DHA, or docosahexaenoic acid, is one type of omega-3 fatty acid. This polyunsaturated fatty acid, which is primarily found in fish, may just be the most important of the three types of omega-3 fats because of its role in healthy heart function, visual and neurological development, and the prevention of heart disease, stroke and Alzheimer's. In addition, DHA also acts as an anti-inflammatory agent and skin preserver.
How much you should have: The American Heart Association recommends that health people consume a combined 500 milligrams of DHA and EPA, the other marine omega-3 fatty acid, each day. People with heart disease should get 1 gram of DHA and EPA per day. Women who are pregnant should be careful to consume DHA from low-mercury sources like sardines or shrimp, or algae supplements.