Polyunsaturated Oils of Marine and Plant Origins and Their Uses in Clinical Medicine

The two main dietary essential fatty acids (EFAs) are linoleic acid and alpha-linolenic acid (ALA). These two parent fatty acids are metabolized within the body to whar are sometimes called the derived EFAs. The derived EFAs include gamma-linolenic acid (GLA), dihomogammalinolenic acid (DGLA) and arachidonic acid of the n−6 series from linoleic acid, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of the n−3 series from ALA. The traditional teaching is that there is no dietary requirement for the derived EFAs. It is assumed that all the amounts of the derived EFAs that are needed can be formed within the body from linoleic acid and ALA.