News & Research

A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes, by N.D. Barnard and colleagues. Diabetes Care 29:1777-1783, 2006

Why did the researchers do this particular study?

The researchers wanted to see whether following a low-fat vegan diet can help people control their blood glucose levels and lower the amount of fats and cholesterol in their blood.

A vegan diet doesn't contain any animal products (meat, dairy, or eggs).

Who was studied?

Ninety-nine people who had type 2 diabetes.

How was the study done?

Forty-nine people followed a low-fat vegan diet; 50 people followed a diet based on the nutrition recommendations of the American Diabetes Association. The people received a check-up after 22 weeks.

The low-fat vegan diet consisted of vegetables, fruits, grains, and legumes. About 10% of calories came from fat, 15% came from protein, and 75% came from carbohydrates. People on the vegan diet were asked to avoid animal products and any added fats, as well as to favor low-glycemic-index foods, such as beans and green vegetables.

What did the researchers find?

All of the people who stuck to their diets, regardless of whether they were on the vegan diet or the diet based on ADA nutrition recommendations, improved their blood glucose levels, lost weight, lowered their lipid levels (fats in the blood), and lowered their cholesterol levels (cholesterol is a waxy, fat-like substance that builds up in blood vessels). These improvements were greater in the people who were on the low-fat vegan diet.

What are the limitations of the study?

Both diets made the people who were on diabetes medication prone to hypoglycemia (or very low blood glucose levels). As a result, these patients had to adjust their medications, and this may have affected the interpretation of the results.

What are the implications of the study?

Eating right and exercising are the best ways for patients with type 2 diabetes to begin to treat their disease. This study shows that a low-fat vegan diet and a diet based on ADA nutrition recommendations can help people with type 2 diabetes control their blood glucose levels and lower their chances for heart and blood vessel problems. These improvements were greater with the low-fat vegan diet.

FOR MORE INFORMATION

Diabetes, Cholesterol and Heart Disease

Learn About the Glycemic Index

Making Healthy Food Choices

Weight Loss Matters Tip Sheet