Abstract

Previous studies have found that vegan or vegetarian diets are related to improved glycemic control and decrease the risk of type 2 diabetes mellitus (T2DM). This work aims to determine the efficacy and safety of a plant-based diet and the risk of T2DM. A systematic search was carried out over different medical databases to identify internal medicine studies, which studied the outcome of the vegetarian group versus the non-vegetarian group of patients. Using the meta-analysis process, with either fixed- or random-effect models, we conducted a meta-analysis on the overall incidence of T2DM as the primary outcome, and we also conducted a correlation study between age and body mass index (BMI), and the risk of T2DM in vegetarians. Five studies were identified involving 69,213 patients. The estimated pooled incidence of T2DM was 4.98% (95% confidence interval = 2.469-8.32). Using the fixed-effect model, the meta-analysis process revealed ahighly significant decrease in T2DM incidence in the vegetarian group (p = 0.04). We also found that age and BMI had a non-significant correlation with the risk of T2DM in vegetarians (p > 0.5), respectively. To conclude, adherence to a plant-based diet may lower the risk of insulin resistance, prediabetes, and T2DM. These findings strengthen the recent dietary recommendations to adopt a more plant-based diet.

Key words: Plant-based diet, type 2 DM