CINCINNATI—A new study by researchers at the University of Cincinnati (UC) finds that a low-carbohydrate, high-monounsaturated fat diet was just as beneficial for persons with type 2 diabetes as the traditional low-fat, high-carbohydrate diet.
“The most important aspect of this research is that there are alternatives to the conventional low-fat, high-carb diet,” says the study’s principal investigator, Bonnie Brehm, PhD.
Brehm, a registered dietitian and professor at UC’s College of Nursing, and her colleague David D'Alessio, MD, with UC’s College of Medicine, division of endocrinology and metabolism, prescribed one of two study diets to 124 overweight men and women, all with type 2 diabetes. Half of the group was randomly selected to follow a conventional low-fat, high-carb meal plan while the other half was placed on what is commonly known as the Mediterranean diet: foods typical of the Mediterranean region with an emphasis on vegetables, fruits, whole grains, legumes, nuts and olive oils.
Several small studies had previously suggested that Mediterranean diets, with a large proportion of their fat content made up of monounsaturated fats such as olive oil, had beneficial effects on blood glucose and lipid levels in patients with diabetes. However, these results had been lost in the rush by dietitians and clinicians to reduce patients’ fat intake, and Mediterranean diets had not been tested in larger, longer-term studies of persons with diabetes.
“The thinking has always been that high-fat diets were not healthy for anybody,” says Brehm, “but this shows that you can recommend a higher-fat diet, as long as it is healthy fat.”
According to the study, reported first in the Oct. 28 e-publication of Diabetes Care, both diets were found to be equally beneficial: Both groups had similar weight loss over one year (approximately 4 kilograms, or 9 pounds) and had comparable improvement in body fat, waist circumference, diastolic blood pressure, HDL cholesterol, A1C and fasting glucose and insulin.
”While a 4-kilogram weight loss is much less than what most patients want for cosmetic reasons, this is a clinically significant reduction,” D’Alessio says. “Weight loss of this magnitude can improve blood pressure as well as lipid and glucose values, and also can reduce the number of medications people need to take.”
The American Diabetes Association (ADA), which funded the UC study, reports that 23.6 million children and adults in the United States, or 8 percent of the population, have diabetes. More than 90 percent of these individuals have type 2 diabetes, a condition strongly linked to obesity. People with type 2 diabetes have abnormally low secretion of insulin, and are resistant to the action of insulin to promote glucose uptake into cells. The insulin resistance is at least partially related to obesity, and weight loss can restore patients’ insulin signaling.
Type 2 diabetes is a particularly important problem in the Cincinnati area where estimates are that approximately 10 percent of the population is affected. The current rise in the number of people developing diabetes has led local health advocacy groups to project that one in four Cincinnatians will have diabetes by 2020.