Short for docosahexaenoic acid. Part of Omega 3 fatty acids found in fatty fish such as mackerel, salmon and sardines. Lack of DHA in the diet can influence brain development and performance as it is a major component of the brain cell membrane and the myelin sheath around each nerve. Studies show diets high in omega 3 fatty acids have a lower incidence of degenerative diseases of the central nervous system, such as multiple sclerosis.