The effects of the Mediterranean diet on rheumatoid arthritis in human – a systematic review

Rheumatoid arthritis (RA) is a progressive autoimmune disease characterised by severely swollen and painful joints being presently without a cure. Lifelong treatment, involving pharmacotherapies is often required, risking substantial side effects. Frequently, sufferers request dietary interventions including Mediterranean diet (MD) to help manage their disease. The aim of this study was to determine the effects of MD on prevention and symptom management of RA. A systematic review was undertaken following PRISMA guidelines, using four electronic databases (PubMed, Scopus, CINAHL and the Cochrane Database). A search strategy was formulated to select randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective cohort studies, and nested case–control studies, investigating the effects of MD on the development and management of RA in humans. Outcome measures included results of pain Visual Analogue Scale (VAS), Physical Function Index (HAQ) and Disease Activity Index (DAS28). In total, 1080 studies were identified, with five (three intervention; two prospective) meeting the inclusion criteria. Two intervention studies reported a significant improvement in pain VAS when compared with the control (P < 0.05) and a decrease in HAQ score for the MD group (P < 0.05). Additionally, two studies reported a significant reduction in the DAS28 score for the MD group (P < 0.05). The included prospective studies reported no significant association between MD and development of RA. There is currently insufficient evidence to support the use of MD for the prevention of RA. Nevertheless, MD in conjunction with medical interventions has demonstrated beneficial effects in reducing pain and increasing physical function in RA affected individuals