For people who have type 2 diabetes, a low-glycemic index diet is significantly better than a high-fiber diet for keeping blood glucose levels down, researchers report.
Glycemic index, or GI, refers to how rapidly a food causes blood sugar to rise. High-GI foods, like white bread and potatoes, tend to spur a quick surge in blood sugar, while low-GI foods, such as lentils, soybeans, yogurt and many high-fiber grains, produce a more gradual increase in blood sugar.
The current study in this week's Journal of the American Medical Association involved 210 individuals with type 2 diabetes treated with anti-diabetes medications who were randomly allocated to go on to either a low-GI diet or a high-fiber diet for 6 months. The main outcome measured was the change in A1C in the blood, which reflects glucose levels over the long term.
A1C fell 0.50 percent on the low-GI diet compared with only 0.18 percent on the high-fiber diet, Dr. David J. A. Jenkins, from the University of Toronto, and co-researchers report.
Furthermore, levels of HDL ("good") cholesterol levels rose with the low-GI diet but they fell with the high-fiber diet.
"Low-glycemic index diets may be useful as part of the strategy to improve glycemic control in patients with type 2 diabetes taking (glucose-lowering) medications," the researchers conclude.
SOURCE: Journal of the American Medical Association, Dec. 17, 2008.
