Do Low-Carb Diets Help Diabetes?
Small Study Shows Restricting Carbohydrates Reduces Need for Medications
March 15, 2006 -- Should people with type 2 diabetesdiabetes follow very low carbohydrate diets? The American Diabetes Association (ADA) says "no", but a small study from Sweden suggests such a diet may be one of the best ways to manage the disease and reduce the need for medication.
In the study, 16 obese patients with type 2 diabetes followed a calorie- and carbohydrate-restricted diet for 22 months. Most showed continuing improvements in blood sugar that were independent of weight lossweight loss; the average daily dosage of insulin among the 11 insulin-dependent patients was cut in half.
"Many people are essentially cured of their [type 2] diabetes by low-carbohydrate diets, but that message is not getting out," says low-carb proponent and biochemistry professor Richard Feinman, PhD, of the SUNY Downstate Medical Center in Brooklyn, N.Y.
While agreeing that carbohydrate restriction helps people with type 2 diabetes control their blood sugar, ADA spokesman Nathaniel G. Clark, MD, tells WebMD that the ADA does not recommend very low-carb diets because patients find them too restrictive.
"We want to promote a diet that people can live with long-term," says Clark, who is vice president of clinical affairs and youth strategies for the ADA. "People who go on very low carbohydrate diets generally aren't able to stick with them for long periods of time."
Low-Calorie vs. Low-Fat
In the Swedish study, obese patients with type 2 diabetes were asked to follow two different low-calorie diets for 22 months.
Sixteen patients were told to restrict carbohydrates to just 20% of their total calorie intake, with carbohydrate consumption limited to vegetables and salads. Bread, pasta, potatoes, rice, and breakfast cereals were not allowed.
Fifteen more patients were asked to follow a low-fat diet, which had the same number of calories -- 1,800 calories-a-day for men and 1,600 for women. Carbohydrates made up as much as 60% of daily calories. (Seven of the 15 patients in this group switched to the low-carbohydrate diet before the study ended.)
Researchers Jorgen Vesti Nielsen and Eva Joensson reported that more patients in the low-carbohydrate group than the low-fat group lost weight. But after 22 months, most patients had gained back some of the weight they had lost at six months.
Dependence on the oral diabetes drugs metformin and sulfonylureas was reduced in one-fifth of the patients in the original low-carbohydrate arm of the study at six months; two patients had stopped taking them. It is not clear if these patients still had reduced dependency on medication at 22 months.