Slowly digested, high-fiber carbohydrate foods such as whole grains, lentils, pinto beans, and kidney beans, can help reduce levels of C-reactive protein (CRP), a marker for the inflammation associated with heart disease and other chronic illnesses, by about 22 percent in overweight or obese adults. This finding comes from a study at the Fred Hutchinson Cancer Research Center in Seattle. Investigators put 80 participants on back-to-back 28-day diets, the first featuring high glycemic load carbs that are low in fiber and highly processed (they contain white sugar and white flour such as sugar-sweetened beverages and many breakfast cereals). These foods cause blood sugar levels to rise quickly. The other diet featured low glycemic load carbs that don't cause blood sugar to spike. The diets were otherwise identical in calorie, carbohydrate, protein and fat content. In addition to the effect on CRP, the researchers reported that the low glycemic load diet led to a five percent increase in a protein called adiponectin, which plays a key role in protecting against several types of cancer as well as type-2 diabetes, nonalcoholic fatty liver disease and hardening of the arteries. The study was published online on Dec. 21, 2011 by the Journal of Nutrition.
My take? I’m not surprised by these findings. I have recommended use of the glycemic index as a starting guide to healthy carbohydrate consumption for some time. In general, all you have to do is avoid frequent consumption and large servings of foods that rank high on this scale. For comparison, the glycemic index ranks pure glucose at 100. Foods ranking over 60 are considered high glycemic index carbs; they include potatoes, refined white and wheat bread, raisins and other dried fruit, bananas, carrots and watermelon. Foods ranked "moderate" (between 45 and 60) include most types of pasta, bulgur, baked beans, yams, green peas, sweet potatoes, orange juice and blueberries. Low glycemic index foods (below 45) include beans, cruciferous vegetables, yogurt, grapefruit, apples and tomatoes.