Low-Glycaemia Diet Shows Greater Improvement in Glycaemia Control than High-Fibre Diet
One dietary strategy aimed at improving both diabetes control and cardiovascular risk factors is the use of low–glycaemic index diets, but there is disagreement over their effectiveness, according to background information in the article.
David J. A. Jenkins, M.D., of St. Michael’s Hospital and the
In the low–glycaemic index diet, the following foods were emphasized: beans, peas, lentils, nuts, pasta, rice boiled briefly and low–glycaemic index breads (including pumpernickel, rye pita, and quintal and flaxseed) and breakfast cereals (including large flake oatmeal and oat bran). In the high–cereal fibre 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 haemoglobin A1c (HbA1c; a substance of red blood cells tested to measure the blood glucose level) decreased by –0.50 percent absolute HbA1c units in the low–glycaemic index diet compared with –0.18 percent absolute HbA1c units in the high–cereal fibre diet. Significant treatment effects were observed for high-density lipoprotein cholesterol (HDL-C) and the low-density lipoprotein cholesterol (LDL-C): HDL-C ratio. HDL-C increased in the low–glycaemic index diet group by 1.7 mg/dL and decreased by –0.2 mg/dL in the high–cereal fibre diet group. The LDL-C:HDL-C ratio showed a greater reduction in the low–glycaemic index diet group compared with the high–cereal fibre diet group.
"Lowering the glycaemic index of the diet improved glycaemic control and risk factors for coronary heart disease (CHD). These data have important implications for the treatment of diabetes where the goal has been tight glycaemic control to avoid complications. The reduction in HbA1c was modest, but we think it has clinical relevance," the authors write. "Low–glycaemic index diets may be useful as part of the strategy to improve glycaemic control in patients with type 2 diabetes taking antihyperglycaemic medications."
"Pharmacological interventions to improve glycaemic control in type 2 diabetes have often failed to show a significant reduction in cardiovascular events. In view of the 2- to 4-fold increase in CHD risk in participants with type 2 diabetes, the ability of a low–glycaemic index diet to address both glycaemic control and CHD risk factors increases the clinical relevance of this approach for patients with type 2 diabetes, such as those in this study, who are overweight and also taking statins for CHD risk reduction."
Article: Effect of a Low–Glycaemic Index or a High–Cereal Fibre Diet on Type 2 Diabetes: A Randomized Trial
David J. A. Jenkins; Cyril W. C. Kendall; Gail McKeown-Eyssen; Robert G. Josse; Jay Silverberg; Gillian L. Booth; Edward Vidgen; Andrea R. Josse; Tri H. Nguyen; Sorcha Corrigan; Monica S. Banach; Sophie Ares; Sandy Mitchell; Azadeh Emam; Livia S. A. Augustin; Tina L. Parker; Lawrence A. Leiter
JAMA. 2008;300(23):2742-2753
News Website: newswise
