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Human Ancestors Were Nearly All Vegetarians

The views expressed are those of the author and are not necessarily those of Scientific American.

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Paleolithic diets have become all the rage, but are they getting our ancestral diet all wrong?

Right now, one half of all Americans are on a diet. The other half just gave up on their diets and are on a binge. Collectively, we are overweight, sick and struggling. Our modern choices about what and how much to eat have gone terribly wrong. The time has come to return to a more sensible way of eating and living, but which way? One group of self-help books suggests we give up carbohydrates, another that we give up fats, another still that we lay off the protein. Or maybe we  should just eat the way our ancestors did. A new class of very popular self-help books recommends a return to the diets of our ancestors. Paleolithic diets, caveman diets, primal diets and the like, urge us to remember the good ole days. Taken too literally, such diets are ridiculous. After all, like all wild species, sometimes our ancestors starved to death and the starving to death diet, well, it ends badly. The past was no panacea; each generation we made due with the bodies and foods available, imperfect bodies and imperfect foods. But let’s pretend, for the sake of argument, that it would be a good idea to eat like our ancestors ate. Just what did they eat?

Here is where the trouble starts. Collectively, anthropologists have spent many a career attempting to hone in on the diets of our most recent ancestors. Typically, they focus on our stone age (AKA Paleolithic) human ancestors or our earlier pre-human, hominid ancestors. Even if we just consider our stone age ancestors—those folks whose stories span the time between the first stone tool and the first agriculture—the sides of the debate are polarized. If you listen to one camp, our ancestors got most of their nutrition from gathered fruits and nuts; successful kills of big mammals may have been more of a treat than an everyday reality. A paper out just this month suggests that even Neanderthals–our north country cousins and mates– may have eaten much more plant material than previously suspected.  Meanwhile, more macho camps of academics paint a picture of our ancestors as big, bad, hunters, who supplemented meaty diets with the occasional berry “chaser.” Others suggest we spent much of our recent past scavenging what the lions left behind, running in to snag a half-rotten wildebeest leg when the fates allowed.  In other words, athough “Paleolithic” diets in diet books tend to be very meaty, reasonable minds disagree as to whether ancient, Paleolithic diets actually were. Fortunately, new research suggests answers (yes, plural) to the question of what our ancestors ate.

The resolutions come, in part, from considering the question of our diets in a broader evolutionary context. When we talk about “paleo” diets, we arbitrarily tend to start with one set of ancestors, our most recent ones. I want to eat like Homo erectus or a Neanderthal or a stone age human, my neighbors testify. But why do we choose these particular ancestors as starting points? They do seem tough and admirable in a really strong five o’ clock shadow sort of way. But if we want to return to the diet our guts and bodies “evolved to deal with” (a concept that wrongly assumes our bodies are fine tuned by engineers rather than cobbled together by natural selection), perhaps we should also be looking our earlier ancestors. In addition to understanding early humans and other hominids, we need to understand the diet of our ancestors during the times when the main features of our guts, and their magical abilities to turn food into life, evolved. The closest (albeit imperfect) proxies for our ancestral guts are to be found coiled inside the living bodies of monkeys and apes.

I should start by explaining what the “gut” is and does; I use the term too loosely. What I really mean is the alimentary canal and all of its gurgling bells and whistles. This canal is the most important and least lovely waterway on Earth. It takes you from the mouth through the body all the way down to the anus. But while most canals take the shortest course between two points, the one inside you takes the longest. The longer the canal, the more area over which digestion can occur. Food enters the canal through the mouth, where it is chewed and slimed with saliva. It then hits the stomach, where proteins are digested (and, I think, bacteria are filtered). Next, it is on down to the small intestine where simple sugars are absorbed. If you have just eaten a twinkie, the process essentially ends there. Everything worth consuming has been absorbed. But if you have eaten broccoli, an artichoke or a fig, things are just beginning. It is in the large intestine, where harder to break down carbohydrates (such as cellulose, the most common plant compound on Earth) are torn asunder. This system evolved so as to provide us with as many calories as possible (long to our benefit) and, also, as many of the necessary but hard to produce nutrients. The alimentary canal is, evolutionarily speaking, a masterwork. It makes energy from the food we are lucky enough to find 1.

Although all guts are sublime, just how they do what they do varies among species, much as do the leaves on trees or beaks on birds. When considering evolution’s great innovations, Darwin dallied among the beaks, but he might just as well have focused on the gut or even simply colons2. A beak can pick something up, maybe crush it. Big deal. A colon can jump start the process of turning a bit of rotten fruit or leaf into usable energy and ultimately life. Science can replicate a beak; it is still working on making a good replica of a colon, much less replicating the great variety of colons and guts more generally found in nature. Carnivores such as lions have smooth stomachs big enough to hold a good sized hunk of a small antelope. In them, the muscles of prey are returned to the bits of protein out of which they are made. The stomachs of some herbivores on the other hand are dense with hair-like villi and, moving among them, the bacteria that aid in the breakdown of plant cell walls and their cellulose. The stomach of a cow is a kind of giant fermenter in which bacteria produce huge quantities of specific fatty acids the cow can easily use or store (You eat some of those fatty acids when you eat a cow). In other species, the stomach scarcely exists and fermentation takes place in a greatly enlarged large intestine.

Yet, for all of the vulgar and magnificent elaborations on the theme of tubes to be found inside animals, the guts of humans are boring (although see footnote 5). Our guts are remarkably similar to those of chimpanzees and orangutans–gorillas are a bit special–which are, in turn, not so very different from those of most monkeys. If you were to sketch and then consider the guts of different monkeys, apes and humans you would stop before you were finished, unable to remember which ones you had drawn and which ones you had not. There is variation. In the leaf-eating black and white colobus monkeys (among which my wife and I once lived in Boabeng-Fiema, Ghana) the stomach is modified into a giant fermentation flask, as if the colobus were kin to a cow. In leaf-eating howler monkeys the large intestine has become enlarged to take on a similarly disproportionate role, albeit later on in digestion. But in most species things are not so complex. An unelaborated stomach breaks down protein, a simple small intestine absorbs sugars and a large (but not huge) large intestine ferments whatever plant material is left over. Our guts do not seem to be specialized hominid guts; they are, instead, relatively generalized monkey/ape guts. Our guts are distinguished primarily (aside from our slightly enlarged appendix) by what they are missing rather than what they uniquely possess. Our large intestines are shorter than those of living apes relative to the overall size of our gut (more like 25% of the whole, compared to 46% of the whole in chimps). This shortness appears to make us less able to obtain nutrients from the cellulose in plant material than are other primates though the data are far from clear-cut. The variation in the size and details of our large intestines relative to those of apes or gorillas have not been very well considered. In a 1925 study the size of colons was found to vary from one country to the next with the average Russian apparently having a colon five feet longer than the average Turk. Presumably the differences among regions in colon length are genetically based. It also seems likely that the true human colonic diversity has not yet been characterized (the above study considered only Europe). Because of the differences in our colons (and ultimately the number of bacteria in them) we must also vary in how effectively we turn cellulose and other hard to break down plant material into fatty acids. One measure of the inefficiency of our colons is our farting, which we all know varies person to person. Each stinking fart is filled with a measure of our variety.3 Aside then from the modest size of our colon, our guts are strikingly, elegantly, obviously, ordinary.


Image 1a (left). Chimpanzee eating an ordinary food, a fig.  Photo courtesy of Alain Houle.

Image 1a (left). Chimpanzee eating an ordinary food, a fig.

So what do other living primates eat, the ones with guts mostly like ours, eat? The diets of nearly all monkeys and apes (except the leaf-eaters) are composed of fruits, nuts, leaves, insects, and sometimes the odd snack of a bird or a lizard (see more about chimpanzees). Most primates have the capacity for eating sugary fruit, the capacity for eating leaves and the capacity for eating meat. But meat is a rare treat, if eaten at all. Sure, chimpanzees sometimes kill and devour a baby monkey, but the proportion of the diet of the average chimpanzee composed of meat is small. And chimps eat more mammal meat than any of the other apes or any of the monkeys. The majority of the food consumed by primates today–and every indication is for the last thirty million years–is vegetable, not animal. Plants are what our apey and even earlier ancestors ate; they were our paleo diet for most of the last thirty million years during which our bodies, and our guts in particular, were evolving. In other words, there is very little evidence that our guts are terribly special and the job of a generalist primate gut is primarily to eat pieces of plants. We have special immune systems, special brains, even special hands, but our guts are ordinary and for tens of millions of years those ordinary guts have tended to be filled with fruit, leaves, and the occasional delicacy of a raw hummingbird4.

 1b (right). Chimpanzee eating a rare delicacy, a colobus monkey. Photo courtesy of Alain Houle.

1b (right). Chimpanzee eating a rare delicacy, a colobus monkey. Photo by Joanna Lambert.

“But wait dude,” you might say, you have not gone far enough back in time. After all, most of the details of our guts, the size and shape of its different parts, are even older. Even prosimians, lemurs and their other adorable kin have guts similar to our guts. Maybe they were carnivores and we can still be “paleo” and eat a ton of meat? Maybe in thinking about our guts, we should look to the prosimians. Sure enough, most prosimians are (and likely were) carnivores. They eat and ate meat, BUT most of that meat comes from insects. And so if you are serious about eating a really old school paleo diet, if you mean to eat what our bodies evolved to eat in the “old” days, you really need to be eating more insects. Then again, our guts aren’t so different from those of rats. Maybe the rats…  4.

Which paleo diet should we eat? The one from twelve thousand years ago? A hundred thousand years ago? Forty million years ago? If you want to return to your ancestral diet, the one our ancestors ate when most of the features of our guts were evolving, you might reasonably eat what our ancestors spent the most time eating during the largest periods of the evolution of our guts, fruits, nuts, and vegetables—especially fungus-covered tropical leaves.

Image 2. A Black and White Colobus Monkey eating leaves. Photo by Alain Houle.

Image 2. A Black and White Colobus Monkey eating leaves. Photo courtesy of Jessica Rothman.

Of course, there might be differences between our digestive system and those of other species that have gone relatively undetected. Maybe someone will discover rapid evolution in the genes associated with our digestion over the last million years, the sort of evolution that might signal that we had evolved specialized (but so far hidden) features to deal with diets heavier in meat, an adaptationist just so story that makes a big steak seem not like an indulgence but instead our evolutionary birthright. If you want a justification for eating a meaty “paleodiet,” in other words, the search should be for evidence that some aspect of our bodies evolved in such a way as to be better able to deal with extra meat or other elements of our stone age diets that differed from the primate norm.  It could be there, as of yet undetected.

If you want my bet, the majority of the recent (last few million years) changes in our guts and digestion will prove to have had more to do with processing food and, later, agriculture rather than with meat-eating per se. As hominids and/or humans switched to eating more meat, their bodies might have evolved so to be able to better digest meat. I could be convinced. But, we know our human digestive systems DID evolve to deal with agriculture and the processing (fermenting and cooking) of food. With agriculture, some human populations evolved extra copies of amylase genes, arguably so as to better be able to deal with starchy foods. The case of agriculture is the most clear. With agriculture, several human populations independently evolved gene variants that coded for the persistence of lactase (which breaks down lactose) so as to be able to deal with milk, not just as babies but also as adults. Drinking milk of another species as an adult is weird, but some human populations have evolved the ability. With agriculture, the species in our guts seem to have evolved too. Some populations of humans in Japan have a kind of bacteria in their guts which appears to have stolen genes for breaking down seaweed, a foodstuff that became popular along with the post-agricultural Japanese diet. With agriculture, human bodies changed so as as to cope with new foods. Our bodies bear the marks of many histories. As a result, if you want to eat what your body “evolved to eat” you need to eat something different depending on who your recent ancestors were. We already do this to some extent. If your ancestors were dairy farmers, you can drink milk as an adult without trouble, you’ve “got lactase.” But if they were not, you tend to get diarrhea when you drink milk and so you probably avoid the stuff (lest your friends avoid you). But the truth is, for most of the last twenty million years of the evolution of our bodies, through most of the big changes, we were eating fruit, nuts, leaves and the occasional bit of insect, frog, bird or mouse. While some of us might do well with milk, some might do better than others with starch and some might do better or worse with alcohol, we all have the basic machinery to get fruity or nutty without trouble. And anyway, just because some of us do better with milk or starch or meat than others doesn’t mean such foods are good for us, it just means that those individuals who couldn’t deal with these foods were more likely to die or less likely to mate.

What might be different, either between you and me or between you and me and our ancestors is the sort of gut bacteria we have to help us digest our food (which might also relate to the size and particulars of our colons). The new era in study of gut bacteria (and their role in digestion)—the era of the microbiome—may reveal that our stone age ancestors, by eating a little more meat, cultivated bacteria that help break down meat, which they then passed on to us (during birth which is messy and has long been), their maybe meat-eating descendents. Recent research by Joanna Lambert at the University of Texas, San Antonio and Vivek Fellner at North Carolina State University (my home institution) have revealed that the gut microbes of chimpanzees and gorillas do seem to work a little differently than those of monkeys (or at least the monkeys they studied). Bacteria from the guts of gorillas and chimps seem to produce more methane as waste than do those from monkey guts. Maybe this is just the tip of the fecal berg and the guts of different primates are fine-tuned to their diet in very sophisticated ways, including the fine-tuning of our own guts for eating more meat! Possibly, the next years will be exciting, both in terms of understanding the unique attributes of our microbes and the unique elements of our immune systems and the ways in which they regulate the composition of those microbes. These changes in bacteria might be mediated by changes in our immune systems themselves and how they relate to the microbes processing our planty food. Interestingly, if our gut bacteria responded rapidly to shifts in diets toward more meat during the stone age, they might be expected to have shifted again when we began to farm, at least for those of us with ancestors who began to farm early. When our gut bacteria met up with our agricultural diets, beginning twelve thousand years ago or so, they would have begun to compete with new microbial species that kicked ass at living off wheat, barley, corn, rice or any of the other grasses that have come to dominate the world, sometimes at our expense. This may even mean that which diet is best for you depends not only on who your ancestors were, but also who the ancestors of your bacteria were.

Image 3. A blue monkey eating a fig. Photo courtesy of Alain Houle.

Image 3. A blue monkey eating a fig. Photo by Joanna Lambert.

So, what should we eat? The past does not reveal a simple answer, ever.  Our bodies did not evolve to be in harmony with a past diet. The evolved to take advantage of what was available. If the best diet we can, with billions of dollars invested in nutritional studies, stumble upon is the one that our ancestors of one or another stage happened to die less when consuming, we are in trouble. Should we take our evolutionary past into account when figuring out the optimal diet. Yes, definitely. But there are two big caveats. First, our evolutionary history is not singular. Our bodies are filled with layers of evolutionary histories; both recent and ancient adaptations, histories that influence how and who we are in every way, including what happens to the food we eat. The recent adaptations of our bodies differ from one person to the next, whether because of unique versions of genes or unique microbes, but our bodies are all fully-equipped to deal with meat (which is relatively easy) and natural sugars (also easy, if not always beneficial), and harder to digest plant material, what often gets called fiber.5 Our ancient evolutionary history influences how we deal with these foods, as does our stone age past, as do the changes that occurred to some but not all peoples as agriculture arose. With time, we will understand more about how these histories influence how our bodies deal with the food we eat. But the bigger caveat is that what our histories and ancestral diets offer is not an answer as to what we should eat. It is, more simply, context. Our ancestors were not at one with nature. Nature tried to kill them and starve them out; they survived anyway, sometimes with more meat, sometimes with  less, thanks in part to the ancient flexibility of our guts.

As for me, I’ll choose to eat the fruits and nuts like my early ancestors, not because they are the perfect paleodiet but instead because I like these foods and modern studies suggest that consuming them offers benefits. I’ll supplement them with some of the great beans of agriculture, too much coffee, maybe a glass of wine and some chocolate. These supplements are not paleo by any definition, but I like them.  What should you eat? The truth is that many different diets consumed by our ancestors–al insect diet, mastodon diets or whatever you please–would be, although some perfect panacea, better than the average modern diet, one so bad that any point in the past can come to seem like the good ole days, unless you go too far back to a point when our ancestors lived more like rats and probably ate everything, including their own feces. Sometimes what happens in paleo should really stay in paleo6.

1-Well, into you and into excrement.
2- It would have suited him. After all, he took great pains to document his own bowel movements.
3- The most widely cited comparison of the guts of chimps, humans, gorillas and orangutans has sample sizes of one individual for both chimps and orangutans, so just how much larger the large intestines of chimps or orangutans are relative to ours is not yet known. Our relatively short large intestines might be an adaptation to our special diet, but might also be the consequence of a tradeoff between investing in big brains and big intestines. Or some mix thereof. Along these lines, it has been suggested that our shift to eating more meat historically might have allowed investment in bigger brains which might, in turn, have required us to eat more meat so as to feed the bigger brain and simultaneously made our large intestines and their fermentation less necessary. This idea is interesting and many-layered and comes with a number of untested but testable predictions. It would be fun to explore the genes associated with the changes in the size of our large intestine and when and whether they underwent strong selection.
4-For a review of the ecology and evolution of primate guts, see the excellent work by my friend and colleague, Joanna Lambert. For example… Lambert JE. Primate nutritional ecology: feeding biology and diet at ecological and evolutionary scales. In Campbell C, Fuentes A, MacKinnon KC, Panger M, and Bearder S (eds): Primates in Perspective, 2nd Edition, Oxford University Press or Lambert, JE (1998) Primate digestion: interactions among anatomy, physiology, and feeding ecology. Evolutionary Anthropology. 7(1): 8-20.
5-Sometimes it takes a friend to say things just right. In defense of human guts, my friend Gregor Yanega at Pacific University offered, “Our guts are special because they are less specialized. They can accomodate so many changes in the foods that surround us, can accomodate unusual abundance and a certain amount of scarcity: we can even eat some of the world’s more difficult foodstuffs: grains, leaves, and plants. Berries, nuts, meats, sugars, those are easy. Eating them together is pretty rare.”
6-I know, what I have shown is not that our ancestors were vegetarians but instead that they tended to mostly eat vegetable matter. Here though I am using the definition of vegetarian that most humans use where someone is a vegetarian if they decline meat in public but occasionally, when no one is looking, sneak a beef jerky. The modern vegetarian’s illicit beef jerky is the ancestral vegetarian’s crunchy frog.

For another take on the troubles with looking to history for idealized answers to our modern problems see Marlene Zuk’s great article in the New York Times:

Rob Dunn About the Author: Rob Dunn is a science writer and biologist in the Department of Biology at North Carolina State University. His first book, Every Living Thing, told the stories of the sometimes obsessive, occasionally mad, and always determined, biologists who have sought to discover the limits of the living world. His new book, The Wild Life of Our Bodies, explores how changes in our interactions with other species, be they the bacteria on our skin, forehead mites or tigers, have affected our health and well being. Rob lives in Raleigh, North Carolina with his wife, two children, and lots of microbes. Follow on Twitter @RobRDunn.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. lawman108 11:22 am 07/23/2012

    I believe there is no resaonable basis for arguing what we should eat now from what we or some other species ate eons ago. Most of the problems that result from diet come after what would have been the life expectancy of our forbearers. While the age is going down as the problem is going up, changes in life style and culture as a whole, it seems to me, hugely tump any argument for ancient diets.

    However, there are some things that don’t get said in the discussions over diet. One is that skinny people may not be the best people to ask what is the best diet for someone who is pre-disposed to getting fat. As someone in the latter category, I hear with some discust people say that if we would just push back from the table and go get some exercise, we would be skinny like them. When I can, I often ask that person whether, “if some credible source told you that you would live ten years longer by gaining 100 pounds, could you do it?” They don’t even have to answer; you can tell by the look on their face.

    The difference is probably not psychological. I think they just digest food differently, and don’t feel the need for as much food. They don’t get as hungry.

    In my case, I finally stopped listening to the idea that fat is bad and carbs are good. That kind of diet left me hungry; not psychologically unsatisfied–HUNGRY. Now I don’t eat high glycemic carbs and I eat all the meat I want. Teh result is that I have lost a lot of weight, I am not hungry, AND I actually eat fewer calaries (although I don’t count them). The stuff about insiline and carbs causing weight gain seems to be true in my case.

    I am aware that red meat is found not good for me in cohart studies, but the percent difference on an absolute measure as opposed to comparitive percents is not that high, and there are other things I can do to counteract the risk, such as adding nuts to my diet and taking natural anti-inflamatories.

    There is a tendency by some to want meat to be bad for our diets, because they don’t like the idea of eating other living creatures. I get that, but it is not scientific.

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  2. 2. bubba29 12:41 pm 07/23/2012

    as i understand it, hard to break down vegetation digestion occurs in the large intestine of the human gut. most of what you say is our “ancestral diet” is this hard to break down vegetation. i could be wrong but isn’t our large intestine about 20% by volume of our gut compared to 50% in other primates?

    also, you fail to mention a very important and unique difference in human digestion compared to other primates, cooking. this cannot be ignored because it helps with the digestion of all types of foods.
    to compare the digestive systems of primates that don’t cook to primates that do is not valid in my opinion.

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  3. 3. edevries 2:27 pm 07/23/2012

    This article has little to no relevance to anything that’s typically called a “paleo” or “primal” diet, because you’ve based it entirely on the assumption that these diets are about copying an ancestral diet wholesale. There’s little evidence that you’ve actually done any research on the claims of prominent proponents of those diets (e.g. Robb Wolf and Mark Sisson) but if you had, the first thing you’d learn is that it is not (repeat: NOT) re-enactment of any particular ancestral diet! Rather, it is about taking cues from these diets while looking to modern scientific results for verification/refutation of these ideas. Little of what you wrote would be a surprise to authors like Wolf or Sisson, nor would either give blanket disapprovals of consuming coffee, red wine, chocolate, butter, or any number of other neolithic foods.

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  4. 4. Fausto Levantesi 3:30 pm 07/23/2012

    1) This article is totally biased against meat consumption. For exemple, there is no scientific evidence that our digestive system is not made to handle large quantities of meat perfectly: the author’s semplistic considerations about the comparative anatomy of digestive tubes are naives and totally irrelevant.
    2) A review about paleolithic diets cannot omit a discussion about the utilization of cooked vs raw food. The author seems to forget that the mutations of the genes for amylases were introduced only when man began to cook grains, that is 10000 years ago. Cooked grains is a totally different food from raw grains, both from a nutritional and a metabolical point of view. It’s logical that a mutation was required, because our genetic heritage concerned only raw food. Some of us would even say this adaptation is still inadequate and that we would still need further mutations if we wanted to thrive on cooked grains. But the point is: when 2 million years ago the genus Homo began consuming more meat, it didn’t need any adaptation at all, because enzymes for raw meat had always been present.

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  5. 5. jgrosay 3:36 pm 07/23/2012

    Huh! I have the hunch that some word mixing took place when writing this interesting article. Reliable sources point the cellulose is only partially digestible by humans, although it’s digestible for ruminants, but not directly by the animal, but from a population of bacteria it holds inside, that break cellulose into digestible starch, termites can do this with lignin, the hard component in wood, also with the help of bacteria, but even the assertion that cellulose is partly digestible for us sounds too optimistic, being part of the fiber that prevents out guts to produce little balloons in its sides because of contracting in empty and producing too high pressures inside the gut is enough for cellulose, may be some starch that it’s not exactly cellulose is digestible, but I keep on having doubts about this part of the article.

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  6. 6. slothlovechunk 4:13 pm 07/23/2012

    This entire article is irrelevant.

    Humans largely survived and thrived on animal products throughout the paleolithic. They helped make us human, they are one of the reasons why we aren’t more like chimps and gorillas, hanging around the equator engaging in copraphagia.

    This is some incredibly lazy scholarship, if you can call it that. I’ve never seen a more hand-wavy comparison of gut composition. Those who have done actual quantitative studies on human gut composition have concluded that we are specially adapted to consume animal food (not exclusively). The author could have saved himself a lot of time by looking for this research instead of making up his own arguably irresponsible hand-waving. Maybe the author is trying to be more like our chimp and gorilla cousins by not only believing but also consuming his own feces?

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  7. 7. edevries 4:13 pm 07/23/2012

    As a second point, it’s quite mendacious to put “vegetarian” in the title when you know quite well that they were not, your note #6 notwithstanding. These animals were most assuredly not “sneaking” animal products into their diet like a hypocritical human vegetarian. Nutritionally there can be quite a difference between a diet with a small amount of animal products and one with none– as the widespread B12 deficiency in human vegans shows. These animals products you say they were “sneaking” very well could have been a nutritionally essential component of their diets.

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  8. 8. LordDraqo 4:52 pm 07/23/2012

    So we look at the gastro-intestinal tract, and completely ignore the dentition, which appears to be that of omnivores. The presence of incisors, cuspids and bicuspids indicate that tearing/cutting was a primary mode for eating, rather than crushing/grinding. However this is just my opinion, and I could be wrong.

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  9. 9. slothlovechunk 4:53 pm 07/23/2012

    As my own second, shorter, point, and all I really need to show this article as completely irrelevant.

    What “paleo” diet practitioners are interested in is not what we are able to digest. They are interested in what we can thrive on!

    Arguing whether we can digest nuts and seeds is not only a strawman (paleo practitioners will agree with you), it’s irrelevant. It’s whether or not subsisting on nuts and seeds is IDEAL, not whether or not it’s possible. For most practitioners it isn’t even what’s the most IDEAL thing TO eat, it’s what NOT TO eat a lot of.

    In most cases when you exclude agricultural products, animal products are the only recourse for facilitating one to thrive.

    This article tries to make the case that we can digest and survive on little animal products. No one in the paleo community will argue with that. The history of civilization proves this proposition. But what can we thrive on? That’s the argument. Everything here is irrelevant.

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  10. 10. Cyp450 6:49 pm 07/23/2012

    The article is more of a review of science of food and digestion than your average “eat well” column. From what I get out of the article, the current state science does little to tell us what is “perfect” meal for our health and well-being. The science may suggests that human may do well from eating vegi-diet or may be not…

    Just as the author suggested, each person is predisposed to different diets due to ancestral inheritance (including those common and uncommon traits). And then you have the issue of environmental variations each person is brought up at birth also affecting diet preferences. To say that there exist one “perfect” meal plan for all humans may be ideological. Of course you can always say with 95% confidence (or higher) that a certain food is good or bad for health but the qualifier that say I don’t belong to the group of outliers are in many cases missing.

    So for all it’s worth, my understanding of the article is that eat more plant stuff but do so with consideration of your body (which is what I do already).

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  11. 11. garyloewenthal 7:02 pm 07/23/2012

    Millions of people in the developed world thrive on a vegan diet, including sports champions with demanding nutritional requirements.

    Let’s be thankful – and use – science, which allows us to easily get b12 through a pill. (Many non-vegans require b12 supplementation as well.)

    Let us strive for a nonviolent diet.

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  12. 12. smiths37 7:40 pm 07/23/2012

    “we all have the basic machinery to get fruity or nutty without trouble.” Except for those who are allergic to nuts and stone fruits…?

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  13. 13. emmajuneau 7:42 pm 07/23/2012

    a lot of what i have read about “paleo” diets seems to be less about eating tons of meat and more about NOT eating things that humans have mostly only eaten since the advent of agriculture – grains, legumes, refined sugars, fruit juice, large amounts of certain foods, etc. but mostly grains and beans. the idea being (i have NO idea if it’s scientifically sound) that we are not evolved to digest the protective outer layer of seeds/grains and that substances in it inhibit the assimilation of minerals and have an acidifying affect on the body. they don’t point so much to the starches as the problem.

    i would be interested in the author’s opinion specifically on grains and legumes in the human diet as there doesn’t seem to be anything comparable in the diets of monkeys, apes, etc. in general the objections that the paleo people have to food bred for agriculture is glossed over in this article.

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  14. 14. Cramer 7:59 pm 07/23/2012

    Not much was said about our large brains which make us different from other primates. Could we need more meat to meet the nutritional demands of our brain.

    [BTW, I'm a vegetarian who occassionally (a few times per month) eats a small serving of meat.]

    Link to this
  15. 15. tracker1312 8:21 pm 07/23/2012

    First of all, I’m not a monkey. My ancestors may have been at some point, but I am not, nor were many of my ancestors before me for a very long time. You talk about how our guts look similar to other primates, but you mention nothing of biochemistry. Does what we ingest use the same biochemical pathways as they do? Do you know anything of biochemistry? Why are essential fatty acids essential if we don’t need animal fat?

    Second of all, you fail archaeology and anthropology forever. See: Inuit. They eat nothing but meat, very fatty meat. They feed the lean to their dogs. Or they did. Until they started eating western food like wheat and became very sickly people.

    Also see: Paleolithic Middens in Europe and the Middle East. Full of butchered large game. Tons and tons of bones. What is that about no meat? Early humans were excellent hunters. It’s called an atlatl. You should look it up. Or watch videos of African and Australian tribesmen bringing down large game with spears.

    Someone has an agenda. Maybe everyone has an agenda. The least you could do is use some critical thinking skills and get your facts straight.

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  16. 16. BA78 8:56 pm 07/23/2012

    I never imagined such an article could exist that gets every single substantive argument wrong.

    In order to produce an article on this subject, I would recommend an author that has some kind of direct knowledge about anything at all.

    Link to this
  17. 17. American Muse 9:24 pm 07/23/2012

    If you extend this argument to the extreme you could as well say that human ancestors were once all photosynthetic!

    Link to this
  18. 18. geometeer 10:44 pm 07/23/2012

    I am a vegetarian, so I would like this argument to be stronger: but I am amazed that the article completely ignores dentition.
    Our teeth are so clearly a compromise between the needs of herbivores and carnivores that our ancestors must have been omnivorous for a fairly long time.
    Moreover, all foods (plant and flesh) become so different after cooking that any comparative study should use only cooked-food-eating species. Apart from some of our pets, with their evolution massively distorted by human selection, we are the only example.

    Not only is this article weak: there is probably no strong argument in this debate, on any side, that could help us with current dietary problems.

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  19. 19. 12:36 am 07/24/2012

    HA! As always, you crack me up. Great post. I’m inspired to pack a bag of gorp and head off to the Amazon to find me some fungus-laden tropical leaves. Maybe I’ll also munch on some grubs along the way. Yum, yum.

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  20. 20. vage slang 3:36 am 07/24/2012

    I think this article is terrible, at least if you find any differences show us. Gorilla’s have much larger intestines relatively than humans, so when it’s convenient you compare them with us, when it’s not, they are different of course. Why not go back 500 million years ago or even further?

    You did not take a very obvious factor like cooking, a sort of predigesting and even speculate about a trade off between energy investing of the brains and guts.

    It’s very speculative, I would suggest if you speculate, brainstorm, please say so. Instead it implies some thourough investigation on your part, it actually seems that your sources where wikipedia and maybe inspired by some anti meat organization or just wishfull thinking.

    I wonder why scientific america publishes this kind of rubbish, it’s because ofthe readers comments in this article that it is bearable. Scientific? By no means.

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  21. 21. dbyrne4 4:32 am 07/24/2012

    It is funny to see how defensive people get when you mention their meat.

    Meat putrefacts in your long intestine, producing toxins and acid waste which favours the mutation of cells and become carcinogen.

    You are all going to jump and deny that Colon cancer is not linked to meat consumption?

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  22. 22. dadster 5:14 am 07/24/2012

    I thought vegetarianism was a habit picked up by humans, only much later in the evolution and development of the species ,after he learned systematic cultivation and entered the agricultural-age !

    i had Always thought that the cave-man was a hunter-gatherer and,he was built physically strong for hunting animals in wild forests .

    Of course, women were always made emotionally stronger and more intelligent too to make up for muscles and bones and in keeping themselves and their children safe from danger without taking all the physical risks men take in executing efficient hunting of dangerous animals …
    That’s how man became outdoorish and women indoorish. ..
    was, what i thought..till now.

    But if it was all gathering of fruits and nuts that was involved then that could have also been done as efficiently by women as men themselves.

    It’s now becoming increasingly clearer that the differences in the make up of men and women are entirely due to the effects of chromosomal,differences ,the XXs and XYs.

    Have all other species of animals, birds and fish the same chromosomal difference in their genders , have they got the XXs and the YYs or something similar to that ?
    Has the genome of some animals and birds and fish been mapped and analysed ?
    Its a fact that even the males of the bovine species , who are strictly vegetarians are more aggressive than the female of the species.( although a cow can become extremely aggressive if her young calves are threatened by any danger).

    Men’s inherent nature of taking risks ( physical , economic or intellectual ), is the result of chromosomal difference may be there for purposes of procreation of the species ,which is a survival strategy in getting across antagonistic debilitating environments in the grips of the inevitable forces of ‘entropy’ resulting in overall ultimate degeneration and disorganization of the environments.

    Men or other male species had a flare for courting danger , and for courting women ,no less dangerous !
    It’s all nature;hardly has nurture anything to do with it.

    This scientific blog of Rob Dunn , if proved really true , has profound cultural ,psychological and philosophic fall-outs.

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  23. 23. geojellyroll 5:30 am 07/24/2012

    I’m a vegetarian and have been for nearly 30 years. However, most of our ancestors probably stuffed whatever they could into their mouths.

    Longevity wasn’t an issue. Starvation, predation, disease, infection got us before or shortly after we lost our second set of teeth in our early 40′s.

    In contast I want to be active into my 80′s and beyond.

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  24. 24. slothlovechunk 5:38 am 07/24/2012

    @geojellyroll Paleolithic people had better teeth than us. Before agriculture we didn’t really need dentists.

    Check out:

    Link to this
  25. 25. phalaris 7:07 am 07/24/2012

    You get a good perspective on the relevance of this article when you look at the current one on the SciAm page about the polar bears:
    that article makes it clear that the polar bear and the brown bear have different diets, despite being closely related to the point of interbreeding. And even the pandas are much more closely related to brown and polar bears than many of the species mentioned above are to hom. sap., yet they once again, have a completely different, highly specialised, diet (a specific kind of bamboo).

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  26. 26. someguy 9:14 am 07/24/2012

    Obviously the primarily vegetarian diet is far healthier than the burgers and steaks we think we need to eat. The truth is as adults humans need very little protein to be healthy. I get a chuckle from the deniers who say they stay hungry when they don’t eat meat. I really doubt that these people even know what real hunger is, what it feels like and means when there isn’t any food to eat and your body begins to feed on its own muscle and bone marrow. That is real hunger.

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  27. 27. David Marjanović 9:20 am 07/24/2012

    Our ancestors haven’t eaten hummingbirds in a long time! There haven’t been any hummingbirds outside the Americas for about 25 million years.

    You talk about how our guts look similar to other primates, but you mention nothing of biochemistry. Does what we ingest use the same biochemical pathways as they do?

    Yes. Get over it, you are a monkey.

    Second of all, you fail archaeology and anthropology forever. See: Inuit. They eat nothing but meat, very fatty meat. They feed the lean to their dogs. Or they did. Until they started eating western food like wheat and became very sickly people.

    Different people can deal with different food to different extents. The fact that there are people who can practically live on fatty meat alone* doesn’t mean you could – nor does it mean you could necessarily survive on, say, Greek cuisine where everything swims in olive oil.

    Don’t even assume you can necessarily deal with the traditional food of wherever you come from! I eat a lot of fat, my brother immediately gets diarrhea from quite small amounts.

    * Don’t, however, forget stuff like caribou stomach contents.

    If you extend this argument to the extreme you could as well say that human ancestors were once all photosynthetic!

    Not that it matters… but… no. Animals have never had photosynthetic ancestors.

    Meat putrefacts in your long intestine

    ~:-| You’d need to eat a lot of meat for any of it to even reach your large intestine (that’s what you mean, right?) Normally, it’s completely digested in the stomach and the small intestine.

    i had Always thought that the cave-man was a hunter-gatherer

    In modern hunter-gatherer cultures, a lot more gathering happens than hunting!

    That’s how man became outdoorish and women indoorish. ..

    …uh… what?

    Have all other species of animals, birds and fish the same chromosomal difference in their genders , have they got the XXs and the YYs or something similar to that ?
    Has the genome of some animals and birds and fish been mapped and analysed ?

    All placental* and marsupial mammals have XX for females, XY for males. Monotremes have XXXXXXXXXX for females and XYXYXYXYXY for males (five different X and five different Y chromosomes). Birds have ZZ for males and ZW for females! (And the W chromosome is similar to one of the monotreme X ones.) Crocodiles and turtles have no sex chromosomes at all, their sex depends on the temperature of the egg. And so on. There are fish species that are male when they’re young and turn female when they get older… you name it, some animal species has it!

    * With one exception: there’s a rodent species that has lost the Y chromosome, so males are X0. When that happens in humans, it’s called Turner’s syndrome; people with this condition are women.

    Its a fact that even the males of the bovine species , who are strictly vegetarians are more aggressive than the female of the species.

    That’s true, but google for “phalarope”.

    for purposes of procreation of the species

    No, for procreation of the genes that happened to be bundled in the individual in question. Species do not exist in such a sense.

    It’s all nature;hardly has nurture anything to do with it.

    Learn more about nature, and you’ll see that you’ve exaggerated.

    Longevity wasn’t an issue. Starvation, predation, disease, infection got us before or shortly after we lost our second set of teeth in our early 40′s.

    Don’t confuse life expectancy at birth with the life expectancy of someone who had survived all childhood diseases and the other risks of being small or inexperienced.

    a completely different, highly specialised, diet (a specific kind of bamboo)

    supplemented on very rare occasions with bamboo rats.

    Link to this
  28. 28. rcoleman792 9:45 am 07/24/2012

    I personally think it’s hilarious that people are criticizing the scientific merits of this article. In case you haven’t noticed, this isn’t written as a purely scientific publication. It’s simply meant as a casual comparative analysis of the diets of our evolutionary ancestors and us today. Someone mentioned something about biochemistry and someone else just trashed it for no reason at all. It is irrefutable that the diets of most apes and monkeys are mostly plant based. He presents that as fact. Additionally, he doesn’t condemn eating meat at all, he simply criticizes those who suggest that paleo is about eating only meat. As for whoever mentioned dentition, if in fact we were only meant to eat meat (or primarily meat) as these diets suggest, our dentition would be much more similar to a carnivore; we would have much more prominent incisors and would lack teeth necessary for grinding plant matter. As for the biochemistry I would recommend JCI or perhaps Nature publications for a scientific publication on the subject. As for cooking, seriously? If we were to take on the premise that we would eat as our paleo ancestors did, it would be very likely we would not cook our meat at all. That trend is pretty uniquely human (with some exceptions)and therefore one simply cannot compare cooked food to raw food AND include an evolutionary argument. Actually it seems that any paleo argument can be invalidated simply by the notion that our ancestors did not prepare food anywhere near the same degree that we do. So if you cook your meat and your vegetables, you’re probably not actually on a paleo diet. If you eat locally sourced, nutritious food you will be fine. If your longevity is really so important that you would spend inordinate amounts of time researching ancient diets to help you live longer then I would suggest a psychologist and perhaps a look into neurobiology research attempting to upload human consciousness to a computer.

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  29. 29. rootyb 2:08 pm 07/24/2012

    Anyone that thinks that a “paleo” diet is all meat doesn’t really know anything about the paleo diet.

    And of course the author’s science is going to be brought into question; it’s Scientific American, and he’s making rather bold statements and presenting them as fact, based on some rather specious points.

    All of that aside, though, this is just another article on the paleo diet written by someone that doesn’t know anything about it that they haven’t read in other articles written by people that didn’t know anything about it, either.

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  30. 30. sangandongo 3:28 pm 07/24/2012

    Right out of the gate I take exception to this. “Half of all Americans are on a diet…” I have never been on a diet. “…and the other half are on a binge.” I am not doing that either. I am healthy, athletic, active, slim and eat what I want.

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  31. 31. Studious 3:31 pm 07/24/2012

    What was omitted here is that farting is a biological imperative.

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  32. 32. jack.123 7:41 pm 07/24/2012

    I have commented before that it was females that developed agriculture first.In their gathering’s there were many plantings as well.As far as game is concerned women provided most of the protein in our diets.By gathering small game and insects.The hunting of large animals by males was more so for things other than meat.Such as fat,skins,ligament tissue,and bones for tools and marrow.As well as internal organs that provided nutrients that meat alone could not supply.The notion that this article suggests in that the the consumption of meat had little to do with our diets.Nothing could be farther from the truth.The things that make us different from other primates are the eating of large amounts of meat as a percentage of our diets,cooking,and planting for later harvest.And lets not forget the making of complex tools and the use of fire.This has been going on for hundreds of thousands of years and was going on long before we became homo-sapiens.

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  33. 33. cheftang 1:26 am 07/25/2012

    I’m a bit confused by this article; and by all of these backwards-looking diets. I don’t really see the scientific relevance to compare modern-day humans to homo-whatever (sapien, erectus, etc.). “Humankind” in those days were participating daily in evolution, natural selection and a fight for survival. Those whose genes survived were those who were able to reach breeding age quickest and reproduce the fastest. Evolution would have favored those subjects who consumed the best combination of calories to achieve this one (and only) evolutionary goal. Evolution doesn’t “care” about cancer, alzheimer’s or heart disease. These diseases don’t affect the subjects passing their genes onto future generations.
    I think we’re all getting way off base comparing ourselves to those who were living the battle of “survival of the fittest”.
    In my humble opinion, it should be no surprise that many humans “like” to eat meat. I assume it would be likely (if not probable) that the gene for “liking” meat would have found it’s way through the millennia to modern day humans. The gene for sharp teeth (aka incisors) would likely have survived this way as well. (no citation, don’t even check)
    Modern humans need to figure out that we’re not in the state of nature any more. Survival of the fittest no longer applies (in general). If it did, man’s best option would be to eat philly cheesesteaks and pump iron at the gym every day to gain the opportunity to mate with every female possible. And while this still happens in remote parts of the Jersey Shore, it’s not reality.
    The truth is that evolution doesn’t “want” us to live too long… old people absorb resources that younger, breeding members could be using to proliferate our species. That’s why going back in time 5,000+ years makes about as much sense as choosing raw steak kebabs as your “breakfast of champions”.
    Until recently, no animal (and yes, I’m including humans in this generalization) had ever had the ability to break the cycle of “survival of the fittest” (save for teacup chihuahuas). No animal has had the rational ability to research how it’s food affected its health past the window of time when it left its system.
    Humans have that ability. And we don’t know everything yet. Research shows that animal proteins feed cancer cells in rats, and vegetables are good. Nobody has all the answers. And we may never, but one thing we do know is that a Cheetos bag has NEVER been uncovered at a homosapien burial site. Ever.

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  34. 34. durianrider 7:29 am 07/25/2012

    Paleo diet primal diet makes you fat sick and diabetic. Just look at 99% of the paleo primal authors are overweight. The fit looking ones are on HGH & Testosterone injections.

    The time to eat meat is when you look over the fence and salivate at the sight of a poodle walking around.

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  35. 35. David Marjanović 9:33 am 07/25/2012

    I personally think it’s hilarious that people are criticizing the scientific merits of this article. In case you haven’t noticed, this isn’t written as a purely scientific publication.

    So… it’s “not intended as a factual statement”? Is that what you’re saying?

    Are you even serious?

    And that’s before we even get to the point that this is a science blog hosted by Scientific American. Of course we must assume that this post is intended as scientific, as making factual statements.

    As for cooking, seriously? If we were to take on the premise that we would eat as our paleo ancestors did, it would be very likely we would not cook our meat at all.

    We’ve been using fire for close to two million years now. Don’t underestimate the importance of cooking.

    attempting to upload human consciousness to a computer

    How? Consciousness is something the brain does. It’s not a program. (It’s more like an output.)


    Homo sapiens. Two words, italics, capital letter on the first word, and the -s is not the English plural ending.

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  36. 36. HealthHabits 11:06 am 07/25/2012

    The author is neglecting the link between the evolution of the human brain and the human gut..

    The Expensive Tissue Hypothesis contends that the increase in brain size in humans is balanced by an equivalent reduction in the size of the gastro-intestinal tract. In other words, the increased energetic demands of a relatively large brain are balanced by the reduced energy demands of a relatively small gastro-intestinal tract. This relationship also seems to be true in non-human primates.

    The size of the gastro-intestinal tract is dependent on both body size and the quality of the diet. It is argued that humans (and other primates) could not have developed a relatively large brain without also adopting a high quality (ie protein) diet that would have permitted a reduction in the relative size of the gastro-intestinal tract.

    Dietary quality has played a prominent role in theories of human evolution in general and the evolution of the human brain in particular. One of the most memorable of these theories is the ‘Man the Hunter’ (Ardrey, 1961; Washburn and Lancaster, 1968). This theory argued that increasing amounts of meat in the hominid diet lead to increasing levels of cooperation among the males in the hunt, which lead to brain expansion and the associated development of cognition, language and symbolic culture. This hypothesis was fuelled by the realisation that an increase in the apparent consumption of meat correlated with the increase in brain size seen in Homo habilis and Homo erectus. It was also supported by the recognition in the archaeological record of the basic elements of a hunter-gatherer life-style (home bases and food sharing) (Isaac, 1971). Although the rather simplistic reasoning underlying the ‘Man the Hunter’ hypothesis has lost favour in more recent years (eg. Tanner, 1981; Power and Aiello, in press) the importance of a high quality diet, and meat eating in particular, has been a common theme (eg. Foley and Lee, 1991; Leonard and Robertson, 1992, 1994).

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  37. 37. bucketofsquid 12:59 pm 07/25/2012

    I’m surprised at the number of people ranting about this article based on a tiny part of the topics covered. The number one point of the entire article is that humans are not cookie cutter eaters. None of the respondents so far have addressed that point. Almost all of them have insisted that their way is the right way for everyone else on the planet. The simple fact that the vast majority of humans on the planet would eventually starve or die of the effects of malnutrition if we all ate the same means nothing to them.

    Having read up on the “paleolithic diet” I haven’t found any one definition. What they really tend to get down to is don’t eat highly processed “foods”. To come up with an actual healthy diet we would have to look at the gut bacteria of the individual and the dietary patterns of their ancestors. As far as I’m aware no one has ever done that but the list of diets that kill people continues to grow.

    I have yet to find a diet that accounts for the usage rates of nutrients (including all of those listed by the author and those listed by commenters) as compared to usage rates.

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  38. 38. Pugsley 2:40 pm 07/25/2012

    Maybe the best way to evaluate the wide range of human diets would be to examine the differences in longevity and health between various societies and nations. That’s more direct than trying to figure out the healthiest diet from various ancestral species.

    The life expectancy and comparative health of nations is available online. If you were to look into it for patterns such as vegetarianism vs meat-eating, you would find as I did that there’s really no significant differences between the top ten or so healthiest and long-lived nations. The meat-loving Swiss and Australians are about as healthy as the fish, rice and veggie loving residents of Hong Kong and the Japanese. The top ten are about evenly split among different traditional diets.

    Diet just doesn’t matter as much as we would like it to. We WANT diet to be important for health because it’s something we can control individually, unlike the public health measures and hygiene which really do make a difference, but aren’t changeable by humans on their own.

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  39. 39. JohnSColeman 3:21 pm 07/25/2012

    Martin Pickfords work on incisor-molar relationships (Primates (2005) 46:21–32) indicates that most of the other great apes are a more derived species from the Miocene common ancestor when compared to the conservative human condition.

    He also points out that chimps have dental adaptations to consume meat that humans lack.

    This evidence supports the thrust of your article.

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  40. 40. deometer 1:31 am 07/26/2012

    B12 is only naturally available through animal sources. And it plays “a key role in the normal functioning of the brain and nervous system, and for the formation of blood”:

    Also, Rob, you fail to take into account the fact that things like wheat (especially wheat, but other non-wheat GMOs as well) are evolving at a much faster rate than our guts (and the trillion of bacteria) can acclimate (thanks to stuff like the “Green” Revolution – which saw 1000s of hybridizations within the span of mere decades). Triticum aestivum (and its continuing derivatives) is light years away from wild Einkorn wheat, and all the new gluten structures (et al) produced through further cross-breeding wrecks havok on our digestive systems.

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  41. 41. David Marjanović 10:07 am 07/26/2012

    It is argued that humans (and other primates) could not have developed a relatively large brain without also adopting a high quality (ie protein) diet

    How much of this is due to meat, and how much is due to cooking?

    He also points out that chimps have dental adaptations to consume meat that humans lack.

    We have adaptations to eating hard/tough plant matter that chimps lack. Specifically, we have very thick enamel, and all our premolars* look like small molars. This indicates a shift from fruit to tubers.

    Do chimps have any adaptations to eating meat that orang-utans lack?

    * Sometimes called “bicuspids” in English and only English. …But that’s actually the point: the front premolars of chimps have a single cusp, they look like small canines.

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  42. 42. adamcecchini 5:16 pm 07/26/2012

    Just Google – China Cancer Study. If that’s not enough data for you and the moral aspect of eating meat still doesn’t bother you then just put your head back in the sand.

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  43. 43. SteveO 8:25 pm 07/26/2012

    Clever article.

    On the gut bacteria front, when I was in college it wasn’t a meal if it didn’t have a pound of meat, and I must admit I enjoyed the odd bit of raw hamburger. The only time I got sick was when I bought some bad sausage on a meat pizza.

    Same body, 20 years of pisco-lacta-ova-tarianism, and if I get a meat stock based soup, or a “sure its vegetarian” meal with hidden chunks of meat, I’ll be knowing it in a few hours as my digestive system notifies me with a quick run to the toilet.

    I have thought for a while that my poor meat-digestion-aiding bacteria have long since died off, leaving only the veggie loving ones in place and unable to properly digest meat.

    Upshot – consider that in addition to the variables above, our gut bacteria ecology may change in response to environment or diet as well.

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  44. 44. BuckSkinMan 1:12 am 07/27/2012

    Clarifying: first you have to choose what is meant by “primitive diet.” Just pointing out from actual experience (and that of a few native american friends in the Lakota, Ojibwa and Cherokee tribes): small animals and fish are far, far easier to acquire than large game (deer, for example). Primitive humans (at least going back 14,000 years) are recorded to have used snares and other traps to kill small game, and fish traps to catch fish – so meat was probably never hard to come by as is assumed. Contrarily, some choice vegetables (e.g. tubers) are hard to detect and take considerable work to gather in quantity. My bet is that we are omnivores for a reason: being opportunistic hunter/gatherers makes a lot of sense to people who’ve actually tried to find food in the wild. And remember, my friends, beer is fermented long before it ever reaches the large intestine.

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  45. 45. doctordawg 2:43 am 07/27/2012

    Humans eat a combination of meat and veggies and grow stronger. Humans eat virtually nothing but veggies and die of a B vitamin deficiency.

    Case closed.

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  46. 46. David Marjanović 5:37 am 07/27/2012

    I just googled china cancer study. Really… I don’t need to buy a book to know that there is such a thing as too much meat.

    Reason for obesity in America? Food deserts. Supermarkets that do not sell fresh vegetables. People who eat at McDonald’s 3 times a day because they can’t afford anything else.

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  47. 47. jboulet4648 1:42 pm 07/27/2012

    Jj Stanton at wrote a very interesting piece on the evolution of humans and the potential diet changes.

    I do think there is a distinction between amylase needed to digest tuberous vegetables and linking this amylase to agriculture.

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  48. 48. Marcia Malory 6:40 pm 07/28/2012

    It is impossible to compare the food that we eat today with the food that our Paleolithic ancestors ate because the food itself has changed due to natural selection or planned, selective breeding.

    Fruits have higher sugar content. Domestic animals are fatter and subsist on different diets.

    And as has been pointed out, the paleo diet focuses on eliminating grains and legumes – which I doubt very much were eaten by other primates. The paleo diet does include fruit.

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  49. 49. drdswilson 10:55 pm 07/29/2012

    It is hard to know where to begin to point out the errors in this blog. For one the author misrepresents the article on the Neanderthals whose authors explicitly acknowledge the carnivorous nature of this species diet. They are at least partly concerned with the addition of plaants/herbals as a supplement to the meat-eaters diets. And it has been conclusively determined that our ancestors, Paleolithic or otherwise, consumed animal products, meat/fish/etc/, as a significant component of their diet. The blog author might read for starter Human Diet: Its Origin and Evolution by Unger and Teaford. It is simply that the blogger is trying to validate his own vegetarianism? It is thought that the addition of meat and fish, etc., to the hominin diet contributed significantly to the development of the human brain, among other things. While vegetarianism is a perfectly valid approach to the provision of essential nutrients, it does require that one is more knowledgeable about nutrient sources. That said, give our ancestors their due and some USO as well.

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  50. 50. jologflg 5:38 am 07/30/2012

    When I read the title of this article I thought there was going to be new evidence to show that our ancestors (paleolithic homo sapiens, homo neanderthalis, homo erectus, homo habilis) were mostly vegetarian (good luck!). However, the author takes the concept of “human ancestor” back to chimps and apes. Why? That is wrong wrong wong. We should be looking at the latest healthy instance of ourselves for cues, not the earliest possible point at which you can argue that we existed in the form of primates. The basic approach is already wrong, like looking for least common factor when you were tasked with finding the greatest common denominator, the answer you’re going to get is plain wrong. And no, neolithic homo sapiens are not the latest healthy instance of ourselves because that is when our stature and our women’s pelvic depth began to shrink and we started to have dental problems, osteoporosis, cancers, early versions of modern diseases culiminating in today’s depressing health statistics thanks to the worldwide spread of the Standard American Diet (thanks Ancel, ya f^$#). This article is propaganda for vegetarianism, yet another diet experiment based on bad science. It reminds me of the cartoon which vegetarians love to publicize in which a hulking gorilla is asked “oh mister gorilla where do you get your protein?” implying that if a gorilla can get large and fit with vegetables than so can you. Talk about false advertising. Notwithstanding that we have hardly a caecum to speak of nor a giant fermentation vat of a stomach teeming with bacteria to break down cellulose to fatty acids (which is what the gorilla ultimately absorbs), let’s take that cartoon a step further. Upon asking this question to the gorilla, will this hulk of a gorilla A) be able to respond intelligently or B) not even know that what the hairless creature uttered was a question to which it should provide an answer? Answer is B) because the gorilla has one of the lowest brain-to-body-mass ratios in the primate family! Seems like there is a cost to having a large and complicated gut that miraculously transforms cellulose to fatty acids (for the vegetarians reading, it’s a small brain). Herbivores have giant, ph-neutral stomach(s) (promotes bacterial growth) teeming with bacteria to break down cellulose into fatty acids and they are required to graze for hours a day. Why? Because there isn’t a mammalian enzyme on this planet that can break down cellulose. Only bacteria and lots of time can achieve this feat and you need a lot of leaves to meet your energy requirements. In contrast we have small, acidic stomachs (to keep away bacteria) and digestive enzymes (to break down meat) and we feast once or twice a day instead of grazing for hours. In line with the Expensive Tissue hypothesis we are able to quickly and efficiently get large amounts of energy from an energy-dense source so we have surplus to fuel a large brain. On top of our stomachs we also have a small intestine that is shorter than that of herbivores but longer than that of obligate carnivores. All of this pointing to the need of a balanced diet made up of whole, clean animals and vegetables devoid of any significant amount of birdfood (grains) and processed food.

    Don’t go blaming ancient foods for modern diseases. The China Study has been revealed to be vegetarian propaganda and the underlying data of the China Study supports a paleolithic diet. All of the above may be classified as pseudoscience but it’s been pseudoscience since the beginning of Man!

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  51. 51. darwindude 7:48 am 07/30/2012

    I think that most of the people that have changed to a paleolithic or ancestral way of eating would argue that it is not a “diet”, as described in the article. It is a change in lifestyle overall for better health. After eating a proper vegetarian diet and watching my waistline grow, blood work results worsen and overall health deteriorate, I discovered the Paleo approach and have lost 38 pounds, blood work is spot on and feel better than I have since I was in my 20′s. Before making the switch, I read everything I could about the science behind the approach, listed to hundreds of hours of podcast with some leading scientists and doctors on paleolithic nutrition. Good science wins on this one… it is a shame that more people shun it as the ‘caveman diet’ instead of the healthy way of living that it is. We would not be fighting the obesity epidemic that we are. You can thank Ancel Keys for bringing us the low fat, high carb diet!

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  52. 52. marclevesque 11:50 am 07/30/2012

    @David Marjanović

    Consciousness is something the brain does

    Are you implying a cerebral cortex is needed? Is a starfish conscious? Is a hydra? Is just one neuron sufficient? Are neurons even needed? Why?

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  53. 53. thoughthustle 2:16 pm 07/30/2012

    All you’ve done is taken the Paleo/Primal/Ancestral diet framework Applied it to animals that are obviously adapting to different niches than our human ancestors.

    The framework will only get you part way ,any way , the other half , the hard work. Is to actually eat something then , test bio-markers of health.

    You can call me a vegetarian that eats meat or a meat eater the eats vegetation or an omnivore that can eat pretty much anything.

    The Ancestral Ideal is just a starting point to do the real empirical study of which foods make us thrive? leafs? fatty meats? brains? lean or fatty fish? fatty plants? vitamin rich carbs?

    If our recent ancestors ate mostly bark for some reason , was that their Ideal diet for their physiology or pathology?

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  54. 54. HubertB 4:46 pm 07/30/2012

    With the beginning of The Old Stone Age about a million or more years ago, humans no longer needed to follow the diet of the other great apes. While chimps could also sharpen a stick, humans could use a stone knife. That made a change possible in the human diet. The diets could diverge a million years ago.
    The way our ancestors ate over a million years ago has little relationship to the way we should eat today.

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  55. 55. Grumpyoleman 6:46 am 08/2/2012

    We sure as I’m sitting here typing didn’t grow our big brains eating turnips. This article is more vegan BS propaganda.

    In 100 generations on a protein deficient vegan diet, pea-brained man will be back on the savanna scavaging left overs which is likely the vegan goal.

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  56. 56. cheftang 9:07 pm 08/2/2012

    Vegan propaganda? You’re not sane.
    Maybe the meat you’re eating is causing paranoia…
    Who told you a vegan diet is protein deficient? The USDA? Good job trusting that group of clowns. You’re aware of course that your carnivorous diet is lining the coffers of all these jokester, right?

    Truth be told, as long as you have your own insurance and my tax dollars don’t have to pay for your statin drugs when your cholesterol is out of control and your gout medication when your uric acid goes through the roof, eat what you want. It’s a free country.
    But remember, the people telling you that the vegan diet is deficient in protein aren’t doing it to help you live long and prosper; they’re doing it because it benefits them in some way.
    No hard feelings my friend; but please don’t refer to things as “vegan BS propaganda” without bringing up at least one valid point.
    The fact that meat may have helped us “come down from the trees” doesn’t mean that it’s what we should be eating TODAY to live long and healthily.

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  57. 57. Kenny 1:32 am 08/4/2012

    What a suprize, finding this voice of reason;
    (((((34. durianrider
    7:29 am 07/25/2012
    Paleo diet primal diet makes you fat sick and diabetic. Just look at 99% of the paleo primal authors are overweight. The fit looking ones are on HGH & Testosterone injections.

    The time to eat meat is when you look over the fence and salivate at the sight of a poodle walking around.)))))

    Why was it when I posted my experiences with eating vegan and my fitness exploits compared to my results with a primal nutrition program not deemed worthy of discussion on your blog? I do like the poodle comment though; What do vegans feed their cats or dogs?
    Is it because you’re afraid to try a primal program to compare for yourself? I can speak to both because I’ve done both. But for the courtesy of your readers, I’ll repost it here:

    While eating vegan (which I did for several years) I found that weight loss was no problem with my active lifestyle, and my endurance for workouts was excelent, however, recovery times suffered horribly. Always willing to experiment with my diet, I tried the primal philosophy next. Wow! What a difference in recovery times and muscle mass. The free muscle mass would be enough to sell anybody!! Additionally, the ability to be more flexible on mealtimes is nice too. Overweight? Not me. Barely this side of 50yo, minus 25 pounds of muscle mass I weigh what I did running cross country in high school.

    Back on topic to the article: I like how when the rungs are kicked out from the authors article, the fanboys say, “Oh, this was really just an editiorial.” Well, yes is was an editorial, but it didn’t indicate it was an editorial, and it appeared in Scientific American, not Editorial American. This is a little like creating a brand called ‘Organic Goodness’ so you can affix your brand on the package and everyone will assume it’s organic. “But nobody would do that, would they?” Well, Scientific American just did and Paul Newman Organics does it every day.

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  58. 58. David Marjanović 1:07 pm 08/9/2012

    and we started to have dental problems, osteoporosis, cancers, early versions of modern diseases

    Wait, wait, wait. Cancer is universal; it occurs in all multicellular organisms. By no means is it restricted to humans!
    Osteoporosis is caused by too much of some female hormone that mammals in general share.
    How common caries is depends heavily on diet; it definitely did become a lot more common with agriculture. But generally speaking, it’s about as old as teeth; there’s a Cretaceous ichthyosaur with caries.

    we feast once or twice a day instead of grazing for hours

    That differs between cultures. I, for one, like to snack more or less all afternoon long.

    Are you implying a cerebral cortex is needed? Is a starfish conscious? Is a hydra? Is just one neuron sufficient? Are neurons even needed? Why?

    1) Yes. 2) I don’t know; probably not. 3) I don’t know; most likely not. 4) Definitely not. 5) Definitely. 6) Do you happen to have any evidence to the contrary?

    “A blow to a man’s head confuses his thinking; a blow to the foot has no such effect; this cannot be caused by an immortal soul.”
    – Heraclitus, 500 BCE

    What do vegans feed their cats or dogs?

    Feeding a dog a vegan diet seems to be juuuuust possible. Cat? No.

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  59. 59. upload70 2:55 am 10/10/2012

    I doubt a diet consisting of bugs and lizards would make anyone money so won’t be promoted by any experts.

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  60. 60. logisd 8:39 am 10/10/2012

    Interesting article. I ask just one question though, is what our ancestors ate relevant in answering the question what we should eat today ? Give a man or woman a diet centered on flesh, dairy products, and eggs, with some veggies on the side. What do you get ? Preventable diseases including heart disease, erectile dysfunction, diabetes, cancer, osteoporosis, etc. Give a man or woman a well planned diet centered on whole, plant based foods (chili/sandwiches/soups/burritos/muffins/cereals/pasta/sautés/tacos/the list is huge). What do you get ? Health by default, quality of life, no preventable western diseases, and a long life expectancy. Plus a carbon footprint 12-18 times lower than an omnivore. Plus a massive reduction in planetary resources used to produce a meal. Plus not supporting horrific industrial scale animal slaughter. If you don’t know how to eat without animal products, the knowledge is just a few cookbooks away.

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  61. 61. Slavon 2:35 pm 10/26/2012

    Are you shure this a really good pleaser?
    And what about

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  62. 62. Douglas Jack 9:36 pm 11/17/2012

    Rob, Your ‘Human Ancestors’ article helps to refocus ‘Paleolithic-diet’ (Weston Price inspired) folks. There is a certain ‘rough-survivalist’ pathology behind Paleolithic thinkers, which is tied more to constant supposed ‘survival-of-the-fittest’ fear-indoctrination by most supposed academic-research, educational programs & media. Academia & media have lost Socrates’ foundation of ‘dialectic’ (‘both-sides’) exploration of truths through ‘debate’ (French ‘de’ = ‘undo’ + ‘bate’ = ‘the-fight’). Your openness to diverse cultural options based in diverse worldwide histories transcends such competition towards collaborative inquiry.

    When research moves beyond recent colonial ‘worldview-indoctrination’ of 2-dimensional ‘agriculture’ (Latin ‘field’) ‘farms’ (French ‘ferme’ = ‘serf’s contract of servitude to the aristocrat’) by considering the efficiencies of ‘indigenous’ (L ‘self-generating’) humanity’s 3-D Polyculture Orchard, we find amazing abundance in biosphere generated food, materials, water & energy cycles in harmony with nature & physics. Indigenous polyculture (multi-level & cultured diverse foods/materials etc) orchards photosynthesize 92 – 98% of solar energy & convert this into abundance.

    Tree roots descend tens of metres as deep as the canopy into the earth’s substrate to conserve & pump water, mine-minerals & develop nutrient colonies. Polyculture creates cold-spots on the face of the continent drawing warm-moist ocean winds inland where 60% of moisture transfer is through condensation on leaf surfaces. Only 40% of moisture transfer is through rain-snow. In contrast ‘agriculture’ photosynthesizes only 2 – 8% of solar energy, reflecting 90% back into the troposphere where it swirls to push ocean winds away from the continent & causing hurricanes. Agriculture roots descend only centimetres leaving the land lifeless, incapable of storing water & without replenishment of minerals.

    Civilization’s worshipping of agriculture’s false production only take place when debate has been eliminated & institutional subservience keeps untruth alive. After colonial agriculture destroys 3-D biosphere, then the refugees created, being on-the-run are forced to eat the animals which they normally developed collaborative co-existence with. ‘Exogenous’ (L ‘other-generated’) colonial victors write history books to diminish indigenous values as ‘savage’ (L ‘sylva’ = ‘tree’), ‘primitive’ (‘primary’) & unworthy of consideration so as to glorify colonial ‘pioneers’ (L ‘pion’ = ‘pawn’). Our history describes our indigenous victims as nomadic ignoring that we have violently displaced them & destroyed the abundant tree-ecologies upon which all life depends.

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  63. 63. lichenophile 3:59 am 11/27/2012

    This article didn’t address the use of fish by the earliest homo sapiens…Why is this? A paper by Dr. David Braun and colleagues in the June 1, 2010 issue of the Proceedings of the National Academy of Sciences, USA, reports on the historical evidence of a large collection of fish bones near a putative settlement of homo, dated to about 1.95 million years ago, in the Rift Valley of Africa. This is the area from where we humans are thought to have originated., And the fish bones they found had bite marks matching those of human (and not great ape) teeth.

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  64. 64. W. Ying 4:52 am 12/22/2012

    Seeing plants (fruits, leaves, seeds, …) we instinctively try to eat or taste.
    Seeing animals (beasts, reptiles, worms, insects, …), we instinctively scare.

    Here, “instinctively” means according to our ancestors’ successful experiences saved in our DNA.

    Hence, we have to be vegetarians nearly.
    Also, the big populations of China and India explain it.

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  65. 65. W. Ying 9:34 pm 12/22/2012

    Eating meat makes us very happy because of: (1) the chemical components of meat meet closely to what our body needs rather than that we need it in large quantity; (2) the difficulty to obtain it.
    That is why eat meat more makes us unhealthy.
    So, in today’s situation of easily getting the meat, eating it is usually a kind of INVALID (ineffective, bad) happiness.

    (For INVALID happiness, see the 1st article, points 1-3, at

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  66. 66. Slavon 4:45 am 01/12/2013

    Don’t forget to blow your nose gently each time after you finish the procedure. This way you will speed up the cleaning process. Usually patients with neti pot deviated septum , who use neti pots, notice improvement from the first day of their treatment.

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  67. 67. robertsmith 1:28 am 02/27/2013

    Certainly the particular mainly vegetarian diet regime is usually significantly more healthy as opposed to cheese burgers as well as beef.

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  68. 68. Indigoblues 12:30 am 03/6/2013

    Yes! I have used this argument for decades…we evolved to be able to eat almost anything to improve our chances of survival in a variety of circumstances. But just because we can eat something doesn’t mean that a food is necessarily ideal, or even ‘good’ for us…it just means we won’t die today… Great article!

    Lorena Novak Bull, RD

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  69. 69. whirleegig 3:02 pm 03/19/2013

    Meat is not a “rare delicacy” for chimpanzees, our closest modern relative.

    There are no vegetarian primates, they all eat grubs and insects. These meats are valuable sources of the vitamins K2 and B12 that are essential to health in all primates. If you think that insects are too small to be a significant source of nutrition, tell that to the whales who subsist entirely on tiny plankton.

    Phytic acid depletes zinc, iron, magnesium and calcium in humans. It is present in grains, legumes, nuts and seeds. These are the foods that humans should avoid or at least prepare in such a way that phytic acid content is reduced.

    The true test of a diet is whether or not people are healthy on it. I would offer that omnivores, vegetarians and vegans (as long as the supplement B12 and K2) who consume food closest to its natural state (other than those that contain phytic acid) are all likely to be more healthy than people who eat processed commercial foods. The Paleo diet is really more about avoiding the modern processed foods that are poor in nutrition and high in toxins than it is about eating just like some hominid did 2 million years ago.

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  70. 70. whirleegig 4:47 pm 03/19/2013

    “Our ancestors were not at one with nature. Nature tried to kill them and starve them out; they survived anyway, sometimes with more meat, sometimes with less, thanks in part to the ancient flexibility of our guts.”

    What does this mean? Death is natural, isn’t it? Are you suggesting that people don’t die anymore, now that we have good ol’ civiliation to protect us? If you’re positing that hunter-gatherers were barely scraping by, that hypothesis is inconsistent with what anthropologists have found to be true. Hunter-gatherers typically worked half as much as we do and had a lot more time for play.

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  71. 71. tedoymisojos 6:29 pm 03/28/2013

    “Phytic acid depletes zinc, iron, magnesium and calcium in humans. It is present in grains, legumes, nuts and seeds. These are the foods that humans should avoid or at least prepare in such a way that phytic acid content is reduced.”

    But isn’t phytic acid already bound to suck minerals already present in legumes and grains? Also, doesnt soaking and thorough cooking take away most of the anti-nutrients you say are unhealthy? Also aren’t someof those anti-nutrients beneficial against some common diseases, say cancer?

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  72. 72. chanhol 12:59 pm 04/9/2013

    I am rather late to finding this article, but it was quite interesting.

    Somewhere around a decade and a half, to two decades ago, living in San Francisco, I began encountering vegans for the first time. Painting with a broad brush, they tended to be strong feminists and very outspoken. When the topic of ovo-lacto-vegetarians came up, the vegans tended to be very, very angry that “these people” were calling themselves vegetarian, yet eating animal products. In short, the vegans tended to be defensive and, honestly, angry about other people’s diets. Consequently, omnivores often became hostile towards peacefully coexisting ovo-lacto-vegetarians, thanks to the offensive assaults waged by the vegans.

    Oh, how the tables have turned.

    The aggressively defensive omnivores commenting here are over-the-top, to say the least. I suspect that they were sold a bill of goods on their “Paleo diet” and they sure seem like they want nothing more out of life than to be able to continue guiltlessly consuming bacon three times each day. God forbid their wives read this article and have ammunition to use the next time the topic of cutting back the red meat is broached!

    As to all the nutritional experts posting here with vitamin B12 as the hook onto which they are hanging their rhetorical hat, I offer one piece of troubling (to their argument) data, along with the explanation. Vegetarians living on the Indian Subcontinent are rarely deficient in B12, achieving adequate levels through their vegetarian diet. Oops. Interestingly, when those studied immigrated to the United Kingdom, they became B12 deficient. The explanation is simple, though unpleasant: traditional agriculture and food preparation. While B12 is produced in the large intestine (too late in the digestive system for the human host to absorb), the manure used on the crops in the Subcontinent is not often fully washed off before the crops are consumed. Sounds like another interpretation of a “Paleo diet”: go eat $*@#.

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  73. 73. AZBlueVeg 3:10 pm 05/19/2013

    I find it very revealing that those commenting in support of eating large quantities of meat cite no actual sources, no real research, and the only authors mentioned are those who have no medical or science degrees. I find these “paleo-apologists” to be vastly misinformed based on correlations made by people who have no background or training in drawing conclusions from those correlations. As any scientist or statistician will tell you, correlation does not necessarily equal causation.

    A previous commenter noted that he/she did not thrive on a high glycemic carbohydrate diet, but is doing much better on a high fat and high meat diet. I suppose when you eat processed, sugary foods all the time then yes, dumping those simple carbohydrates for meat and fat may show some basic improvements. But that is not from inclusion of meat and fat, it is from the elimination of simple sugars which were previously the majority of the poster’s diet.

    I have one question to ask anyone – ANYONE – here who supports paleo and/or eating “as much meat as you want”. How many of you have actually tried a plant-pased program and felt it was inadequate? Or did you simply jump to paleo so that this pseudo-science would support your continued desire to eat meat?

    Anyone who espouses a meat-based program without having tried a plant-based program is biased and has absolutely no credibility whatsoever. There are two groups of people in our country today – those who change to support the research, and those who change the research to support their views. I think it’s clear where Paleo exists in this specturm.

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  74. 74. Violet81 6:55 am 06/6/2013

    I love reading articles like this; I have been strictly Paleo for five months and have seen results in not only my health, but also with weight loss, muscle definition, even my sleep. Every single time I seem to be suckered into articles like this I find the Author either to be: A- A Vegan/Vegetarian (such as Rob Dunn) or B- A member of the DAA in Australia or I guess USDA in the US. This article seems like to me based purely on emotion. I would love to read more about the Paleo diet from someone that isn’t a Vegan/Vegetarian or someone with an agenda such as Rob Dunn. This article is just “pick and choose” and doesn’t really explain why and how my husband who has been a vegetarian since birth has never felt better in his life after deciding to eat meat with me, not only that but he has also lost a heap of weight (purely anecdotal, but still). If population continues to grow as it currently is I will be quite happy to eat insects if need be, many eastern cultures consider it a delicacy. As for mentioning we should also eat feces? Purely emotive. This article is a complete fallacy; all it does is make my argument stronger.

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  75. 75. comandantemanuel 6:04 pm 07/28/2013

    This blog entry is simply false, ahistorical, and unscientific. Check out this video:

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  76. 76. pointfoward 2:56 pm 08/11/2013

    The author makes a few very serious errors in stating some of his colleague’ work.

    First, prosimians are absolutely NOT carnivores. Have they not heard of the Ida fossil, conclusive proof that our ancestors 47 million years ago ate only plant matter (there are not even bugs in her gut).

    Second, we did not evolve to eat cooked or fermented food. We cooked food in order to be able to eat what our guts couldn’t digest AT ALL.

    Our guts have barely changed, but the guts are not the whole story. To say that we are omnivores and can digest animal products is disingenuous. The health problems created in the liver, pancreas, gall bladder, kidneys etc. and organ stresses throughout all hormone activating bodies is proof that we cannot really ‘digest’ this food. It isn’t just about the gut. We can also eat dirt, sticks and arsenic, and all are still wholly toxic to us.

    We evolved from wholly vegan creatures and have made almost no evolutionary progress from the paleo era until now in our guts.

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  77. 77. tinaposey 4:32 am 08/16/2013

    hope you can visit my blog for details.

    Link to this
  78. 78. JohnFMayer 1:19 am 08/29/2013

    An excellent article, Mr. Dunn, its effectiveness amply seen by the many outraged responses from those who prefer to have their current indulgences unquestioned. I’ll not bother answering your critics, except to say that most of them not only haven’t done their homework but, apparently, argue purely on the strength of received knowledge, true because they’ve always believed it. An example is the comment of edevries: “… there can be quite a difference between a diet with a small amount of animal products and one with none– as the widespread B12 deficiency in human vegans shows.” And just where has that “widespread B12 deficiency in human vegans” been observed, Mr. edevries? B12 deficiency is rather common in the US; I have several patients who require a cyanocobalamin injection once a month. Not a one of them is a vegan, or even a vegetarian. Most B12 deficiency is a digestive problem and has nothing whatever to do with diet. “[T]he researchers found no association between plasma B12 levels and meat, poultry, and fish intake, even though these foods supply the bulk of B12 in the diet. ‘It’s not because people aren’t eating enough meat,’ Tucker said. ‘The vitamin isn’t getting absorbed.’” But I’m glad to see even the most zealous Atkins/Paleo advocates, by and large, have given up that old myth about vegans not getting enough protein.

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  79. 79. DDNNam 9:36 pm 09/15/2013

    No they weren’t. First of all you’re basing your theory upon a theory humans evolved from primates. That still has yet to be proven.

    Second, and probably most importantly, you’re talking like they can’t think, like they’re animals doing whatever comes natural to them.

    Early humans, even if you believe their language to be rudimentary at best, they still had the ability to contemplate, and I seriously doubt, knowing how people tend to think who have the ability to contemplate, to think that they’d eat only plants, scarcely edible plants that may or may not be in abundance.

    Do you realize that Chimpanzees chase down and eat monkeys, hunting them in a cooperative fashion. Something that seems apparent to me in the wild are that carnivores are ridiculously strong and agile while herbivores may be agile, but they’re comparatively weak even to carnivores their own size. Now, here in human world, that’s easily explainable, we are smart enough to survive without needing strength and agility because we utilize the cooperative behavior of our species not just for hunting, but for everything, and we survive because of it.

    Indeed, we have been bread for society for millenia now, and yet still, if a group of us were stuck out in the middle of nowhere, chances are, once we figured that we weren’t going to be rescued, we’re going to figure out a way to survive, baring any unexpected major catastrophes. No other animal is capable of that. This is why we are so weak compared to like-sized wild animals.

    However, herbivores do not have that benefit, and many must even have extra advantages to even hope to remain protected.

    Now, you look at the primates that are most closely related to us, and they eat everything, not just meat or vegetation, but they mostly eat meat, from my understanding.

    To think, even if we evolved, it’s rather infeasible to think that we decided to start eating plants during that transition.

    And really, in the end, I guess one thing consistent about diets that kind of supports your assertion is an all meat diet can cause you to lose weight even when you don’t work out, like lots of weight. I can lose 10 pounds in a weak and a half, go back to a normal carb diet for another two weeks, and only manage to gain about half of it back.

    Another thing is that carbs, while they actually make me feel rather odd since I’ve been consistent and then not consistent with this low-carb diet, they are, by far, more satisfying than meat is. I can eat till I’m full of meat, and never feel fully gratified, always like I’m missing something. This is the problem with meat, it’s just not filling when you don’t have enough carbs. Of course my body gets used to the no-carbs the more consistent I am about it, but it’s a battle.

    And the thing is, eat carbs regularly, and you’ll gain weight, well people like me will gain weight. Another thing is the hunger that results from carbs finally being digested is a lot harder to deal with because then you get all shaky and super hungry. Not so much with a meat diet where you don’t get so shaky so quickly, and while feeling hunger all the time due to no carbs, it also seems to keep my body stable, even when hunger is actually present because the food has been digested.

    Yes, one has less energy due to the lack of a regular supply of sugar, but it’s not less capability, it’s less energetic. As in I don’t feel like I could run a marathon, but at the same time, I not less capable of doing so either.

    In fact, I have found the opposite to seem truer. I feel more energetic with carbs, but I seem to be able to do less because the energy quickly disappears, and I get winded. However, with the low carbs, meat diet, the energy is not felt so readily, but I seem to be able to last longer, and I don’t get winded as quickly.

    I imagine carbs like a sudden fire that quickly consumes it’s fuel and meat like a controlled burn that takes the same fuel and makes it last longer. I’m not going to have the spurts of energy I would with carbs, but I’m not going to tucker out as quickly either.

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  80. 80. DDNNam 9:53 pm 09/15/2013

    Here’s a question for you. You know of the utter success of the all-meat to low-carb diets in helping people lose weight and become healthier over all.

    So why is it soooo important for you vegans to convince everyone that meat is dangerous as a main diet? To this end, you all have fought for measures that increased the price of meat and attempted to control the regular consumer through laws that regulate and make meat more difficult to provide and distribute for the consumer to buy.

    With something so inconsistent as herbivorous and carnivorous comparisons have proven to be, why is it so utterly important to you all that meat be demonized and vilified as a main diet source. It’s like you all don’t even care if you’re actually wrong, all that’s important to you all is that people stop making meat a main part of their diet.

    Diabetes, that epidemic, that isn’t caused by meat. There is a proven correlation between diabetes and carbohydrate intake.

    The proof that meat fats cause heart disease isn’t even quite theory yet because the data is so inconsistent to proving that meat fats are the cause.

    You know what I think. I bet there’s a correlation of heart disease with salt and too many carbohydrates over a too long period of time. I bet the meat fats just get the blame because they happen to play a smaller role that can’t even be played unless there are enough carbohydrates over a long enough period of time to actually make something dangerous happen.

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  81. 81. dinbay 9:47 pm 10/10/2013

    Your mode of describing all in this piece of writing is truly fastidious, all can without difficulty know it, Thanks a lot.

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  82. 82. Killshot 10:37 pm 10/10/2013

    Much of this is utter nonsense and is refutable by hundreds of peer reviewed studies and reviews, many of the them done by Loren Cordain PhD professor at Colorado State for 40 years. When this author was applying for tenure, Dr Cordain was publishing his findings after spending years living with primitive hunter gatherer tribes, studying the anthropologic artifacts of primitive people in all climates, and actually conducting rigorous studies on the effects of “non paleo foods” (grains and non species specific dairy to name a few) on human physiology. This blog would be laughable were it not so scientifically unsound and poorly referenced — but typical for a vegan-biased journal that is still drinking the global warming Koolaid as well. And they want me to subscribe? LOL.

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  83. 83. pslebow 5:55 pm 10/30/2013

    There is so much solid research refuting the current fads such as “paleo” and low carb – anti-legume diets. See nutritionfacts. org where the latest research in food nutrition is presented. (BTW true scientists do not use the verbal style displayed by “killshot” – only those with a vested interest in holding onto a belief regardless of the evidence to the contrary)

    Link to this
  84. 84. shippa7 12:28 pm 11/25/2013

    Ingenuity was likely one of the differences which most likely set us apart from other mammals. Specifically, our ability to prepare food in particular cleaning and cooking.

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  85. 85. TruthInTime 6:22 pm 02/18/2014

    Wouldn’t the best questions be: What should we get used to eating? What foods are, and will continue to be, sustainable in current population of over 7 billion and counting? I think this is a fantastic article that brings us a little closer, along with many additional studies, trials and research, in figuring out what is even possible to thrive on in today’s world.

    I’m seeing lots of scared, meat defensive criticism and closed minded comments down here.

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  86. 86. kevinbrands 1:42 am 02/19/2014

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  87. 87. tdperk 6:07 am 02/25/2014

    “Human Ancestors Were Nearly All Vegetarians”

    Even granted to be true, this is without relevance when considering the “paleo” diet. Our distant ancestors had no particularly large brains to support. Our near ancestors hunt quite successfully, and pass up few opportunities to do so.

    With bigger brains to support with fats and protein, the paleo diet is far more plausible as the best model of what our nearest ancestors ate than is any stripe of vegetarianism.

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  88. 88. tina66 11:06 pm 04/1/2014

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  89. 89. tina66 2:57 am 04/3/2014

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  90. 90. king2014 9:54 am 04/4/2014

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  94. 94. Suzan123 9:17 pm 05/24/2014

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  95. 95. Flogiston 12:48 pm 09/7/2014

    I have not read all of the reactions above, but in my opinion MONEY is the thing that parts us omnivores an veggies. There has been build a major business around meat, and it’s ‘normal’ to have some with every meal.
    Going back to basics, where a farmer has a few cows for milk, and eventually for meat is out of the question, since money paves the way we ‘have’ to go. I’m not a vegetarian, but my spouse is and so I can relate to some of the issues.

    Link to this
  96. 96. colleenkpeltomaa 11:00 am 09/21/2014

    This website is linked to the “GorillaProtein” website. This article puts a needed emphasis on gut biome. Probiotics are popular today and having no adjacent and complementary microbes with our fruits and veggies and meats and grains, plus, taking in account the microbe killing antibiotics we all took as children, would compromise our digestion of these foods it seems.

    The piece of crucial data that needs to be taken into account is what is the ideal base chemistry of the human gut and body? For example, the bodily fluids – the lymph and blood – seek to maintain for themselves and for the internal cells an alkaline chemistry. Perhaps because an alkaline base chemistry enhances the body’s electrical system. In fact, the lymph system gels and eventually fails when overburdened with acid-forming foods.

    Thus, eating a preponderance of ripe uncooked fruits and leafy greens would easily work that alchemy in the body. If ancient grains (for example, einkorn wheat) were slightly germinated before being turned into flour for our yummy breads — or better yet, eaten like sweet raw fruit (including the microbes that assisted the germination process) then we might not experience all the diseases we do today.

    Meat, in my understanding, does contain neurotransmitters as does fruit. The neurotransmitters in meat seem to stimulate sex’ing moreso than those in fruits. Also, the body makes its own proteins from the amino acids provided in fruits (the largest concentration), and then in veggies.

    Another point, raw ripe fruits take less time in proportion to their nutrient value to digest. The rest can be supplemented by nutrient dense leafy greens, such as alfalfa, parsley, dandelion, etc., especially if chewed thoroughly and eaten right out of the local garden…germs and all. Most modern eaters with their current gut ecology would probably — at least initially — feel at dis-ease with this process of change, being mostly acidic in their gut and internal cells. Proceed with caution.

    Of course all this would require mass re-education and a real shift in agriculture. However, this is what tribes in Brazil have been doing for a long time — cultivating their own fruit and nut subsistence forests.

    To end, to support the idea of the need for complementary gut bacteria, I heard a story of a modern meat eater who was dying and he visited a shaman in Alaska, who subsequently told him to go and eat rotted meat. He did so and resolved his dis-ease. Carnivores will also go back the next day and eat their kill, microbes and all. Oh, and let’s not forget that even the lion prefers the fermented foods (possibly alkaline) in the guts of their prey — and the blood (alkaline?) and softer organs — over the muscle meat (which more likely gets eaten the next day), whereas we moderns do just the opposite. The proper protocols for eating herbivores and grains have been long forgotten, and it is now normal for us to prefer an apple fritter to fruit on the tree. That, too, as we have discovered requires its own protocols for proper digestion and Ph balance…alka-seltzer?

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  97. 97. KeriJM 7:20 pm 03/18/2015

    Several people have commented upon the current theory that (along with some obvious genetic mutations) by consuming large amounts of protein our species’ brain size increased over that of other “animals”. I haven’t gone “hunting” down the research on this myself. Has anyone ever read of an explanation as to why other carnivorous predators are not also currently as intelligent as humans? Or why there isn’t even a potential line of another predatorial species that was non-humanoid and perhaps died out for some reason that also displayed intelligence? I know I’m talking science fiction here, but that’s just the point…

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  98. 98. jackierose 1:14 pm 04/6/2015

    Interesting food for thought. I came to this article from a 19-year-old vegan who I am currently instructing on the proper etiquette in the office. She’s a preachy young lady, and some of the senior staff took issue with her uninvited, tactless comments about their lunches. She likes to use the “I pay for your mistakes through my insurance” argument until I pointed out some of her own less-than-stellar activities (young people do tend to overshare). But I digress.

    I don’t doubt that plants are essential to the human condition. In fact, it’s always been the foundation of my diet in whatever capacity. Even now I consume upwards of 9 servings of at least 6 different veggies per day. I was a vegan for about a year (and the proud owner of a Veganomicon) until I was just so tired of being tired that I searched elsewhere.

    A few years ago I decided to reintroduce animals into my diet and to eliminate the grains (I discovered that I had gluten sensitivity and a full-blown soy allergy). It didn’t happen overnight, but I eventually started to feel better and better. I used paleo as a framework, but it was nowhere near the “all meat” diet that most here are suggesting that paleo is. The change really came when I introduced fats back in to my meals–and, oh my–bone broth, that lovely, rich, gelatinous treat that I swear makes my once achy knees move and my skin vibrant. All of a sudden I was thriving, performing well at the gym and jumping out of bed in the morning without an alarm. I do not suggest that my eating plan is indicative of health; I just know that I feel fantastic and my doctor is pleased with my bloodwork. I know that if I have to go back to that vegan diet for the “good of the planet,” I will not survive. Many of us are on that journey to prevent disease and remain active, but how do we know for sure. There is just as much anecdotal evidence of a woman living until 100 on a diet of meat, potatoes, and scotch as there is of a man eating nothing but plants and grains. Was it the activity, stress, environment, or diet–or all of the above? Will we ever know? Do what works for YOU, and for the love of all things holy, stop preaching about your own diets.

    As an aside, my biggest concern isn’t food, but water. It’s a crime that we have to pay $20 for a water filter to reduce nonsense that our gov’t puts in it as a “health” additive, not to mention all of the hormones that can’t be filtered out. Terrifying!

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