By Joseph E. Scherger, MD, MPH

Core Faculty, Eisenhower Health Family Medicine Residency Program, Eisenhower Health Center, La Quinta, CA; Clinical Professor, Keck School of Medicine, University of Southern California, Los Angeles

Dr. Scherger reports no financial relationships relevant to this field of study.

SYNOPSIS: A large meta-analysis of high-quality observational studies shows that adherence to a plant-based diet is inversely related with developing type 2 diabetes.

SOURCE: Qian F, Lie G, Hu FB, et al. Association between plant-based dietary patterns and risk of type 2 diabetes: A systematic review and meta-analysis. JAMA Intern Med 2019; Jul 22. doi: 10.1001/jamainternmed.2019.2195. [Epub ahead of print].

A group at the Harvard T.H. Chan School of Public Health reviewed several observational studies that met stringent epidemiological guidelines regarding associations between nutrition and type 2 diabetes. Qian et al used an assessment tool from the National Institutes of Health to assess the quality of the studies. Nine studies that included 307,099 participants (23,544 cases of type 2 diabetes) were used in this analysis. All data showed an inverse relationship between a plant-based diet and developing type 2 diabetes. A plants-only diet was not required to prevent diabetes.


The “elephant in the room” with respect to the growing epidemic of insulin resistance and type 2 diabetes is the consumption of sugar and refined carbohydrates.1,2 Proponents of a whole food, plant-based diet like to point out the association of meat with the development of type 2 diabetes.3,4 There is a biological basis for their argument, but they tend to ignore the preeminent role of sugar and refined carbohydrates in the development of type 2 diabetes. The truth is that sugar and other carbohydrates come from plants, not animal sources. The quality of the plants ingested is vital to this argument. People who eat spinach, broccoli, and kale tend to eat much healthier than those who eat burgers.

The importance of this study and other investigations of connections between nutrition and type 2 diabetes is that this most expensive of chronic illnesses is preventable. There is a genetic risk that must be considered, but overweight, obesity, insulin resistance, metabolic syndrome, and type 2 diabetes are a continuum of epigenetic problems. Helping patients eat healthy goes a long way in preserving and restoring health and the prevention and reversal of chronic disease.


  1. Fung J. The Diabetes Code: Prevent and Reverse Type 2 Diabetes Naturally. Vancouver, BC: Greystone Books; 2018.
  2. Ludwig DS, Ebbeling CB. The carbohydrate-insulin model of obesity: Beyond “calories in, calories out.” JAMA Int Med 2018;178:1098-1103.
  3. Ornish D, Ornish A. Undo It!: How Simple Lifestyle Changes Can Reverse Most Chronic Diseases. New York: Ballantine Books (Penguin Random House); 2019.
  4. Greger M, Stone G. How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease. New York: Flatiron Books; 2015.