Nutritional Evolution of Domesticated Plants and Animals

With agriculture, it became possible to select varieties of crops that conformed to our tastes. Table 10.1 gives the result. A primary focus was on increasing yields, with the general result of increasing starch and sometimes sugar, but not protein. Protein often remains the same in absolute terms but decreases percentage-wise because of increase in overall size of the grain which is filled up with carbohydrates. We also have selected for increased palatability, which is to say, less fiber, usually fewer antioxidants, less bitter taste, and more sugar. Vitamins and minerals seem to have decreased in crop plants, on the whole, in part because of the emphasis on yields; but there are striking exceptions such as carrots. While the trends shown in Table 10.1 are valid for staples, traditional diets also typically included bitter herbs, high in anti-oxidants, as seasonings or medicinal teas, little altered from their wild state.

Animals lack starch, sugar, fiber, anti-oxidants, and bitterness. But they do contain fat, and our domesticated animals today are much fattier than their wild ancestors, both genetically and due to how we raise them. For instance, stockyard, grain-fed beef is much fattier than free range cattle, and also less nutritious. Range-fed beef is higher in omega-3 and lower in omega-6 fatty acids than stockyard beef, and the fat typically is yellow from the accumulation of Vitamin A. Domesticated plants apparently were tightly constrained in terms of fat evolution. Some species such as corn do have more fat than primitive varieties or the wild ancestor, but most of our oilseeds and nuts were domesticated from already fatty wild species. The availability of fat in our diet certainly has increased, at least in developed countries, but primarily because of increased fat in animals, and the very large number of oilseeds/nuts that we are able to cultivate on large acreages.

Thus, we now find ourselves in an evolutionary mismatch, but one that we created. By altering our food plants and animals so as to satisfy our formerly adaptive cravings, we have created an environment in which we can indulge said cravings to a degree that is extremely unhealthy.