An Anthropological Look Into the Paleo-Diet

An assignment that turned into a short essay for my Anthropology 589 class.

Introduction

Enter any bookstore, grocery store, or natural food store, and you are immediately bombarded with diets that promise weight loss, health benefits, and increased vitality, among other marvels. At the moment, the most popular is the so-called “Paleo” or “Cave Man” diet. Pick up one of these books, and you will be vehemently advised to adopt a diet that increases the consumption of meats and vegetables, while simultaneously eradicating refined grains and dairy products. Interestingly, the paleo-diet fad roots itself in an anthropological and archaeological debate that has lasted for decades.

Researchers have come to the agreement that at a physiological level, the human digestive system has not evolved for several thousand years. From the emergence of Homo sapiens approximately 195,000 years ago, right up until the agricultural revolution approximately 10,000 years ago, our ancestors subsisted on hunting and gathering. In the time since the agricultural revolution, humans have simply not had enough time to adapt to our rapidly altered diets (Eaton & Konner, 1997).

What researchers cannot agree upon, however, is what our Paleolithic ancestors subsisted upon. Archaeological evidence of Paleolithic human remains, as well as studies of modern hunter gatherer societies, both point to the relative consumption of animal and plant foods. However, few researchers agree upon which nutrient source our ancestors relied primarily upon. Some research suggests that our ancestors relied most heavily upon animal-based foods (game and fish meat), citing animal bones found at archaeological sites, as well as modern hunter-gatherer practices (Cordain et. al., 2000). However, other researchers argue that animal-foods only appear more prevalent because of how much longer the remains take to biodegrade. They suggest that a plant-heavy diet makes more sense, citing vitamin and mineral requirements that cannot adequately be acquired through animal-food-based sources (Nestle, M., 2000).

My analysis herein will attempt to impose my own perspective upon the “paleo-diet”, as well as both its benefits and potential risks. As a proponent and tentative follower of the diet, I realize that those who wish to partake in the paleo-diet should do so cautiously, and after substantial research. Additionally, I am aware that no dietary information should be heeded without the affirmation of a registered dietician. This essay is an attempt to make sense of the multitude of information surrounding the hype that the paleo-diet has stimulated.

What did our ancestors eat?

Our ancestors’ dietary practices are the primary point of argument amongst anthropologists and archaeologists. Some cite the diets of primates, stating the likelihood of a predominantly vegetarian diet rich in fruits and high-fiber plants. Gräslund (2005) suggested the consumption of ripe fruits and berries, as well as shoots, leaves, flowers, tubers, bulbs and nuts and seeds. Carnivorous consumption included meat and edible organs, marrow, seafood, insects and eggs. This is not too different from what humans consume presently, though in much greater variety and availability, especially in Western society. The fundamental difference, then, is not necessarily in the kinds of foods we eat, but how we have modified them.

The paleo-diet, while promoting an increase in meat consumption, generally ignores the fact that our hunter-gatherer ancestors did not cultivate meat as we do now. Wild game meat, generally, has a lower fat content and Omega 6 fatty acid content, as well as an increase in Omega 3 fatty acids. This difference is crucial, especially concerning coronary health, as Omega 6 fatty acids are linked to clotting and inflammatory conditions (Simopoulos, 2002).

The biggest difference between what our ancestors ate and the diets of modern humans, is that approximately ¾ of the modern Western diet was inaccessible during the Paleolithic era (Lindenberg, 2012). Cereal grains and wheat foods, for example, were unavailable for human consumption prior to the agricultural revolution, nor were dairy products. According to current archaeological and anthropological knowledge, our Paleolithic ancestors subsisted upon what their environment gave to them readily, rather than what they could reap from it through innovation.

What do we make of the argument that our genes are stuck in the Paleolithic?

One of the reasons why I advocate the paleo-diet is that it makes sense. Humans invented agriculture and animal husbandry; neither practice is natural. Plants do not naturally grow in rows and produce overabundant yields, and ungulates are not naturally friendly toward, nor reliant upon, humans. These modifications have been artificially imposed within the last 10,000 years. Therefore, despite the changes in our food acquisition processes, that human biology would be capable of such drastic adaptation in such a relatively short period is evolutionarily inconceivable.

If used correctly, the paleo-diet can be extremely beneficial. A recent preliminary study concluded that the adoption of the paleo-diet for a period of 17 days showed lower blood pressure levels, lower urinary sodium and calcium secretion, an increase in urinary potassium secretion, and a considerable effect to blood plasma-insulin levels, including increased insulin sensitivity, just to name a few benefits. (Frassetto, Schloetter, Mietus-Snyder, Morris, Sebastian, 2009).

Granted, there are drawbacks to the diet. Every article I have cited, as well as several that I have not, assert that there is insufficient data to conclude whether the dietary habits of our Paleolithic ancestors is an acceptable model for the consumptive practices of modern humans. The majority of the studies that I have read have had relatively small sample sizes. Furthermore, the lack of consensus among experts leaves very little data to otherwise work with; much more research needs to be done on this topic to provide conclusive evidence in either direction.  

Conclusion

Fad diets come and go, and the paleo-diet just happens to be the most recent. However, research suggests that this diet has the possibility of providing modern humans with a basis from which to structure our dietary requirements. Despite conflicting evidence, the paleo-diet shows promise, and should not be so easily disregarded. With more conclusive research done with larger sample groups, I believe that the paleo-diet could move beyond the realm of conjecture, and become a beneficial modification to the traditional Western diet. However, I am not a registered nutritionist (yet) and have no ability to definitively say whether this diet is as good as the hype surrounding it. The roots of the paleo-diet are dug deeply into human evolutionary history, and with some viable research, hopefully it can influence humans’ dietary practices for the better once more.

Author's Note

References

Cordain, L., Miller, J. B., Eaton, S. B., Mann, N., Holt, S. H., & Speth, J. D. (2000). American Society for Clinical Nutrition, 71(3), 682-692. Retrieved from http://ajcn.nutrition.org/content/71/3/682.long

Eaton, S. B., Eaton III, S. B., & Konner, M. J. (1997). Paleolithic nutrition revisited: A twelve-year retrospective on its nature and implications. European Journal of Clinical Nutrition, 51(4), 207-216. doi:10.1038/sj.ejcn.1600389

Frassetto, L. A., Schloetter, M., Mietus-Snyder, M., Morris Jr., R. C., & Sebastian, A. (2009). Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. European Journal of Clinical Nutrition, 63(8), 947-955. Retrieved from http://dx.doi.org/10.1038/ejcn.2009.4

Gräslund, B. (2005). Ways of life and social structure. In Early humans and their world (pp. 136 - 138).

Lindenberg, S. (2012). Paleolithic diets as a model for prevention and treatment of western disease. American Journal of Human Biology, 24(2), 110-115. doi:10.1002/ajhb.22218

Nestle, M. (2000). Paleolithic diets: a sceptical view. British Nutrition Foundation Nutrition Bulletin, 25(1), 43 - 47. doi:10.1046/j.1467-3010.2000.00019.x

Simopoulos, A. P. (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedicine and Pharmacotherapy, 56(8), 365–379. doi:10.1016/S0753-3322(02)00253-6