Diet and evolution

 
 
 

We use to think that humans are a good example of environment adaptation but, in fact, we are genetically adapted to the environment… that our ancestors live in!

The profound changes (types of foods, nutrient qualities and lifestyle conditions), that began slowly with the domestication of plants and animals (around 10.000 years ago) and become very fast with the Industrial Revolution (food-processing, among others procedures) have occurred too quickly (on an evolutionary time scale) for the human genome to adapt.

Many of the “diseases of Western civilization” have emerged from this discordance and are, at least, partially attributable to diet: cardiovascular disease or type 2 diabetes, to name some examples.

The balance of dietary Omega-6 and Omega-3 is fundamental in preventing the risk of chronic disease and promoting health, but changes such the animal husbandry (that changed the body fat percentage in cattle) or the industrial processing of oil-seed (that increased the total intake of vegetable fat, with higher concentrations of Omega-6 than Omega-3) have led to a current ratio Omega-6:Omega-3, in the Unites States, of 10:1, whereas in the hunter-gatherer diets this ratio was more balanced and it has been estimated to be between 2:1 and 3:1.

This obvious disequilibrium may predispose to chronic disease.