Does a Mediterranean diet reduce the mortality risk associated with diabetes: Evidence from the Melbourne Collaborative Cohort Study

Background and aimsDiabetes is a risk factor for cardiovascular disease (CVD), yet southern European migrants to Australia with high rates of type 2 diabetes have relatively low CVD mortality. Our aim was to determine whether a Mediterranean style diet could reduce mortality in people with diabetes.Methods and resultsParticipants included 16,610 males and 23,860 females from the Melbourne Collaborative Cohort Study; 25% were born in Greece or Italy, and 2150 had previously been diagnosed with diabetes or had elevated blood glucose at baseline (1990–94). Data on demographic, behavioral and physical risk factors were also collected. A personal Mediterranean Diet Score (MDS) was calculated using data from a validated 121-item food frequency questionnaire. Total and CVD mortality data were available up to 2003.Diabetes (new and known) at baseline, was associated with total mortality (men HR 1.43, 95%CI 1.26–1.62; women HR 1.86 95%CI 1.58–2.18), and CVD mortality (men HR 1.53, 95%CI 1.21–1.94; women HR 2.10 95%CI 1.48–2.97) in multivariate models. There was no evidence that glucose tolerance modified the associations between MDS and total or CVD mortality (p interaction all > 0.16). The HRs for total mortality per unit of MDS were 0.96 (95% CI 0.93–0.99) in men and 0.94 (95% CI 0.92–0.97) in women. The HRs for CVD mortality per unit of MDS were 0.94 (95% CI 0.89–0.99) in men and 0.94 (95% CI 0.87–1.01) in women.ConclusionOur results add to the evidence supporting the benefit of a Mediterranean style diet for people with type 2 diabetes.