Associations between diet quality and knee joint structures, symptoms and systemic abnormalities in people with symptomatic knee osteoarthritis

Ruan G, Yang C, Meng T, Zheng S, Zhang Y, Zhu J, Cen H, Wang Y, Zhu Z, Han W, Tang Y, Liu J, Antony B, Winzenberg T, Wluka AE, Cicuttini F, Ding C · Clinical Nutrition

Diet quality was **not** associated with cartilage volume, cartilage defects, bone marrow lesions, effusion-synovitis volume or OA symptoms. It was associated with greater lower-limb muscle strength (β = 0.66, p = 0.001), fewer depressive symptoms (β = −0.08, p = 0.001) and better quality of life (β = −0.06, p = 0.002) — and among the food groups only the vegetable sub-score reproduced that pattern. The dairy sub-score carried no independent association with anything.

Population

Adults aged 50-79 with symptomatic knee OA, from a randomized trial, followed 24 months with MRI

Intervention

Diet quality by the Australian Recommended Food Score, with vegetable, fruit, grain, dairy, fat and alcohol sub-scores

Comparator

Lower diet-quality score

Limitations

Post-hoc exploratory analysis of a trial cohort, diet measured once at baseline, and the score measures dietary variety rather than any specific nutrient. The positive findings are on outcomes — strength, mood, quality of life — that are especially open to reverse causation.