The role of antioxidant vitamins in the etiology of rheumatoid arthritis

Abstract

There is evidence that insufficient intake of antioxidants may increase the risk of autoimmune inflammatory diseases, including rheumatoid arthritis (RA). Also, lower plasma concentrations of antioxidant vitamins can be a sign of their heavy expenditure to suppress inflammatory processes in the preclinical stage of RA. This article provides an overview of modern studies that have assessed a relationship between the incidence of RA and serum levels or dietary intake of vitamins A, E, C and beta-carotene. Case-control studies have revealed that α-tocopherol and β-cryptoxanthin have a protective effect and their high plasma levels are associated with the decreased incidence of RA. An inverse relationship has been also found between the dietary intake of carotenoids and vitamin C and the risk of RA. At the same time, larger prospective cohort studies have failed to confirm the relationship between the levels of consumption of the major antioxidant vitamins and the risk of RA. The currently available data on the role of antioxidant vitamins in the development of RA remains controversial. Conceivably, sufficient intake of the vitamins has no self-protective activity against RA, but serves as a marker for a healthier lifestyle that lowers the risk of many diseases, including autoimmune disorders.