A randomized, double-blind, placebo-controlled study appearing in Annals of the Rheumatic Diseases (2008;67:841-848) looked at the effect omega-3 fatty acids had on disease activity in systemic lupus erythematosus (SLE). The study lasted 24 weeks and the 60 SLE patients were given either omega-3 fatty acid supplement (3g per day) or a placebo. Disease activity was measured using the revised Systemic Lupus Activity Measure (SLAM-R) and the British Isles Lupus Assessment Group index of disease activity SLE (BILAG). Endothelial function was measured using flow-mediated dilation (FMD) of the brachial artery; in other words, the health and suppleness of the cells lining the artery was measured. The level of oxidative stress was also measured. Measurements were taken at baseline, 12 weeks and at 24 weeks.

Supplementation with omega-3 fatty acids improved SLAM-R and BILAG scores, as well as improving oxidative stress measurements. Researchers concluded that low dose supplementation with fish oil has a therapeutic effect on SLE patients.