Effects of dietary supplementation with marine fish oil on leukocyte lipid mediator generation and function in rheumatoid arthritis

Twelve patients with active rheumatoid arthritis supplemented their usual diet with 20 gm of Max‐EPA fish oil, daily, for 6 weeks. Following this supplementation, the ratio of arachidonic acid to eicosapentaenoic acid in the patients' neutrophil cellular lipids decreased from 81:1 to 2.7:1, and the mean generation of leukotriene B₄ (with calcium ionophore stimulation) significantly declined by 33%. The mean neutrophil chemotaxis to both leukotriene B₄ and FMLP significantly increased toward the normal range at week 6. The generation of 5‐lipoxygenase products by calcium ionophore‐stimulated monocytes was not significantly suppressed, but a significant decline (37%) in plateletactivating factor generation was noted at week 6. The modulation of these measures of leukocyte inflammatory potential suggests that fish oil supplementation may have an antiinflammatory effect.