DHA (Docosahexaenoic Acid)
Docahexaenoic acid, or DHA, is a major component of fish oil. It is a long-chain polyunsaturated fatty acid (LCPUFA) of the n-3 or omega-3 type. DHA is an all cis polyunsaturated fatty acid containing 22 carbon atoms and 6 double bonds. DHA is a vital component of the phospholipids of human cellular membranes, especially those in the brain and retina. It is necessary for optimal neural development and visual acuity. DHA is the most abundant omega-3 fatty acid in human breast milk. DHA occurs naturally in the form of triacylglycerols (TAGs).
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is essential for the proper functioning of our brains as adults, and for the development of our nervous system and visual abilities during the first six months of life. Lack of sufficient DHA may be associated with impaired mental and visual functioning as well as attention-deficit hyperactivity disorder (ADHD) in children. Low levels have also been associated with depression and Alzheimer's disease in adults. Our bodies naturally produce some DHA, but in amounts too small and irregular to ensure proper biochemical functioning. Therefore, preformed DHA must be consumed in the diet through foods such as cold water fatty fish or in supplement form in order to assure an adequate supply. Supplemental DHA may lower triglyceride levels and in some, may elevate HDL-cholesterol levels. DHA is vital for normal brain development for the fetus and infant and for the maintenance of normal brain function throughout life. Supplemental DHA may have anti-inflammatory and immune-modulating activities.
DHA's triglyceride-lowering property results from the combined effects of inhibition of lipogenesis and stimulation of fatty acid oxidation. Fatty acid oxidation of eicosapentaenoic (EPA) acid occurs mainly in the mitochondria, while DHA undergoes fatty acid oxidation in the peroxisomes.
DHA is taken up by the brain in preference to other fatty acids and is incorporated into the phospholipids of the cell membranes of brain cells and the retina. DHA-containing phospholipids in the cell membranes of the neurons appear to be necessary for neurite elongation and formation of synapses. DHA-containing phospholipids in these cells are believed to be vital for cell signaling. DHA is the prominent structural fatty acid in the gray matter of the brain and retinal tissues of humans, as well as other animals.