The effect of omega-3 polyunsaturated fatty acids on arthritic pain: A systematic review

Background & aims Pain is a significant problem in rheumatoid arthritis (RA), and is associated with prostaglandins derived from the omega-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA). The omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to reduce inflammation, with some studies observing clinical improvements in RA. The aim of this systematic review is to investigate the effect of omega-3 PUFAs on arthritic pain. Method A systematic literature review of omega-3 PUFAs and pain associated with RA was performed up to December 2015. Randomised controlled trials (RCTs) investigating the effect of omega-3 PUFAs (> 2 g/d) on patient and/or physician assessment of pain were included. The Cochrane Collaboration’s tool for assessing risk of bias was employed. Data for outcomes of interest were extracted and collated for interpretation. Results Eighteen RCTs published between 1985 and 2013 involving 1143 patients were included. Dosage of omega-3 PUFAs used was 2.1-9.1 g/day, with study durations of 12-52 weeks. Ten studies supported the hypothesis that there is a reduction in patient or physician assessment of pain associated with RA after intake of omega-3 PUFAs. Eight studies found no statistically significant effect of omega-3 PUFAs on arthritic pain. Conclusions Omega-3 PUFAs may have a therapeutic role in decreasing pain associated with RA, with doses of 3-6 g/d appearing to have a greater effect. Due to the limitations identified in studies included in this review, more research is needed to investigate omega-3 PUFAs in larger populations and over extended periods of time.