Objective: To determine the efficacy of fish oil derived (n-3) fatty acid supplementation (3-6 capsules/day) in subjects with rheumatoid arthritis (RA) whose (n-6) fatty acid intake in the background diet was < 10 g/day, compared to olive/corn oil capsule supplement over a 15 week period.
Methods: A placebo controlled, double blind, randomized 15 week study to determine the effect of supplementation on clinical variables in 50 subjects with RA whose background diet was naturally low in (n-6) fatty acids. Fish oil containing 60% (n-3) fatty acids was supplemented at a rate of 40 mg/kg body weight.
Results: Analysis of 9 clinical variables indicated there was a significant difference (p < 0.02) between control and treatment groups. Five subjects in the treatment group and 3 in the control group met the American College of Rheumatology 20% improvement criteria. Dietary supplementation resulted in a significant increase in eicosapentaenoic acid in plasma and monocyte lipids in the supplemented group.
Conclusion: The findings suggest that fish oil supplementation that delivers (n-3) fatty acids at a dose of 40 mg/kg body weight/day, with dietary (n-6) fatty acid intake < 10 g/day in the background diet, results in substantial cellular incorporation of (n-3) fatty acids and improvements in clinical status in patients with RA.