Association of a traditional Mediterranean diet and non-Mediterranean dietary scores with all-cause and cause-specific mortality: prospective findings from the Moli-sani Study

Purpose: To evaluate in an Italian general population, the association with mortality of a traditional Mediterranean diet (MD) and non-Mediterranean dietary (non-MD) patterns, and their combined effect, and to test some biomarkers of cardiovascular (CVD) risk as potential mediators of such associations.

Methods: Longitudinal analysis on 22,849 men and women aged ≥ 35 years, recruited in the Moli-sani Study (2005-2010), followed up for 8.2 years (median). The MD was assessed by the Mediterranean diet score (MDS). The Dietary Approaches to Stop Hypertension (DASH), the Palaeolithic diet, and the Nordic diet were chosen as reportedly healthy non-MD patterns. Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated by multivariable Cox regression.

Results: Participants reaching higher MDS or DASH diet score experienced lower risk of both all-cause (HR 0.77; 95% CI 0.66-0.90 and 0.81; 0.69-0.96, respectively, highest vs lowest quartile) and CVD (0.77; 0.59-1.00 and 0.81; 0.69-0.96, respectively) death risk; risk reduction associated with the Palaeolithic diet was limited to total and other cause death, whereas the Nordic diet did not alter risk of mortality. Increasing adherence to MD was associated with higher survival in each stratum of non-MD diets. Biomarkers of glucose metabolism accounted for 7% and 21.6% of the association between either MDS or DASH diet, respectively, with total mortality risk.

Conclusions: Both the traditional MD and DASH diet may reduce risk of all-cause mortality among Italians, as well as risk of dying from cardiovascular causes. The Palaeolithic diet did not appear to reduce cardiovascular risk, while the Nordic eating pattern was unlikely to be associated with any substantial health advantage.