Omega-3 fatty acids are fats commonly found in plants and marine life.
Two types are plentiful in oily fish:
Eicosapentaenoic acid (EPA): The best-known omega-3 fatty acid, EPA helps the body synthesize chemicals involved in blood clotting and inflammation (prostaglandin-3, thromboxane-2, and leukotriene-5). Fish obtain EPA from the algae that they eat.
Docosahexaenoic acid (DHA): In humans, this omega-3 fatty acid is a key part of sperm, the retina, a part of the eye, and the cerebral cortex, a part of the brain.
DHA is present throughout the body, especially in the brain, the eyes and the heart. It is also present in breast milk.