Mediterranean diet and knee osteoarthritis outcomes: A longitudinal cohort study

Veronese N, Koyanagi A, Stubbs B, et al. · Clinical Nutrition

Highest versus lowest Mediterranean-diet adherence was associated with a 9% lower risk of incident symptomatic knee OA (RR 0.91, 95% CI 0.82-0.998, p = 0.048) and marginally less pain worsening (RR 0.96, 95% CI 0.91-0.999, p = 0.047) over 4 years — statistically fragile margins in both cases. Incident radiographic osteoarthritis, the one structural endpoint, showed no association. So what moved was the symptom half of a definition that requires both a painful knee and a radiograph.

Population

Adults with or at risk of knee OA (Osteoarthritis Initiative), 4-year follow-up

Intervention

Adherence to Mediterranean diet (aMED quintiles, observational)

Limitations

Observational; both confidence intervals stop at 0.998 and 0.999; residual confounding by weight, activity and socioeconomic status plausible, and the paper's own baseline table shows the top adherence group was less obese, less depressed, more active, more educated and on fewer medications than the bottom. Diet came from a food questionnaire and medications and comorbidities were self-reported. Everyone in the cohort already had knee osteoarthritis or was at high risk of it. The Osteoarthritis Initiative is a public-private partnership: NIH-funded, with Merck, Novartis, GlaxoSmithKline and Pfizer among its private partners.