Association of dietary intake with joint space narrowing and osteophytosis at the knee in Japanese men and women: the ROAD study.

OBJECTIVE: The objective of the present study is to identify dietary nutrients associated with joint space narrowing (JSN) and osteophytosis at the knee in a population-based cohort of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study. METHODS: From the baseline survey of the ROAD study, 827 participants (305 men and 522 women) in a rural cohort were analyzed. Dietary nutrient intakes for the last month were assessed by a self-administered brief diet history questionnaire. Minimum joint space width (mJSW) and osteophyte area (OPA) in the medial compartment of the knee were measured using a knee osteoarthritis (OA) computer-aided diagnostic system. RESULTS: In men, there were no associations of dietary nutrient intakes with mJSW or OPA. In women, vitamins K, B1, B2, B6, and C were associated with mJSW after adjustment for age, body mass index, and total energy (p < 0.05). Vitamins E, K, B1, B2, niacin, and B6 were significantly associated with OPA (p < 0.05) in women. Vitamins K, B and C may have a protective role against knee OA in women and might lead to disease-modifying treatments. CONCLUSIONS: The present study revealed that low dietary intake of vitamins K, B, and C are associated with JSN and osteophytosis in women.