The Chemical Ecology of Human Ingestive Behaviors

Ingested nutrients and nonnutrients are presented as determinants in human evolution. The amount and quality of energy, including fat, various foods supply are important criteria in governing selection. Oxidative stress associated with respiration of energy is a factor in the etiology of dietary diseases, such as cardiovascular disease and cancer, and in aging. Evolutionary trends such as gains in brain and body sizes, greater ingestion of long-chain polyunsaturated fatty acids and cholesterol, heating of fatty food, and greater longevity increased oxidative stress while greater reliance on animals foods and less on plants decreased ingestion of exogenous antioxidants. The hypothesis that selection for nonnutrient ingestive behaviors was a compensatory mechanism for increasing antioxidants is presented within the context of a four-factor model on the origins of human medicine.