On 'Catching Fire:' Part 2.1: Implications for Raw-Foodists 1

Links to the rest:
Part 1
Part 2.2
Part 2.3

There are two ways in which Wrangham's book is of special interest to raw-foodists that I am going to examine here. First, and more briefly, I am going to look at his criticisms of raw food diets and offer some responses to them. Second, and much more interesting and important, I am going to discuss some of the implications of the rest of his research for raw foodists and in fact for anyone who is interested in how to make good nutrition choices.

There are things in here that are useful and important for raw-foodists to know, partly because his research puts paid to some of the mythology surrounding raw foods that is often asserted by raw food enthusiasts and discredits the whole movement, and more importantly because, in my opinion, contrary to Wrangham's own conclusions, much of what he has to say argues in favor of raw foods nowadays! I hope you find this as interesting as I do. This book talks about the importance of ease of digestibility. Smaller things are easier to digest. Well, in the same spirit, I'm going to break this Part 2 down into three further subsections: there is simply so much that is interesting that needs to be said, and I suspect that it'll go down better in smaller doses!

Part 2.1 Wrangham's Critique of Raw-Foodists

On the basis of one short-term and one longer-term study of raw food diets, as well as a few anecdotal experiments and 'castaway stories,' Wrangham concludes that humans lack the ability to extract adequate energy solely from raw foods.

The major studies in question are the 'Evo Diet' experiment, where volunteers with dangerously high blood pressure ate a 'chimpanzee diet' for 12 days, improved all their vital statistics but unexpectedly also lost a lot of weight despite eating 'adequate' calories, and the longer-term 'Giessen Study' of German raw-foodists, many of whom had a BMI much lower than average: low enough to cause amenorrhea in around 50% of the female participants. Quoting with approval the conclusion of the study's authors: "a strict raw food diet cannot guarantee an adequate energy supply," and emphasizing the rate of amenorrhea, which he correlates with infertility, he suggests that from an evolutionary perspective, natural selection would have favored humans who ate cooked food and thus had higher fertility rates and better chance of reproduction. He amplifies this point by contrasting the prosperous, relatively sedentary urban lifestyle of these raw-foodists, with year-round access to high-quality fruits and vegetables, with the much more strenuous lifestyle of a Pleistocene hunter-gatherer, and the inevitability for the latter of seasonal shortages, which would have made fertility even less likely. I'll come back to this point, as I think it is important for raw-foodists. In this German study, by the way, some participants were vegan and some were not, and they were from 70% to 100% raw. Interestingly for Wrangham, the low BMI correlated with the higher percentage of raw food consumption: it didn't matter whether the food in question was vegan or not.

Wrangham's main point is to show that cooking food conferred an evolutionary advantage because more calories are available from cooked food than from raw food, universally so. This is one of the most important take-home lessons of the book. However, because this is one of his key points, he somewhat whitewashes raw-foodism, in my opinion (which is understandable, given his focus, but I want to respond anyway)!He frequently mentions later on in the book that humans 'fare poorly on raw diets nowadays,' and other generalizations, which are falsified by his own acknowledgment that the Instinctotherapists with whom he met (and who use none of the blending/processing techniques he cites as essential to making modern raw-food diets work and unavailable prehistorically) were 'lean and healthy.'

I don't want to spend long on contradicting his whitewash because the implications of his study for raw-foodists and eaters in general are much more interesting and important. Probably all of us have met raw-foodists who are thriving, vibrant and full of energy, as well as raw-foodists who are weak and enervated. Multiplying anecdotes isn't all that useful here. (However, I have to wonder what Wrangham would make of Aajonus Vonderplanitz' 'Primal Diet,' which has its practitioners gain excess weight by eating huge amounts of raw animal products as a therapeutic, toxin-mobilizing regimen. I may write here some day about my own excruciating experiment with that diet. Absolutely all raw foods, and (foolish thing for a recovering anorexic to do) I bulked myself up to the biggest I've ever been, by far. And then, living with my husband, I lost the weight eating cooked food. Quite a bizarre exception to Wrangham's rule.) But I digress.

Accepting that his treatment is a whitewash, I want to address just a couple of things. First off, the fact that all the participants of the Evo study lost a significant amount of weight is only slightly suggestive that raw foods induces a caloric deficit. It is not specified that the participants were overweight to begin with, but since all had dangerously high blood pressure, it is likely that many of them were. For that short, 12 day period, a better interpretation would be that the diet evoked a cleansing response in their bodies. It would have been interesting if their 'outputs' had been measured as well: I'm willing to bet that they pooped a lot out!

As for the longer-term Giessen study: first of all, I am not convinced of his equation between amenorrhea and infertility. I am not an expert on this, but I am under the impression that it is possible to ovulate without menstruating. This also brings us into the area of ideology. Wrangham mentions the strength of belief in the diet held by the Germans in the study, and the belief that absence of menstruation correlates with superior health and absence of toxins in the body. He pooh-poohs this, but speaking from personal experience, I can say that it is a very seductive hypothesis. I would suggest that these women may well have allowed themselves to remain very thin to the point of undernourishment because of underlying emotional issues, a fixation with 'purity,' and some distancing from their body. Just because it might be easier to embrace this ideology on a raw food diet, it doesn't mean that it's an inevitable consequence of the diet. (Personal anecdote: I had no periods for the first 4-5 years of being 100% raw, but I had had none for several years earlier either due to being emaciated. I was convinced that this was a good thing, but I had very little sex drive or any other 'juice.' I started menstruating when I built some muscle and went above 100lbs, when I added raw eggs to my raw-plant-based diet and was very physically active. Periods were painless, light and easy, I got a libido, and that was the best I've felt in a long time. (Why oh why did I mess with the Primal Diet and cooked food?…lessons to learn...))

Wrangham concedes that raw-foodists can thrive - 'but only in rich modern environments where they depend on eating exceptionally high-quality foods.' p. 36. The flip side of 'rich modern environments' is foraging in the wild: an area of much fantasy and idealism amongst raw-foodists. His main goal is to show that humans with anatomies like ours could not have survived and evolved eating solely raw foods on the kinds of foods that were available in the Pleistocene. I'll come back to modern raw food diets later, but I believe that his point here is persuasive. In the next section I'll look at this point in more detail and explain why it is important for raw-foodists to understand.

I hope eventually to show how raw-foodists can put aside myths and fantasies about a pristine and fruitful wilderness, and yet find ways to integrate the wilderness into this modern existence.