Docosahexaenoic acid (DHA) is a 22 carbon bond essential fatty with 6 (cis) double bonds. DHA is essential for the growth and functional development of the brain in infants. It is also required for maintenance of normal brain function in adults. The inclusion of plentiful DHA in the diet improves learning ability, whereas deficiencies of DHA are associated with deficits in learning.
DHA is taken up by the brain in preference to other fatty acids. DHA deficiencies are associated with attention deficit hyperactivity disorder, cystic fibrosis, phenylketonuria, unipolar depression, aggressive hostility, and adrenoleukodystrophy. Decreases in DHA in the brain are associated with cognitive decline during aging and with onset of sporadic Alzheimer disease.
DHA has a positive effect on diseases such as hypertension, arthritis, atherosclerosis, depression, adult-onset diabetes mellitus, myocardial infarction, thrombosis, and some cancers.
Supplemental DHA may have anti-inflammatory and immune-modulating activities and may also elevate HDL cholesterol levels. (The good cholesterol)
DHA also lowers triglyceride levels more effectively than EPA as the following study shows.
“A double-blind placebo-controlled study was performed to determine the triglyceride-lowering effect of DHA compared with EPA. In this seven-week study, 234 healthy men were randomly given: DHA in the ethyl ester form at a dose of 3.6 grams daily, the ethyl ester of EPA at 3.l8 grams daily or corn oil at 4 grams daily. Triglycerides decreased by 26% in the DHA group and 21% in the EPA group compared with placebo. Some retro conversion of DHA to EPA was noted, but no significant conversion of EPA to DHA was observed. A slight, but significant, increase in HDL-cholesterol was seen in the DHA group.”