EPA (Eicosapentaenoic acid)
Eicosapentaenoic acid (EPA) is one of several omega-3 fatty acids used by the body. Our main dietary sources of EPA are cold water fish such as wild salmon. Increased intake of EPA has been shown to be beneficial in coronary heart disease, high blood pressure, and inflammatory disorders.

DHA (Docosahexaenoic acid)
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is essential for the proper functioning of our brains as adults. 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.
DHA is also important to brain and vision development in infants.

Omega-3 fatty acids fall into two major categories: Plant derived (flax seed oil, yielding alpha linolenic acid or ALA) or marine derived (fish oil, yielding both EPA and DHA). The human conversion of ALA to EPA and DHA is inefficient and can be inhibited by various conditions such as a diet high in linoleic acid (Omega-6), trans-fatty acids such as fast foods and baked goods, alcohol intake, certain health conditions, and vitamin and mineral deficiencies (B3, B6, C, zinc, magnesium). Fish, on the other hand, is a direct source of EPA and DHA. The general consensus is that only about 15% of ALA converts to EPA, and it may not convert to DHA at all.