DHA stands for docosahexaenoic acid and EPA stands for eicosapentaenoic acid. Both are omega-3 fatty acids found in cold-water fish such as salmon, sardines, herring, mackerel, black cod, and bluefish. A vegetarian source of omega 3 is alpha-linolenic acid (ALA), which the body may convert to EPA and DHA.
DHA and another fatty acid, AA (arachidonic acid) are found naturally in breast milk, but if mothers can’t nurse, their babies are deprived of these nutrients because infants, especially those born prematurely, can’t manufacture enough in their own bodies for optimal brain development. A number of studies have shown that formulas supplemented with DHA and AA enhance visual acuity in babies; intellectual development appears to be better, too.
DHA is an omega-3 fatty acid found in salmon, tuna, and other types of fish. It is in the same family as other omega-3 fatty acids found in plant foods like flax, soy, and walnuts. In the human body, the highest levels of DHA are found in the brain, eyes, and sperm. DHA has been studied for preventing heart attack risk factors such as high cholesterol. However, some research found that DHA may increase levels of “bad” cholesterol. DHA has also been studied for improving brain and eye function, infant development, health during pregnancy, and mental disorders. Low levels of DHA have been linked to a higher risk of some conditions such as attention-deficit hyperactivity disorder (ADHD), Alzheimer’s disease, and depression.
EPA and DHA do different things, so you need them both, especially for the brain. If your goal is reducing cellular inflammation, then you probably need more EPA than DHA. How much more? Probably twice the levels, nonetheless you always cover your bets with omega-3 fatty acids by using both EPA and DHA at the same time.