Ingestion of fish oil fatty acids (omega - 3 fatty acids ) inhibits the formation of arachidonic acid - derived cytokines and leads to production of compounds with diminished biological activity. Beneficial effects of dietary supplementation with fish oil in rheumatoid arthritis have been shown in many controlled trials.
Methods : 43 patients with active rheumatoid arthritis entered in a prospective, double-blind, placebo-controlled clinical trial to recieve either lOgr fish oil daily (treatment group) or corn oil (placebo group). Baseline drugs and usual diet were continued without any changes. Disease variables were evaluated at baseline and after completion of study period.
The changes in disease variables were compared by paired t-tesl in each group. Comparison of the two groups was done by t-test. Functional capacity was compared by Wilcoxon ranks test.
Results : 19 patients in treatment group and 20 patients in placebo group completed the study which lasted eight weeks . In the treatment group, joint pain index decreased from 30±11 at baseline, to 18±11 at the end of study period (P < 0.01). Joint swelling index decreased from 8 ± 4 to 2 ± 4, (P< 0.01), morning stiffness from 87 ± 41 to 24±16 minutes (P < 0.01). In the placebo group the above variable changes were from 19±14 to 25±14 8±8 to 7±6 and 80±71 to 76±75 minutes respectively, which were not significant . The differences between the treatment and placebo groups were significant in joint swelling index (P < 0.05), morning stiffness (P<0.01) and functioal capacity (p< 0.005), the differences in joint pain index and grip strenght did not quite achieve statstical significance. During study period there were no adverese effects with fish oil consumption.
Conclusion : Fish oil supplemention has anti-inflamatory effects in rheumatoid arthritis. Further studies are needed to recommend its long - term usage concomittant with other drugs in all patients