior to the Industrial Revolution the only way to make these things was by rendering and pressing and so the first oils that were made were traditional olive oils and flax oils and what have you most the oils were used for lubrication and not as food oils and so starting in in the last century or so you can see this machine up here this is a steel expeller and it creates an enormous amount of pressure and it can extract oils out of seeds that you like corn corn doesn't seem like it's an oily food but it can extract oil out of them and then by using purification procedures and in solvents and so forth you can get all of these non-traditional oils and put them into your diet the hydrogenation process was invented in 1897 so that we could harden them turn them into margarine and another shortening and other fats and this is a first time we end up with a specific type of fat trans Ladak acid in our diet and trans elated gas it seems to cause multiple adverse effects this is the per capita consumption of refined vegetable oils the United States and you can see starting in about 1900 we did practically very little at all and we almost increased that by 500% since the year 2000 tell you one little anecdotal story here and then we'll call it quits take a little break and come back and do the next lecture but my grandfather moved out to California Southern in the 1920s and he started a restaurant and in Hollywood and so his restaurant served probably about two or three hundred people maybe and after he died he died in the 40s my mother inherited all his stuff and one of the things she got was a cookbook that he had purchased back in 1913 that's what it was dated and it was a cookbook and a recipe on how to cook for 300 people and so I ultimately got that after my mother passed away and I went through that recipe book and the only oil in the entire recipe book was olive oil and there was very few recipes that used it they used lard and other fats but they certainly didn't use any anything near to what we use now so in that timeframe just in the three generations that I've lived this has gone from practically nothing in our diet to 20% of our calories so what are the problems with consuming high amounts of processed foods and refined vegetable oils it alters the fatty acid balance in our diet and most of these vegetable oils are very high in an 18 carbon fatty acid called linoleic acid and it used to be thought that linoleic acid was a good thing and there's still it's somewhat controversial in the scientific literature but not to my way of thinking and so this actually it was thought to lower blood cholesterol and reduce the risk for heart disease but reanalysis of some of the classic studies by joe hibblen and and other folks in our group showed exactly the opposite and so linoleic acid tends to be pro-inflammatory so this is a bad thing so if you've got and guess what inflammation drives all chronic disease you can't have heart disease you can't have cancer and you can't have autoimmunity without up regulation of the pro-inflammatory response so this is involved in that problem and that's why you can see it is associated with all those diseases so in all of their brilliance the USDA came up with a new thing they went from the food pyramid to my plate but for me it was even easier to zap this one all I had to do is put an X over here and an X here and now we're kind of back to paleo so there's some fundamental differences we have with that but this is what I think people ought to try to do is you should emulate not exactly or precisely the diets of hunter-gatherers we can't do that and I'll show you in the next lecture how it's impossible but what we should try to do is to emulate the food groups that they consumed and eliminate the food groups that they didn't consume so this is what I think we ought to do thank you then the next lecture is a little bit shorter so want we take a five to seven minute break try to be back here between five after and ten after and we'll get going on the next lecture and hopefully have a little bit of time for Q&A at the end of all these lectures .

Video Description:

There is growing awareness that the profound changes in the environment (eg, in diet and other lifestyle conditions) that began with the introduction of agriculture and animal husbandry ≈10000 y ago occurred too recently on an evolutionary time scale for the human genome to adjust. In conjunction with this discordance between our ancient, genetically determined biology and the nutritional, cultural, and activity patterns of contemporary Western populations, many of the so-called diseases of civilization have emerged. In particular, food staples and food-processing procedures introduced during the Neolithic and Industrial Periods have fundamentally altered 7 crucial nutritional characteristics of ancestral hominin diets: 1) glycemic load, 2) fatty acid composition, 3) macronutrient composition, 4) micronutrient density, 5) acid-base balance, 6) sodium-potassium ratio, and 7) fiber content. The evolutionary collision of our ancient genome with the nutritional qualities of recently introduced foods may underlie many of the chronic diseases of Western civilization.

November 19, 2020 Tags : caveman diet , celiac disease , diet (industry) , Dieting (Symptom) , Evolutionary Biology (Field Of Study) , health , Hunter-gatherer , Ketogenic Diet (Medical Treatment) , low carb , Nutrition (Medical Specialty) , Paleo , Paleo Diet , primal diet , Video , Weight

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