If you have diabetes, it may be wise to get the bulk of your fiber from low-glycemic foods high in fiber such as beans, lentils, nuts, pumpernickel bread, and oats. Although experts have long emphasized the importance of a diet rich in fiber and cereal grains for people with diabetes, recent research has shown that it’s the low-glycemic foods high in fiber that help the most with blood sugar control.
Low-glycemic foods are those that have the least impact on blood glucose levels. Only a small percentage of foods have been tested, but you can find these lists in books on the glycemic index or on the official website, www.glycemicindex.com. The very best way to find out the glycemic impact of a food on your own metabolism, however, is to eat the food and test your blood sugar.
The six-month study followed over 200 patients with type 2 diabetes, who were were randomly assigned to either a low-glycemic, high-fiber diet or a conventional, high-fiber diet. Participants were provided a checklist of recommended foods. The low-glycemic diet checklist included:
• pumpernickel, quinoa, and flaxseed breads;
• rye pitas
• bulgur and flax cereal
• large-flake oatmeal
• oat bran
• wheat bran
• legumes (beans, peas, lentils, and nuts)
• parboiled rice
Both diets were low in white flour and called for nonfat milk, yogurt, and cheese, and participants were instructed to eat five servings of vegetables and three servings of fruit each day. Both groups were strongly advised against nutrient-empty, high-carbohydrate foods such as pancakes, muffins, donuts, bagels, cookies, cakes, french fries, and potato chips.
Participants in the group eating conventional foods high in fiber saw a decrease of about 0.18% in their A1C levels. Members of the low-glycemic group, however, saw a drop averaging about 0.50%. In addition, HDL, or “good cholesterol” increased an average of 1.7 mg/dL in the low-glycemic group. HDL is associated with a lowered risk of heart disease.
Jenkins, David A., Cyril W. C. Kendall, Gail KcKeown-Eyssen et. al. 2008. Effect of a Low Glycemic Index or a High Cereal Fiber Diet on Type 2 Diabetes: A Randomized Trial. JAMA 300(23): 2742–2753.
Harvard Health Publications. Glycemic index and glycemic load for 100+ foods. (Accessed 3/230/09.)
Reviewed by Susan Weiner, RD, MS, CDE, CDN 4/11