When people are hungry, they tend to eat whatever “food” is available. A million years ago, before
the use of fire or the cultivation and marketing of grains and legumes, hominids in central Africa likely found and ate whatever palatable vegetation was available. Millions of tons of tropical food staples are now cultivated and marketed (for details, click Table 1). Some were likely in the local environment long ago with the abundant edible foliage usually eaten by primates.
Such foods supported the development of human life as they gave a balanced supply of protein, energy and n-3 and n-6 nutrients (for details, click Figure below). The combination also gives more than the current RDA levels of dietary fiber and folate. The omega 3-6 balance scores of the foods predicts a resulting tissue HUFA balance of 35% n-6 in HUFA, which is associated with a low risk for chronic health conditions.
Different food choices came with the development of agriculture 10,000 years ago. Food storage and transport increased as human populations expanded to diverse regions of the world where climate and soil conditions caused certain grain and legume combinations to be dominant food staples in the region. New food technology in the 20th century put seed oils into the food environment for humans more than had ever been available before. This caused a rapid rise in omega-6 nutrients in daily American diets.
We now see that “Western” and “Mediterranean” diets give a higher amount of omega-6 in HUFA than traditional Japanese diets. The consequences of having different ethnic foods with different balances of omega-6 and omega-3 EFA nutrients causes the proportion of omega-6 in tissue HUFA to range from 20% to 85%. This can be measured in a simple finger-tip blood-spot test.
updated August, 2017