Omega-3 fatty acids are a group of polyunsaturated fatty acids that play a variety of important roles in health. EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are two of the most important omega-3 fatty acids, and they are commonly found together in seafood and in fish oil supplements.
While DHA and EPA most often function together, DHA plays a starring role in several crucial areas. DHA has a longer carbon chain and a higher degree of unsaturation, which gives it unique structural and functional properties in cell membrane phospholipids, particularly those in the retina and the neuronal synapses in the brain.