A Gut Lipid Messenger Links Excess Dietary Fat to Dopamine Deficiency

Food as Reward Why does ice cream taste so good? High-fat foods activate a reward circuit in the brain involving dopamine, a neurotransmitter that regulates pleasure. Overconsumption of high-fat foods is thought to dampen this dopamine-induced reward sensation, leading to compensatory consumption of even more high-fat foods. The mechanisms by which dietary fat in the gut “talks” to the dopamine reward circuit are unclear. Tellez et al. (p. 800 ) suggest that an intestinal lipid messenger called oleoylethanolamine (OEA) may play a role—at least in mice. Mice on a high-fat diet had unusually low levels of intestinal OEA and exhibited deficient dopaminergic responses to gut stimulation with high-fat lipids. Infusion of OEA into these mice restored the dopaminergic response, and mice that had been accustomed to a high-fat diet began to eat more low-fat foods.