Does diet have a role in the aetiology of rheumatoid arthritis?

Although dietary factors have been extensively studied in many chronic diseases, the role of diet in the epidemiology of rheumatoid arthritis (RA) has received little attention. Fruit and vegetables and dietary antioxidants are thought to play a protective role in the pathogenesis of CVD and some cancers, but few studies have investigated these dietary components in the aetiology of RA. Fish oil supplementation has consistently been shown to have a beneficial effect on the symptoms of established RA, but it is not known whether the PUFA present in fish oils can reduce the risk of developing the disease. There is evidence that RA is less severe in the southern Mediterranean countries, such as Italy and Greece, where oil-rich fish, fruit, vegetables and olive oil are consumed in greater amounts than in many other countries. Overall, the evidence for a role of diet in the aetiology of RA is limited to a small number of observational studies of very different designs. Recently, it was demonstrated that lower intakes of fruit and vegetables and dietary vitamin C are associated with an increased risk of developing inflammatory polyarthritis in a free-living population in Norfolk, UK. These findings provide further evidence for a role of diet in the development of inflammatory arthritis, although the mechanisms involved are uncertain.