Media Release

New research suggests plant-based low carbohydrate diet may control weight, improve blood sugar levels and lower cholesterol

Toronto, June 8, 2009

A new study showing that individuals who ate a low-calorie, low-carbohydrate diet high in plant-based proteins (“eco-Atkins”) for four weeks lost weight and experienced improvements in blood cholesterol levels and other heart disease risk factors, according to the newest study published today in JAMA's Archives of Internal Medicine by Dr. David A. Jenkins, a doctor and scientist at St. Michael's Hospital. A high-carbohydrate, low-fat vegetarian diet also resulted in weight loss but without the additional cardiovascular benefits.

Low-carbohydrate diets with increased meat consumption have also been promoted for body weight reduction and the prevention and treatment of diabetes and coronary heart disease. These diets have been shown to be effective in inducing weight loss, reducing insulin resistance, lowering blood fats known as triglycerides and raising high-density lipoprotein cholesterol (HDL-C, or “good” cholesterol) levels, but have tended to increase low-density lipoprotein cholesterol (LDL-C, or “bad” cholesterol) levels.

“For those already at risk of coronary heart disease who wish to try a lower carbohydrate diet, eating a plant-based diet low in calories and low carbohydrates could be the answer. Our study shows an eco-Atkins diet can significantly reduce bad cholersterol levels and deliver optimal weight loss. Not only does this help people at risk of heart disease, eating a plant-based diet is environmentally sustainable,” said Dr. Jenkins.

Dr. Jenkins and colleagues tested the effects of a low-carbohydrate diet high in vegetable proteins from gluten, soy, nuts, fruits, vegetables, cereals and vegetable oils among overweight men and women with high LDL cholesterol levels. A total of 24 participants began the “Eco-Atkins” diet for four weeks, while an additional 23 consumed a diet that was high-carbohydrate, lacto-ovo vegetarian and based on low-fat dairy and whole grain products. Study food was provided to participants at 60 percent of their estimated calorie requirements.

Of the 47 participants who began the study, 44 (22 in each group) completed the four-week period. Weight loss was similar—about 4 kilograms or 8.8 pounds—in both groups. However, reductions in LDL-C levels and improvements in the ratios between total cholesterol and HDL-C were greater for the low-carbohydrate diet compared with the high-carbohydrate diet. The low-carbohydrate diet also appeared to produce beneficial changes in levels and ratios of apolipoproteins, proteins that carry fats in the blood. In addition, small but significantly greater reductions were seen in both systolic (top number) and diastolic (bottom number) blood pressure for the low-carbohydrate vs. the high-carbohydrate group.

About Dr. David Jenkins:

Dr. Jenkins researches how diet can help in the prevention and treatment of hyperlipidemia and diabetes. His team was the first to define and explore the concept of the glycemic index of foods and demonstrate the breadth of metabolic effects of viscous soluble fiber, including blood glucose and cholesterol lowering. His studies on combining cholesterol lowering food components have been recognized as creating an effective dietary alternative to drug therapy. Dr. Jenkins works with the food industry to develop consumer products with specific health attributes. Dr. Jenkins is a Professor of Medicine and Canada Research Chair at the University of Toronto and St. Michael's Hospital.

St. Michael’s Hospital is a large and vibrant teaching hospital in the heart of Toronto. The physicians and staff of St. Michael’s Hospital provide compassionate care to all who walk through its doors and outstanding medical education to future healthcare professionals in more than 20 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care and care of the homeless and vulnerable populations in the inner city are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing Knowledge Institute; research at St. Michael’s Hospital is recognized, respected and put into practice around the world. Founded in 1892 by the Sisters of St. Joseph, the Hospital is fully affiliated with the University of Toronto.

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