Nordic diet and chronic disease: a GRADE-assessed systematic review and meta-analysis of prospective cohorts and...

This study aimed to evaluate the association between adherence to the Nordic diet and risks of mortality, chronic disease incidence, and cardiometabolic markers, using a GRADE-assessed systematic review and dose-response meta-analysis of prospective cohort studies and randomized controlled trials (RCTs).

We conducted a comprehensive systematic review and meta-analysis, searching PubMed, Scopus, and ISI Web of Science through April 10, 2025. Our analysis included 32 prospective cohort studies and 15 RCTs examining Nordic diet adherence and health outcomes. We calculated pooled relative risks (RRs) and weighted mean differences using random-effects or fixed-effects models, assessed heterogeneity with Cochran's Q test and I² statistics.

In prospective cohort studies, individuals with higher adherence to the Nordic dietary pattern had lower risks of all-cause mortality (RR 0.78, 95% confidence interval [CI] 0.71-0.86), cardiovascular mortality (RR 0.84, 95% CI 0.79-0.80), cancer mortality (RR 0.86, 95% CI 0.81-0.91), and other-cause mortality (RR 0.69, 95% CI 0.60-0.79) compared to those with lower adherence. Similarly, higher adherence was associated with reduced incidence of type 2 diabetes (12% lower risk), cardiovascular disease (8%), coronary heart disease (11%), stroke (12%), and cancer (16%). In RCTs, participants assigned to the Nordic diet showed significant improvements in fasting glucose, insulin, lipids, and blood pressure compared to control diets. However, no effects were observed for high-density lipoprotein cholesterol, apolipoprotein A1, or C-reactive protein.

This comprehensive analysis demonstrates that the Nordic diet significantly reduces mortality risk and the incidence of chronic diseases while improving cardiometabolic markers.