Plant-Based Dietary Patterns and the Incidence of Diabetes in the Boston Puerto Rican Health Study

Abstract

Objectives To examine the associations between the plant-based diet and risk of developing diabetes in participants of the Boston Puerto Rican Health Study. Methods Included were 691 Puerto Ricans aged 45–75 years who were free of diabetes at baseline. Dietary intake was assessed via a validated food frequency questionnaire. Three plant-based dietary indices were then calculated, including an overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and an unhealthful plant-based diet index (uPDI). Incident diabetes was defined as fasting plasma glucose 126 mg/dL [7.0 mmol/L], hemoglobin A1c 6.5% [48 mmol/mol] or use of any hypoglycemic agents during follow-up. Cox proportional hazards models were used to evaluate the associations between the plant-based dietary patterns and the incidence of diabetes, adjusting for potential confounders, such as age, sex, socioeconomic status, lifestyle factors, obesity, total energy intake, depression, and plasma concentrations of c-reactive protein and lipid profiles. Results During the 5-years of follow-up, we identified 139 incident diabetes cases. After adjustment for covariates, hPDI was inversely associated with the risk for developing diabetes (P-trend = 0.04). The adjusted hazard ratio (HR) for the highest vs lowest tertiles of hPDI was 0.56 (95% confidence interval: 0.32–0.96). In contrast, The PDI and uPDI dietary indices were not significantly associated with the risk of diabetes (P-trend > 0.2 for both). Conclusions The healthful plant-based dietary index was associated with a lower risk of diabetes. These findings suggest that the healthful plant-based dietary index may be beneficial for the prevention of the development of diabetes. Funding Sources This project was supported by the National Institute on Aging, the National Heart, Lung, and Blood Institue, and the National Center for Advancing Translational Sciences.