DIETARY N-3 FATTY-ACIDS AND THERAPY FOR RHEUMATOID-ARTHRITIS

Objective: To examine the potential for dietary n-3 fats to be compone nts of therapy for rheumatoid arthritis (RA). Methods: Studies of enca psulated fish oil use in RA were reviewed and critiqued, and possible biochemical mechanisms for fish oil effects were examined. The potenti al for use of n-3 fats was evaluated within a dietary framework rather than a quasi-pharmaceutical framework. Results: There is consistent e vidence from double-blind, placebo-controlled clinical trials that die tary n-3 fats, supplied as fish oil, can have beneficial effects in RA . The beneficial effects appear modest, but their size and extent may have been moderated by common trial design factors such as high n-6 po lyunsaturated fat diets and concurrent antiinflammatory drug use. Mech anisms for the clinical effects of n-3 fats in RA may involve their ab ility to suppress production of inflammatory mediators, including n-6 eicosanoids and proinflammatory cytokines. Supression of n-6 eicosanoi d and cytokine production will be possible using foodstuffs that are r ich in n-3 fats and poor in n-6 fats. Conclusions: There are many over lapping biochemical effects of n-3 fatty acids and antiinflammatory ph armaceuticals that could explain the clinical actions of n-3 fats in R A. They suggest that there is the potential for complementarity betwee n drug therapy and dietary choices that increase intake of n-3 fats an d decrease intake of n-6 fats. In particular, there is the potential f or drug-sparing effects. Future studies with n-3 fats in RA need to ad dress the fat composition of the background diet and the issue of conc urrent drug use.