Plant-Based Diets Best for Diabetes Prevention and Treatment, New Review of Scientific Literature Confirms

WASHINGTON—Plant-based diets are best for diabetes prevention and treatment, according to a new review published in Advances in Nutrition. Researchers with the Physicians Committee for Responsible Medicine reviewed studies looking at the evidence for type 2 diabetes prevention and treatment with a plant-based diet, as well as research that seeks to explain the mechanisms that make this approach so effective.

The research shows eating patterns that emphasize fruits, vegetables, legumes, and whole grains and remove animal products improve risk factors for diabetes, including blood sugar, cholesterol, weight, blood pressure, and cardiovascular disease. Reduced fat intake and increased high-fiber carbohydrate intake improve diabetes and heart disease risk factors and reduce the need for medication for blood sugar control.

“Our review of decades of scientific literature confirms what I’ve seen in practice over and over: Plant-based diets are a powerful prescription for preventing and reversing type 2 diabetes,” says Caroline Trapp, DNP, ANP-BC, CDE, FAANP, DipACLM, a co-author of the study and director of diabetes education and care for the Physicians Committee.

The review looked at several studies that show a plant-based diet can reduce type 2 diabetes risk, while eating meat, including poultry, can increase the risk. The authors cite an analysis of Adventist Health Study-2 participants who did not have diabetes: Vegan and lacto-ovo vegetarians had a 77% and 54% reduction in risk of developing diabetes, respectively, compared to nonvegetarians. A Harvard study that looked at participants from the Health Professionals Follow-Up Study, the Nurses’ Health Study, and the Nurses’ Health Study II found that increasing meat by half a serving per day was associated with a 48% increase in diabetes risk over a four-year period.

Several studies, including a 2003 study by the Physicians Committee for Responsible Medicine, found that plant-based diets, particularly vegan diets, are also effective at treating type 2 diabetes. The Physicians Committee’s 22-week clinical trial compared a low-fat, vegan diet, which got 75% of its calories from carbohydrates, to a conventional portion-controlled diet that followed 2003 American Diabetes Association guidelines. Among participants who made no medication changes, the vegan group had a significantly greater reduction in HbA1c, a measurement of blood sugar control. 

Plant-based diets are also beneficial for complications of type 2 diabetes, including cardiovascular disease, chronic kidney disease, neuropathy, and diabetic retinopathy, according to research cited in the paper.

The review also highlights the benefits of a plant-based diet compared with other dietary approaches for treating type 2 diabetes, including very-low-calorie diets, metabolic surgery, Mediterranean and Dietary Approaches for Stopping Hypertension (DASH) diets, and a low-carbohydrate eating pattern, which has several safety concerns. Plant-based dietary patterns improve body weight, insulin sensitivity and the function of the cells of the pancreas that make insulin, getting at key underlying causes of hyperglycemia. 

The authors suggest clinicians recommend plant-based diets to those who have or are at risk for diabetes and communicate the acceptability, nutritional adequacy, and benefits to overall health of this eating pattern.