Mediterranean diet and risk of multiple sclerosis: A prospective cohort study

Background and Objectives: Although adherence to the Mediterranean diet has been reported to be inversely associated with risk of neurodegenerative disease, it is uncertain if this dietary pattern also reduces multiple sclerosis (MS) risk. Methods: We analyzed data from 41,428 participants in the Swedish National March Cohort. Dietary intake was assessed at baseline in 1997 using a Food Frequency Questionnaire. The Mediterranean Diet Score was analyzed numerically (range: 0–9) and categorically (low, medium, high adherence). Participants were followed using national registries to identify MS cases. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards models. Results: During a mean follow-up of 17.6 years, we identified 89 incident MS cases. Each one-point increase in the Mediterranean Diet Score was associated with a 14% lower MS risk (HR = 0.86, 95% CI: 0.75–0.99). When stratified by smoking, we found a 26% lower risk among non-smokers (HR = 0.74, 95% CI: 0.61–0.90), while no risk reduction was seen among smokers. In age-stratified analyses, inverse associations were observed in participants aged ⩽ 45 years (HR = 0.77, 95% CI: 0.64–0.93), but not in those aged >45 years. Conclusions: Adherence to the Mediterranean diet was inversely associated with MS risk, supporting its potential neuroprotective role.