Abstract
We have evidence that dietary fish oil (FO) decreases severity of collagen-induced arthritis (CIA), changes the fatty acid composition of macrophage (Mϕ) membrane phospholipids, decreases Mϕ synthesis of prostaglandins (PGs), changes chemotactic ability of Mϕs, and affects metabolism of acute phase proteins. Gender also has pronounced effects on susceptibility to CIA and Mϕ prostaglandin profiles. The mechanisms by which dietary n-3 fatty acids may act to alleviate symptoms of CIA, as well as interactions of dietary n-3 and n-6 fatty acids and gender are discussed. We suggest that the ability of FO diets to influence favourably the course of chronic inflammatory diseases is mediated via alterations in n-6 fatty acid metabolism and that intrinsic differences in n-6 fatty acid metabolism may account not only for our reported gender differences in incidence and severity of CIA, but also the well-documented sexual dimorphism in immune/inflammatory responses in general.