Nutritional factors and osteoarthritis: recent developments.
PURPOSE OF REVIEW: The role of nutrition and nutritional supplements in the development and progression of osteoarthritis is now a topic of considerable public, industry, and academic interest. This review focuses on how the evidence for a role of nutritional factors or nutritional supplements in the management of knee osteoarthritis has been changed by recent research. RECENT FINDINGS: Recent studies include clinical trials of weight loss and exercise as interventions for osteoarthritis of the knee, the elucidation of mechanisms of oxidative stress on the chondrocyte genome, further study of vitamin C supplementation in an animal with spontaneous osteoarthritis, and further clinical and pharmacodynamic evaluations of glucosamine and chondroitin sulfate. Perplexing findings among these studies include the deleterious effects of vitamin C on osteoarthritis in the Hartley guinea pig, the low levels of glucosamine achieved in serum after an oral dose, recent negative clinical studies of glucosamine, and the heterogeneity of results among glucosamine trials. SUMMARY: With an intensification of research in this field come new clinical and basic science data, sometimes with surprising results. These confirm the considerable potential for a role of nutritional interventions for osteoarthritis, but they emphasize the need for systematic scientific evaluation of the claims made for such products.