Supporters of the Paleo diet believe that we should consume high amounts of our calories through animal fat and protein, restrict our diet to ‘natural’ foods such as nuts, and vegetables, and eschew ‘modern’ grains like wheat. However, archaeological evidence does not support this model.
Dr Christina Warinner‘s TEDxOU talk has gained over 1 million views on YouTube and provides an excellent comprehensive critique of the academic basis for the Paleo Diet. In summary, the diet has no archaeologically solid backing. The degree to which we are adapted to digesting meat is vastly overestimated in the modern version of the Paleo diet as our digestive tracts and dentition suggest a much more generalist set of adaptations, such as large molars that are not specifically tailored towards carnivorous diets. Furthermore, taphonomic bias (how materials survive or degrade in the archaeological record) adds to this the idea that we ate more meat as bones are much more likely to survive the test of time than any plant material.
The role of geographical and environmental variability is greatly simplified in the diet and pays little regard to the seasonality and availability of certain crops and meats. This would have invariably altered what each group of Paleolithic hunters throughout the world would have eaten. Warriner cites as an example a ‘Paleo breakfast’ from an online source that includes blueberries from New England, avocados from Mexico and eggs from China. How would a paleo hunter-gatherer ever accessed this set of produce?
The globalisation of food is a very recent trend that would not have been available to Paleolithic peoples. While this would no doubt be a nutritious and satiating meal, it would not have been one eaten that was eaten by the affectionately named ‘Grok’. Additionally, Warinner cites the variability of nitrogen stable isotope studies and how the results of these studies are not solid evidence of heavy meat consumption; it is likely that animals and humans simply ate what was available and easily accessible in their immediate environment. There is an extreme element of plasticity in the hominid diet that cannot be rigidly defined by a set of inert genetic rules to live by. The Paleo diet is academically unfounded and essentially erroneous, but that doesn’t necessarily mean it is unhealthy.
Warinner is not alone in her views, The Paleodiet Meets Paloepathology conference held in Santiago de Compostela, Spain in October 2015 gathered researchers from 27 universities and 17 countries to discuss the current research using skeletal biogeochemistry to understand links between mobility, ancient health, and diet. Of the papers presented, Aurora Grandal d’Anglad’s research on dietary study using stable isotopes and DNA supported the idea that fluctuations in climate and variability in an animal’s diet throughout their lifetime is a result of selecting foods that are opportunistically available and down to geographical availability. Consequently, there are serious implications for human paleodietary analysis. The role of the individual and cultural selection of foods played a large role in what people were eating.
In future posts I will consider the impact of individual and social selection of foods and behavioural adaptations throughout human history and how this has shaped our own ability to digest and respond to different types of diet in view of our genetic heritage.