Women who stick to a plant-based portfolio diet lowered their risk of developing type 2 diabetes, according to a study published in ‘Diabetes Care’. The analysis included 145,299 postmenopausal women free of diabetes at baseline in the women's health initiative (WHI) clinical trials and observational study from 1993 to 2021. Adherence to the diet was assessed with a score based on six components (high in plant protein [soy and pulses], nuts, viscous fiber, plant sterols, and monounsaturated fat and low in saturated fat and cholesterol) determined from a validated food-frequency questionnaire. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs of the association of the portfolio diet, alongside the dietary approaches to stop hypertension (DASH) and Mediterranean diets, with incident type 2 diabetes, with adjustment for potential confounders.

Over a mean follow-up of 16.0 years, 13,943 cases of incident type 2 diabetes were identified. In comparisons of the highest with the lowest quintiles of adherence, the HRs for risk of incident type 2 diabetes were 0.77 (95% CI 0.72, 0.82) for the Portfolio Diet, 0.69 (0.64, 0.73) for the DASH diet, and 0.78 (0.74, 0.83) for the Mediterranean diet.

The researchers observed that greater adherence to the plant-predominant Portfolio, DASH, and Mediterranean diets was prospectively associated with a lower risk of type 2 diabetes in postmenopausal women.