Dietary intake of fibre and risk of knee osteoarthritis in two US prospective cohorts

Dai Z, Niu J, Zhang Y, Jacques P, Felson DT · Annals of the Rheumatic Diseases

Two independent cohorts agreeing on a split that is the whole finding. Highest versus lowest quartile of total fibre: symptomatic knee OA OR 0.70 (95% CI 0.52-0.94) in the OAI and 0.39 (95% CI 0.17-0.88) in Framingham, with a significant trend in both (p < 0.03). Total and cereal fibre were also inversely associated with knee pain worsening in the OAI (p trend < 0.02). **Radiographic OA showed no apparent association in either cohort.**

Population

4,051 Osteoarthritis Initiative participants followed 48 months and 971 Framingham Offspring participants followed 9 years

Intervention

Higher baseline dietary fibre intake

Comparator

Lowest quartile of intake

Limitations

Observational, single baseline food-frequency questionnaire, and fibre intake is one of the tightest proxies for overall dietary quality and socioeconomic position there is. Symptomatic OA requires both radiographic change and pain, so an effect on pain alone will appear as an effect on symptomatic OA — which is consistent with the null on radiographic OA. An erratum was published.