Increased consumption of nuts, especially tree nuts, is associated with lower incidence of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes, according to study results published in Circulation Research.
In this prospective analysis, investigators included men (n = 4211) and women (n = 12,006) with diabetes at baseline or diagnosed during follow-up in 2 prospective cohort studies (the Nurses’ Health Study and Health Professionals Follow-Up Study). Using validated semiquantitative food frequency questionnaires with approximately 131 food items administered every 2 to 4 years, participants were asked how often, on average, they had consumed nuts (serving size, 28 g [1 ounce]) during the preceding year for questionnaires in 1980 and 1984; subsequent to that, the question was divided into 2 categories: peanuts and tree nuts. The primary outcome measured mortality or CVD incidence, categorized as incident nonfatal myocardial infarction, coronary artery bypass graft surgery, and fatal and nonfatal stroke.
A total of 3336 incident CVD cases (2567 coronary heart disease cases and 789 stroke cases) and 5682 deaths (1663 CVD deaths and 1297 cancer deaths) were identified during 223,682 and 254,923 person-years of follow-up. Higher consumption of nuts was significantly associated with a lower risk for total CVD, coronary heart disease, CVD mortality, and all-cause mortality. Participants who consumed ≥5 servings of nuts/week had significantly lower rates of total CVD compared with participants who consumed <1 serving of nuts/month (hazard ratio, 0.83; 95% CI, 0.71-0.98; P =.01). No significant interactions were detected between nut consumption and stratifying variables (age, hypertension or hypercholesterolemia, and body mass index at diabetes diagnosis; sex/cohort; diabetes duration; smoking status; alcohol consumption; physical activity; or nut consumption before diabetes diagnosis).
The key limitation of this study was its observational design, meaning causality cannot be proven. Generalizability is also limited given the homogeneity in the study’s population.
The findings from this study confirm similar findings from clinical trials and suggest that nut consumption may improve glycemic control, blood pressure, lipid metabolism, inflammation, and endothelial dysfunction, and therefore has a role in preventing morbidity and mortality in patients with type 2 diabetes.
Liu G, Guasch-Ferré M, Hu Y, et al. Nut consumption in relation to cardiovascular disease incidence and mortality among patients with diabetes mellitus [published online February 19, 2019]. Circ Res. doi:10.1161/CIRCRESAHA.118.314316