Effect of antioxidants on knee cartilage and bone in healthy, middle-aged subjects: a cross-sectional study

Yuanyuan Wang,Anita E Wluka,Graham G Giles,Andrew Forbes,Allison M Hodge,Richard O'Sullivan,Dallas R English,Flavia M Cicuttini

doi:10.1186/ar2225

Abstract

The aim of the present study is to examine the effect of dietary antioxidants on knee structure in a cohort of healthy, middle-aged subjects with no clinical knee osteoarthritis.Two hundred and ninety-three healthy adults (mean age = 58.0 years, standard deviation = 5.5) without knee pain or knee injury were selected from an existing community-based cohort. The intake of antioxidant vitamins and food sources by these individuals was estimated from a food frequency questionnaire at baseline. The cartilage volume, bone area, cartilage defects and bone marrow lesions were assessed approximately 10 years later using magnetic resonance imaging.In multivariate analyses, higher vitamin C intake was associated with a reduced risk of bone marrow lesions (odds ratio = 0.50, 95% confidence interval (CI) = 0.29–0.87, P = 0.01) and with a reduction in the tibial plateau bone area (β = -35.5, 95% CI = -68.8 to -2.3, P = 0.04). There was an inverse association between fruit intake and the tibial plateau bone area (β = -27.8, 95% CI = -54.9 to -0.7, P = 0.04) and between fruit intake and the risk of bone marrow lesions (odds ratio = 0.72, 95% CI = 0.52–0.99, P = 0.05). Neither fruit intake nor vitamin C intake was significantly associated with the cartilage volume or cartilage defects. Lutein and zeaxanthin intake was associated with a decreased risk of cartilage defects (odds ratio = 0.71, 95% CI = 0.51–0.99, P = 0.04), and vitamin E intake tended to be positively associated with the tibial plateau bone area (β = 33.7, 95% CI = -3.1 to 70.4, P = 0.07) only after adjusting for vitamin C intake. The β-cryptoxanthin intake was inversely associated with the tibial plateau bone area after adjusting for vitamin E intake (β = -33.2, 95% CI = -63.1 to -3.4, P = 0.03). Intake of vegetables and other carotenoids was not significantly associated with cartilage or bone measures.The present study suggests a beneficial effect of fruit consumption and vitamin C intake as they are associated with a reduction in bone size and the number of bone marrow lesions, both of which are important in the pathogenesis of knee osteoarthritis. While our findings need to be confirmed by longitudinal studies, they highlight the potential of the diet to modify the risk of osteoarthritis.

Highlights

Osteoarthritis (OA) is a disease affecting the whole joint, including the articular cartilage, bone and soft tissues
The present study suggests a beneficial effect of fruit consumption and vitamin C intake as they are associated with a reduction in bone size and the number of bone marrow lesions, both of which are important in the pathogenesis of knee osteoarthritis
There were no significant differences in dietary intakes or other health-related behaviors such as smoking: 60% subjects never smoked in this population versus 57% in the Melbourne Collaborative Cohort Study (MCCS) population

Summary

Introduction

Osteoarthritis (OA) is a disease affecting the whole joint, including the articular cartilage, bone and soft tissues. Vitamin C, vitamin E, and carotenoids are excellent antioxidants that protect cells from damage by oxidants, and whose blood concentrations are primarily determined by dietary intake [5,6]. These antioxidants may have a beneficial effect on joint health. We showed no effect of supplementary vitamin E or dietary antioxidant vitamins on symptoms and progression of disease in knee OA during 2 years [8,9]. No studies have examined the effect of antioxidants on knee cartilage and bone in healthy subjects, prior to symptomatic disease

Objectives

Results

Conclusion