Fish Oils (Essential Fatty Acids or (EFA's) are fats that are needed by the body but are not manufactured by it and thus must be obtained through your diet.
EFA supplements are usually derived from the oil of cold water fish such as herring and bluefish, and from the oil of seeds of certain plants including rape (canola oil), flax, hemp, borage, evening primrose and black currant. Important EFA's include omega-3's (such as eicosapentaenoic acid (EPA) and docosahexaeonoic acid (DHA) andalpha-linoleic acid, a plant oil-derived EPA/DHA precursor). In the body EFA's act to strengthen cell membranes and promote the growth of muscles and nerves. They are used therapeutically to thin blood, inhibit clotting, improve cholesterol profiles and thus help prevent heart disease. EFA's also have natural anit-inflamatory effects potentially useful in treatment of arthritis, allergies and asthama.