The study led by researchers from St. Michael's Hospital and the University of Toronto have found that a diet high in low-glycemic foods improved both diabetes control and cardiovascular risk factors.
The study was conducted over 210 patients with type 2 diabetes, who were randomly assigned to receive 1 of the 2 diet treatments for 6 months.
In the low-glycemic index diet, the following foods were emphasized: beans, peas, lentils, nuts, pasta, rice boiled briefly and low-glycemic index breads (including pumpernickel, rye pita, and quinoa and flaxseed) and breakfast cereals (including large flake oatmeal and oat bran).
In the high-cereal fiber diet, participants were advised to take the "brown" option (whole grain breads; whole grain breakfast cereals; brown rice; potatoes with skins; and whole wheat bread, crackers, and breakfast cereals). Three servings of fruit and five servings of vegetables were encouraged on both treatments.
The researchers found that hemoglobin A1c tested to measure the blood glucose level significantly decreased by in the low-glycemic index diet compared with high-cereal fiber diet.
Those in the low-glycemic group also saw an increase in their high-density lipoprotein (HDL or "good") cholesterol of 1.7 mg/dL, compared to an HDL decrease of 0.2 mg/dL in the high-cereal-fiber group.
"Lowering the glycemic index of the diet improved glycemic control and risk factors for coronary heart disease (CHD)," said the authors.
"Low-glycemic index diets may be useful as part of the strategy to improve glycemic control in patients with type 2 diabetes taking antihyperglycemic medications," they added.