Omega-3 fatty acids can benefit patients with rheumatoid arthritis

According to a new review from the UK, increased intakes of marine omega-3 fatty acids can reduce joint swelling and pain in rheumatoid arthritis patients.

This systematic review included 23 randomized controlled trials that took place over the course of 4 to 52 weeks and evaluated the effects of an average daily intake of 3 grams of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – mainly in the form of fish oil supplements – on different aspects of immune responses linked to rheumatoid arthritis (RA) and rheumatoidic disease symptoms (1). A meta-analysis showed that RA patients who received EPA plus DHA experienced statistically significant benefits, such as a reduction in joint swelling and pain, in the duration of morning stiffness and in the use of anti-inflammatory medications in comparison to those who took the placebo. The omega-3 fatty acids decreased the production of inflammatory mediators and promoted the production of less inflammatory and inflammation-resolving molecules.

The researchers commented that the meta-analysis showed significant but only modest beneficial effects, as the effects were not consistently reported in all studies. The reasons for a lack of consistency in the study findings were most likely related to the implemented dose of EPA plus DHA, which was probably too low in some of the studies, and to the small sample size of many of the studies, which in many cases probably limited the ability to identify an effect.

Rheumatoid arthritis is a chronic inflammatory autoimmune disease of the joints and bones, affecting about 1% of adults and is more common in women than in men. Over time it leads to a progressive destruction of cartilage and bone, most likely due to cytokine- and eicosanoid-mediated induction of destructive enzymes. The omega-6 fatty acid arachidonic acid (ARA) is considered to be the major substrate for synthesizing eicosanoids, which are among the most important mediators and regulators of inflammation. Omega-3 fatty acids found in oily fish and fish oils decrease the ARA content of cells involved in immune responses and decrease the production of inflammatory eicosanoids from ARA.

1. Miles E. A. and Calder P. C. Influence of marine n-3 polyunsaturated fatty acids on immune function and a systematic review of their effects on clinical outcomes in rheumatoid arthritis. British Journal of Nutrition. 2012; 107:171–184.