Groundbreaking PCRM Study Shows the Dramatic Impact of a Low-Fat Vegan Diet
More than 20 million Americans have diabetes, a condition that greatly increases the risk of heart problems and other complications. A new study has shown that a low-fat vegan diet treats type 2 diabetes more effectively than a standard diabetes diet and may be more effective than single-agent therapy with oral diabetes drugs. The randomized controlled trial was conducted by doctors and dietitians with PCRM, George Washington University, and the University of Toronto, with funding from the National Institutes of Health and the Diabetes Action Research and Education Foundation.
The study involved 99 individuals in the greater Washington, D.C., area with type 2 diabetes. Half the group was randomly assigned to follow a low-fat vegan diet, with no limits on calories, carbohydrate, or portion sizes. The other study participants were asked to follow a diet based on the American Diabetes Association’s (ADA’s) guidelines, which involves calorie counting and portion control, but allows most foods, including meats and dairy products, in limited amounts. Participants in both groups followed the diet for 22 weeks and received dietary support in the form of cooking demonstrations, tips on following the diet they were on, and group meetings.
While participants in both groups improved, the vegan group experienced significantly greater reductions in A1c (a measure of blood sugar levels over a prolonged period), weight, body mass index, waist circumference, and LDL (“bad”) cholesterol.
Specifically, excluding the participants who changed or reduced their medication, A1c fell 1.23 points in the vegan group, compared with 0.38 points in the ADA group. Those in the vegan group dropped an average of 6.5 kg (14.3 pounds) each, while those on the ADA diet lost about 3.1 kg (6.8 pounds). Among those who did not change lipid-lowering medications, LDL cholesterol dropped 21.2 percent in the group following the vegan diet, and 10.7 percent in the ADA group.
“The diet appears remarkably effective, and all the side effects are good ones—especially weight loss and lower cholesterol,” said lead researcher Neal D. Barnard, M.D., PCRM president and adjunct associate professor of medicine at George Washington University. “I hope this study will rekindle interest in using diet changes first, rather than prescription drugs.”
Study authors and two participants in the vegan diet group held a news conference in Washington, D.C., in late July. Dr. Barnard, along with Joshua Cohen, M.D., associate professor of medicine at the George Washington University Medical Center, and David Jenkins, M.D., Ph.D., Sc.D., of the University of Toronto, explained to reporters the significance of the findings. News reports of the study appeared in newspapers in the U.S. and abroad.
Learn more at PCRM.org/Diabetes.