Abstract

The two main dietary essential fatty acids (EFAs) are linoleic acid of the n-6 series and alpha-linolenic acid (ALA) of the n-3 series. They are metabolised within the body by a sequence of reactions. In turn, several of the fatty acids in this sequence, notably dihomo-gamma-linolenic-acid (DGLA), arachidonic acid and eicosapentaenoic acid (EPA) can give rise to a wide range of short-lived metabolites known collectively as the eicosanoids. The EFAs and the eicosanoids play important roles in both the structure and function of every cell in the body. This paper is primarily concerned with the n-6 EFAs although since the n-3 EFAs are metabolised by the same enzyme sequence, much of what is said is relevant to the n-3 pathway also.