Dietary n-3 fatty acids and therapy for rheumatoid arthritis.
OBJECTIVE
To examine the potential for dietary n-3 fats to be component of therapy for rheumatoid arthritis (RA).


METHODS
Studies of encapsulated fish oil use in RA were reviewed and critiqued, and possible biochemical mechanisms for fish oil effects were examined. The potential for use of n-3 fats was evaluated within a dietary framework rather than a quasi-pharmaceutical framework.


RESULTS
There is consistent evidence from double-blind, placebo-controlled clinical trials that dietary 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 polyunsaturated fat diets and concurrent antiinflammatory drug use. Mechanisms for the clinical effects of n-3 fats in RA may involve their ability to suppress production of inflammatory mediators, including n-6 eicosanoids and proinflammatory cytokines. Suppression of n-6 eicosanoid and cytokine production will be possible using foodstuffs that are rich in n-3 fats and poor in n-6 fats.


CONCLUSIONS
There are many overlapping biochemical effects of n-3 fatty acids and antiinflammatory pharmaceuticals that could explain the clinical actions of n-3 fats in RA. They suggest that there is the potential for complementarity between drug therapy and dietary choices that increase intake of n-3 fats and decrease intake of n-6 fats. In particular, there is the potential for drug-sparing effects. Future studies with n-3 fats in RA need to address the fat composition of the background diet and the issue of concurrent drug use.
James
M J
MJ
Rheumatology Unit, Royal Adelaide Hospital, Australia.
Cleland
L G
LG
D001172:Arthritis, Rheumatoid / Q000178:diet therapy* / Q000188:drug therapy*; D004042:Dietary Fats, Unsaturated / Q000378:metabolism / Q000627:therapeutic use*; D019587:Dietary Supplements; D004311:Double-Blind Method; D015525:Fatty Acids, Omega-3 / Q000378:metabolism / Q000627:therapeutic use*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000378:metabolism / Q000627:therapeutic use; D005260:Female; D005395:Fish Oils / Q000627:therapeutic use; D006801:Humans; D008297:Male; D010919:Placebos
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D010919:Placebos