The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic
L Cordain, SB Eaton, J Brand Miller, N Mann and K Hill
Here’s the abstract:
Objective: Field studies of twentieth century hunter-gathers (HG) showed them to be generally free of the signs and symptoms of cardiovascular disease (CVD). Consequently, the characterization of HG diets may have important implications in designing therapeutic diets that reduce the risk for CVD in Westernized societies. Based upon limited ethnographic data (n¼58HG societies) and a single quantitative dietary study, it has been commonly inferred that gathered plant foods provided the dominant energy source in HG diets.
Method and Results: In this review we have analyzed the 13 known quantitative dietary studies of HG and demonstrate that animal food actually provided the dominant (65%) energy source, while gathered plant foods comprised the remainder (35%). This data is consistent with a more recent, comprehensive review of the entire ethnographic data (n ¼229HG societies) that showed the mean subsistence dependence upon gathered plant foods was 32%, whereas it was 68% for animal foods. Other evidence, including isotopic analyses of Paleolithic hominid collagen tissue, reductions in hominid gut size, low activity levels of certain enzymes, and optimal foraging data all point toward a long history of meat-based diets in our species. Because increasing meat consumption in Western diets is frequently associated with increased risk for CVD mortality, it is seemingly paradoxical that HG societies, who consume the majority of their energy from animal food, have been shown to be relatively free of the signs and symptoms of CVD.
Conclusion: The high reliance upon animal-based foods would not have necessarily elicited unfavorable blood lipid profiles because of the hypolipidemic effects of high dietary protein (19 –35% energy) and the relatively low level of dietary carbohydrate (22 –40% energy). Although fat intake (28 –58% energy) would have been similar to or higher than that found in Western diets, it is likely that important qualitative differences in fat intake, including relatively high levels of MUFA and PUFA and a lower o-6=o-3 fatty acid ratio, would have served to inhibit the development of CVD. Other dietary characteristics including high intakes of antioxidants, fiber, vitamins and phytochemicals along with a low salt intake may have operated synergistically with lifestyle characteristics (more exercise, less stress and no smoking) to further deter the development of CVD.
European Journal of Clinical Nutrition (2002) 56, Suppl 1, S42 – S52. DOI: 10.1038=sj=ejcn=1601353
This is actually the sort of paper I’ve been searching for for quite a while, although there are probably still some problems with it. For one, even “modern” H-G groups can not at all be assumed to be pristine nor representative of past cultures; there are very few, if any, even in the early 20th century that were unaffected by modern western society and its myriad diseases, or even contemporary agriculturalists and their myriad diseases. Second, a great many of these inhabit marginal environments, having been pushed out by agriculturalists from the best land. OTOH, they do control for this somewhat by using paleobiological data that suggest our forebears in other environments had similar dietary profiles. Also, I wonder if CVD isn’t, in some sense, an aging disease somewhat like cancer. For the most part, by the time westerners actually feel the results of CVD they’re already past the age at which most HGs would have normally lived to.
Still, I like this. It goes along with some other work recently questioning the low-fat low-meat diet that is supposed to protect us all from heart disease. Opinion around the northwest is that local marine-oriented groups had up to 85% of their diet from marine animal resources and there doesn’t seem to be any evidence that it was unduly harmful to their health. For my part, I’m starting to think you can eat all the bacon cheeseburgers you want. . . . just leave off the bun.