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

Yuanyuan Wang¹ , Allison M Hodge² , Anita E Wluka¹^,3 , Dallas R English²^,4 , Graham G Giles² , Richard O'Sullivan⁵ , Andrew Forbes¹ and Flavia M Cicuttini¹

¹Department of Epidemiology and Preventive Medicine, Monash University, Central and Eastern Clinical School, Alfred Hospital, Melbourne, VIC 3004, Australia

²Cancer Epidemiology Centre, The Cancer Council of Victoria, Carlton, VIC 3053, Australia

³Baker Heart Research Institute, Commercial Road, Melbourne, VIC 3004, Australia

⁴School of Population Health, The University of Melbourne, Australia

⁵MRI Unit, Mayne Health Diagnostic Imaging Group, Epworth Hospital, Richmond, VIC 3121, Australia

author email corresponding author email

Arthritis Research & Therapy 2007, 9:R66doi:10.1186/ar2225


Published:	6 July 2007

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.