Dietary polyunsaturated fatty acids can significantly affect many biochemical and physiologic functions that are related to inflammatory, immune, and protective reactions.

The different types of fatty acids can impact on energy metabolism, determine the lipid composition of membranes, and influence eicosanoid synthesis, all of which are relevant to prevention of and recovery from illness.

In this paper, the effects of dietary polyunsaturated fatty acids on membrane composition, membrane-associated enzyme and receptor functions, signal transduction, second messenger, and eicosanoid generation are summarized.

The differential effects of the polyunsaturated fatty acids of the n-6 and n-3 families are reviewed in the context of optimizing levels in diets.