| Rheumatoid arthritis (RA) is an inflammatory condition characterised by swollen joints, unremitting pain and general malaise. People with RA have a shortened lifespan, compared with the general population, possibly attributable to an increased risk of cardiovascular disease (CVD). The systemic inflammation associated with RA may exacerbate the vascular inflammation present in atherosclerisis and CVD. The long chain N-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibit anti-inflammatory properties, as does the N-6 long chain fatty acid gamma-linolenic acid (GLA). A mechanism for this effect is the increased levels of anti-inflammatory eicosanoid precursors EPA, DHA and dihomogamma-linolenic acid (DGLA, and the decreased availability of the inflammatory eicosanoid arachidonic acid (AA) in cell membranes phospholipid fatty acids. Supplementation with four ratios of EPA+DHA:GLA (4:0, 4:1,4:2 and 4:4 on a weight to weight basis) in 32 healthy women resulted in significantly elevated levels of anti-inflammatory serum phospholipid fatty acids (SPFA), compared with an olive oil placebo. All four ratios significantly increased SPFA levels of EPA and DHA, and significantly decreased SPFA levels of AA, but only the 4:2 and 4:4 ratios significantly increased SPFA levels of DGLA. All ratios significantly reduced serum triacylglycerol (TAG) levels, except for the 4:4 ratio, which attenuated this effect. The beneficial effects of supplementation on blood lipids produced a reduction in the PROCAM measure of myocardial infarction risk, with the 4:2 ratio decreasing this risk substantially. The 4:2 ratio of EPA+DHA:GLA, when given to 25 rheumatiod arthritis patients, produced the same SPFA effects as in the previous trial. Serum lipid levels remained unchanged in this population with initially low-normal lipid levels. Although changes in inflammatory biomarkers were not significant, there were trends towards lower total interleukin-6 and soluble intracellular adhesion molecule levels in the treatment group, compared to the placebo group, and in tumour necrosis factor alpha (TNF-alpha) subjects whose initial TNF-alpha. levels were high. The treatment group showed a significant reduction in number and severity of joint pain at the 0.10 level (p=0.0940). Nine often subjects correctly guessed which supplement they were taking, based on its effects. |
