Debunking season – Debunking “Debunking the Paleo diet” by Christina Warinner

The popularity of the Paleo Diet brings a slew of debunking attempts from dietitians and academics answering the call of their vocation to save the world from the big Paleo Diet debacle.

It motivated evolutionary biologist Marlen Zuk to write a book (see my post) and it apparently motivated Christina Warinner to show up at  a TEDx to offer her own debunking, this time from an archaeological point of view.

Christina presents herself as an Archaeological Scientist who studies the health and dietary history of ancient people using bone chemistry and ancient DNA. She then proceeds to call the Paleo Diet “one of the fastest growing diet fads” that “has no base in archaeological reality”.

Every student of science knows that it is impossible to prove anything with certainty and what scientists do, at the most, is assemble more and less dubious facts to tell a story that will hopefully make sense. This framework should be all the more intuitive when reconstructing historical phenomenon, in this case diet, is at stake. This is the reason no scientist can claim to offer certainty regarding ancient diets, no matter what his professional credits are or how confident he or she sounds.

The first myth that Warinner tries to debunk “as an archaeologist” (just to make sure we didn’t miss the introduction) is that “humans are evolved to eat meat and Paleolithic peoples consumed large quantities of meat”.

She begins by stating: “human has no known anatomical, physiological, or genetic adaptations to meat consumption”.  Even in the contest of a TEDx lecture this is a very bold statement for a scientist to make. In plain language it means that there is not even a controversy that she is aware of about the fact in question. That preposterous, incorrect statement alone would have been sufficient to convince me not to waste any further time on this lecture. I would have left it at that had I not read Paul Jaminet and Richard Nikoley‘s posts, urging their readers to stay for the second, better half. Traversing my way to the second half I had to hear that our digestive track is not adapted to eating meat (could it be that she hadn’t read Aiello and Wheeler 1995 or Milton 1987?) and that we have a generalist dentition with molars that are built to shred fiber and not to cut meat and so on and so forth.

I would have loved to see Peter Ungar’s reaction to her statement regarding dentition. Peter Ungar is The best known teeth expert among current physical anthropologists. His reputation got him a million dollars to build a “Biting Machine” to test the suitability of ancient teeth to handle different types of food. Here is a video (18:50 minute) in which you can see Ungar’s machine and hear him state that unlike our predecessors, our teeth are evolutionary adapted to handle meat. In a 2004 paper he stated with appropriate scientific cautiousness: “meat seems more likely to have been a key tough-food for early Homo than would have USOs “[tubers, M.B]. I would also love to see Mchenry’s reaction to the statement that we have big molars. McHenry developed the Megadontia Quantient and shows that in relative terms our molars are less than half the size of our evolutionary predecessors. I will leave it to you to judge how this state of scientific knowledge regarding teeth and gut can be reconciled with a statement denying any “known anatomical, physiological or genetic adaptation to meat consumption” and specific statement about the inadaptability of our dentition to handle meat.

The lecture continues with arguments of like quality and a straw man here and there. To be fair the lecture does also contains some better quality arguments (regarding the validity of isotopic N15 collagen studies for example), which I do not agree with but  are still presented in a more professional manner.

The second half in which she recommends basically natural and fermented foods make more sense but I couldn’t miss the fact that the word “meat” is not mentioned even once which makes the whole thing looks too legit vegetarian to my taste.

In my forthcoming lecture at AHS13 I intend to present the current state of scientific knowledge regarding Palaeolithic nutrition as I see it. Yes, it is inevitably going to be judged as biased by some but by god I hope that the scientific quality of the presentation will not be as easily dismissible as this one is.

As I said in the previous post, Paleo Diet success can be attributed to more then its intellectual finesse so debunking its scientific basis is of little short term practical consequence but still, one would hope that future scientific critique of its basis be done  in a manner that can contribute to the improvement of its efficacy in the long term.

 

Aiello LC, Wheeler P (1995) The expensive-tissue hypothesis: The brain and the digestive system in human and primate evolution. Current Anthropology 36(2): 199–221.

Milton K (1987) Primate diets and gut morphology: Implications for hominid evolution. In: Harris M, Ross EB, eds. Food and evolution: Toward a theory of 
human food habits. Philadelphia: Temple University. pp 96–116

Ungar P (2004) Dental topography and diets of Australopithecus Afarensis and early Homo. Journal of Human Evolution 4: 605–622.

McHenry HM (2009) Human evolution. In: Ruse M, Travis J, eds. Evolution: The first four billion years. CambridgeMA: Harvard University Press. pp 
256–28

 

 

 

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29 Responses to Debunking season – Debunking “Debunking the Paleo diet” by Christina Warinner

  1. So we developed stone tools for hoeing the veges and opening coconuts?
    Those marrow bones got broken by accident?
    The gall bladder just hung around for no reason?
    The persistence of salicylate intolerance?

    Ninnies.

    • bendor says:

      Yeh there is plenty of evidence to ignore if you choose to.

      • Sometimes I think there’s an ancient gatherer resentment over dependence on hunters behind this sort of thing. People who become vegetarian stop identifying with the hunter-gatherer partnership and start looking for evidence that gatherers alone made (or can save) humanity. Born-again hunters too can be led to to the opposite extreme position. They have more of the nutrition on their side, but really both positions are equally silly; we’re a pretty opportunistic species.

      • bendor says:

        I don’t think its that simple George. Chimpanzees are omnivores in the sense that they also eat meat but can you say that they are opportunistic and therefore not obligatory frugivores? Yes we can metabolise starch even with 2 copies of the salivary amylase gene but does that means that we are fully opportunistic and not obligatory carnivores? The daily time and energy resources it takes to obtain starch in the context of our life history also have to be taken into account. I will expand at AHS13.

  2. Miki

    Thanks for the link, Sir. Killer presentation at AHS12, BTW, in case I never got a chance to say that.

    • bendor says:

      Thanks Richard appreciate it. I have been following your blog for years.

      • That means a lot to me. I know I don’t live up to the standards that would be appropriate with folks like you, Paul and other superstars who pop in.

        Or, maybe y’all do it for other reasons. 🙂

      • bendor says:

        Richard to my taste commonsense, originality, non-conformity and boldness are in short supply nowadays, especially in academic circles, so your blog is like a breath of fresh air even if don’t agree 100% with every post.

  3. “Paleo Diet success can be attributed to more then its intellectual finesse so debunking its scientific basis is of little short term practical consequence”

    That’s the meat, right there. In the end, everyone has to eat just about every day. What to eat should not really be a big mystery and the fact that it is, combined with the state of public health, is prima-facie evidence that “debunking its scientific basis” has gone far astray.

  4. Great post. Have you come across this paper? It’ll be an important arrow in your quiver (metaphor to our hominid past intentional). Karina Fonseca-Azevedo and Suzana Herculano-Houzel. (2012). Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution. PNAS. Let me know if you don’t have access and I’ll email you the PDF. There’s also this one: HILLARD KAPLAN, KIM HILL, JANE LANCASTER, A. MAGDALENA HURTADO. ARTICLE
    A Theory of Human Life History Evolution: Diet, Intelligence, and Longevity. Evolutionary Anthropology. Check out Figure 4. The Human diet looks like the modern day paleo diet. The chimp diet looks like an inverted SAD diet (minus the industrial franken foods)! Talk about regression!

    • bendor says:

      Thanks Aaron. I am aware of both papers. Fonseca-Azevedo really confirms Aiello and Wheeler but for the life of me I don’t see why the cooking hypothesis is so widely accepted among non-archaeologists (it is not so widely accepted among archaeologists). There is no signs of habitual use of fire until quite late in human evolution. Just eating enough fat and some uncooked meat can provide human energetic requirements with very little time investment if large animals are available, which was the case until quite recently, when the megafauna extinction began. Hill and Kapklan are, in my opinion, the smartest anthropologist around and this is a great paper. My reference in one of the previous comments to life history is based largely on this paper.

  5. Miki:

    I’m puzzled as to why anyone in the ancestral health movement would recommend this video…as you point out, it makes a number of trivially false statements, and provides no takeaways that all of us haven’t been saying for many years.

    “For the life of me I don’t see why the cooking hypothesis is so widely accepted among non-archaeologists…” The cooked-tuber hypothesis is popular because Richard Wrangham is good with popular media: he wrote a pop-sci book, and managed to somehow wangle a BBC special, pushing it.

    The advantage of such media, of course, is a. a lack of peer review, and b. an ability to present hypotheticals as fact (Catching Fire is full of “must haves”, meaning “There is no evidence for this but I believe it must have happened this way”), enabled by c. failing to mention the corpus of established facts demonstrating Paleolithic meat consumption.

    JS

    • bendor says:

      Hi JS
      I have combed all of Wrangham’s papers and the book looking for evidence that we couldn’t consume enough raw foods 2.5 million years ago. Couldn’t find any. There is a quote of a German paper regarding German raw foodie women who have difficulty getting pregnant on raw diet but we all know these women are mostly if not exclusively vegans. All the other support for this theory comes from “it would have been better if they cooked” or “must haves” as you say.
      Here is a nice anecdote: After the Russian revolution, the party sent a comisar to the Northeastern coastal part of Russia to open a school for the Chukchis, a kind of “Inuit” Russians (http://en.wikipedia.org/wiki/Chukchis). The school served only cooked food and the comisar describe in a book (unfortunately not translated to English but for some reason translated to Hebrew) how difficult it was for the kids to adjust to the cooked food. In fact one day he woke up to discover they have all escaped. When he found them at their homes, some miles away from school, they all confessed that they ran away because they had to eat some raw meat.
      Go figure

      • “I have combed all of Wrangham’s papers and the book looking for evidence that we couldn’t consume enough raw foods 2.5 million years ago. Couldn’t find any.”

        You have to start with the unshakable a priori assumption that hominins of the time were primarily vegetarian — occasional scavengers at best, who couldn’t possibly have been hunting and killing other animals.

        Unfortunately, the evidence has never supported this hypothesis, and evidence in support of Early Pleistocene hunting continues to accumulate.

        JS

        PS: That’s a fascinating anecdote! I suspect that “raw meat” included organs, marrow, brains, sweetbreads, and other “spare parts” that would not have been served by the “civilized” administrators…making the craving nutritional as well as cultural.

    • ” occasional scavengers at best, who couldn’t possibly have been hunting and killing other animals. ”
      Despite scavenging being rare to non-existent among primates in general. The occasional scavenger hypothesis flies in the face of observed primate behaviour of sophisticated and very succesful hunting of other primates and mammals.
      There are a number of these “debunkings” doing the rounds now they seem to be just good enough to convince those who want to believe that evolutionary eating is a sort of faddish pseudo science diet on a par with the blood type diet.
      Sally Fallon’s was particularly bad.

  6. “There is no signs of habitual use of fire until quite late in human evolution” thanks god someone else has said this I honestly feel like I’m going out of my mind when I read/hear people talking about the importance of fire to our development.
    Many tubers available in Africa can also be eaten raw so there really was no pressing need to cook at all.
    Academics often feel the need to comment on /debunk “popular theories” that infringe on their area, and though she is right that the level of knowledge of the Paleolithic is truly risable among many Paleo authors it is up to resisting her rather poor “debunking”. Do they have quality control at TED?

  7. GT says:

    Some people have difficulty in diffrentiating between heuristics (suboptimal but practical, simple ways of algorithms somehting) and ideologies (containing statements of universal truths). The word “debunking” is only applicable to the second group – ideologies, statements of universal thruths etc. A diet by itself can be found to have good results (fully nutritious, no health worsening) or bad effects – like not supplying enough nutritients, or leading to health problems – but cannot be “debunked”.

    Perhaps she thinks that Paleo diet is like veganism, where the major force for choosing food is the idelology of not hurting animals? Or various relogion based restrictions? For me it looks like for Paleo it’s opposite – the major force being a practical need to improve health, while the “paleo” part being just a set of guiding heuristics of what to do. Although there MAY be a minority of people who choose paleo because of the attractiveness of concept of “going back to the roots”…

    Had she researched the topic she might found if Paleo comes from practical or ideological reasons – I’ll just give you an excerpt from the Art Devanny’s interview:

    “It didn’t begin as a caveman thing. It began as our family experiment that we had to do because my young son became a type-1 diabetic at the age of 2. My wife (also became type 1 diabetic) a few years later. This is an autoimmune disease, quite different from obesity-caused type-2 diabetes. So, I first began to see how we could reduce inflammation. […] Then, we tried to knock down the elevated blood glucose by identifying the foods that caused glucose to spike. […]
    The evolution connection just happened because my anthropology colleagues told me I was eating hunter-gather diet when I talked to them. ”

    http://www.fitnessinanevolutionarydirection.com/2011/06/art-devany-uncensored-part-i.html
    —————————-

    Concerning the myths she tells – many of them have been debunked many years ago. For example the “small wild fruit” myth.

    http://rawfoodsos.com/2011/05/31/wild-and-ancient-fruit/

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  9. Jeremy says:

    Hi Miki. Have you ever publicly described your own way of eating? If not, will you?

    • bendor says:

      I am not sure that I have a “way of eating” beside general Paleo. Plenty of fat (animal and coconut) just because I love it with meat and organs (love liver and brain). Will often eat rice, potatoes or legumes (preferably sprouted). Not sensitive to milk as far as I know so plenty of milk products like sour cream and cheese. Eggs are a favorit. Vegetables and some fruits. Quite boring really.

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  11. Jeremy says:

    Sounds like me. I didn’t know if you had some novel take on things. Cheers.

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  14. Dan says:

    I agree that her argument against any adaptations to eating meat seemed a little bit of a stretch. But I felt that maybe you have overinflated this part of the talk a little and brushed over what else she talks about. I think that a lot of the take home messages she brought up were somewhat sound and consistent with paleo even if she thought she had debunked it. She proved pretty convincingly that our ancient hunter gatherers ate what they could, and that dietary breadth was very important. I read this as emphasising the need for increasing nutrient intake and again this is consistent with a paleo approach which tends to downplay foods that are nutritionally disparate. In the end I felt her conclusions pretty much parralled the current paleo approach for many people. I guess the general public still assume the paleo diet is low carb and even in some cases low fat. .

    • bendor says:

      Dan Hi
      I didn’t mean to go into a detailed point by point critique of her thesis because I din’t think it would be of interest to the public at large and because I intend to address some of the points she raised at the upcoming AHS13 presentation. In any case I do not agree that the actual breadth of the Palaeolithic diet was so important or that it existed in a meaningful way at all. To be honest the second half of the lecture sounded to me more like mother and apple pie than anything else and certainly meaningless in the context of “debunking”.

  15. Lifextension says:

    Miki, I just found your blog. Absolutely LOVE your work. ‘Man the Fat Hunter’ is a brilliant paper.

    Best,
    Anna.