Adherence to a Mediterranean-style eating pattern and risk of diabetes in a U.S. prospective cohort study

According to the authors of a study published in the journal Nutrition and Diabetes, a Mediterranean-style eating pattern is consistently associated with a decreased diabetes risk in Mediterranean and European populations. However, results in U.S. populations are inconsistent. Their study therefore assessed whether a Mediterranean-style eating pattern would be associated with diabetes risk in a large, nationally representative U.S. cohort of black and white men and women. It also explored the consistency of associations within racial and BMI subgroups
Nearly 12,000 participants from the Atherosclerosis Risk in Communities study prospective cohort without diabetes, cardiovascular disease, or cancer at baseline (visit 1, 1987–1989) were included (mean age 54 years, 56% female, 75% white). Alternate Mediterranean Diet scores (aMed) were calculated using the mean dietary intake self-reported at visit 1 and visit 3 (1993–1995) or visit 1 only for participants censored before visit 3. Participants were followed from visit 1 through 31 December 2016 for incident diabetes. The associations of aMed with incident diabetes were characterised, adjusted for energy intake, age, sex, race and study center, and education for all participants then stratified by race and body mass index (BMI).
Over a median follow-up of 22 years, there were 4,024 incident cases of diabetes. Higher aMed scores were associated with lower diabetes risk [0.83 (0.73–0.94) for the top quintile score versus the lowest quintile score and 0.96 (0.95–0.98) for 1-point higher on the aMed score]. Associations were stronger for black vs white participants (interaction p < 0.001) and weaker for obese vs normal BMI.
The authors conclude that an eating pattern high in fruits, vegetables, whole grains, legumes, nuts, and fish, and moderate in alcohol, similar to the Mediterranean-style eating pattern assessed in this analysis and recommended by the 2015–2020 Dietary Guidelines for Americans, was associated with an overall lower risk of diabetes in a community-based U.S. population. This association was particularly strong for black and normal weight individuals but was absent for individuals who were overweight or obese. Increased awareness and promotion of healthy eating patterns for diabetes prevention in predominantly black communities may reduce disease burden. Future research is needed to assess if a calorically restrictive Mediterranean-style eating pattern, resulting in clinically meaningful weight loss, can reduce future diabetes risk in individuals who are overweight or obese.
Source: O’Connor, Lauren & Hu, Emily & Steffen, Lyn & Selvin, Elizabeth & Rebholz, Casey. (2020). Adherence to a Mediterranean-style eating pattern and risk of diabetes in a U.S. prospective cohort study. Nutrition & Diabetes. 10. 8