Mediterranean diet, cardiovascular health and longevity: Strategies to improve the assessment and interpretation of this dietary pattern in nutritional epidemiology

Introduction - Adherence to the Mediterranean diet, could reduce the risk of mortality and CVD across the life course. However, its epidemiological instrumentation needs to be
contextualized and adapted to local cultures. Moreover, there is evidence that typical dairy products should be disaggregated in the MDS due to divergent health properties.

Methods - The Västerbotten Intervention Program (VIP), the Northern Sweden MONICA, the H70 elderly study, the Copenhagen MONICA study, and the IDEFICS EU children study were included. A refined version of the Mediterranean Diet Score (MDS) was calculated from diet histories (H70), FFQs (VIP), and food records (MONICA-Copenhagen) by including foods that better describe the context of a genuine Mediterranean diet (e.g., wholegrain instead of total cereals) and ingredients from mixed dishes. Cox models, adjusted for potential confounders, were used to compare the original and refined MDS and their associations with mortality, CVD incidence, and mortality. Adjusted Cox models were also used to test the association between dairy intakes and the risk of mortality in the VIP and H70 cohorts. Adherence among children was assessed using both FFQ and recall data, and its association with BMI, waist circumference, WtHR, and % fat mass was assessed crosssectionally and longitudinally.

Results – The refined MDS, but not the original score, inversely predicted the risk of allcause mortality in the MONICA-Copenhagen (HR = 0.93) and VIP (HR = 0.95) studies, as well as with CVD incidence and CVD mortality in all cohort studies. Stroke incidence and stroke mortality were not associated with both scores. Milk intakes directly predicted all-cause mortality (HR = 1.02, 95% CI: 1.00, 1.05) whereas cheese intakes showed an inverse association with all-cause mortality (HR = 0.94, 95% CI: 0.91, 0.97). Fermented milk intakes showed a borderline significant inverse association with all-cause mortality. The MDS was inversely associated with the risk of overweight and obesity in children with low prevalence of high-adherent children in all countries (< 30%) except Sweden.

Discussion and conclusions - The adoption of a Mediterranean-like diet is protective for CVD across the lifespan, and adherence should be increased among children. The sensitivity
of assessments evaluating adherence to this pattern can be increased. The results on dairy product intakes suggest differences between milk and cheese, but they should be
interpreted cautiously.