Association of dietary magnesium intake with radiographic knee osteoarthritis: results from a population-based study

Qin B, Shi X, Samai PS, Renner JB, Jordan JM, He K · Arthritis Care & Research (Hoboken)

The first population-based analysis to put dietary magnesium against radiographic knee osteoarthritis, and it found an inverse threshold association in Caucasians — the second quintile of intake halved the odds of radiographic knee OA (OR 0.52, 95% CI 0.34-0.79) and higher intake added nothing (p for trend 0.51) — and no significant association in African Americans (p for interaction 0.03), a difference later studies also report and none explains.

Population

Participants in the population-based Johnston County Osteoarthritis Project

Intervention

Higher dietary magnesium intake

Comparator

Lower intake

Limitations

Cross-sectional within a population cohort, diet by food-frequency questionnaire, and magnesium intake tracks closely with wholegrain, nut and vegetable intake — so it is a marker of dietary pattern as much as of a mineral. CDC and NIAMS funded; no financial disclosures.