Should diabetics drink coffee? A survey reported in JAMA (July 6, 2005) showed that drinking coffee reduces risk for developing type II diabetes, but two other studies suggest that once you have diabetes, drinking coffee may be unwise.
Canadian researchers writing in Diabetes Care (March 2005) showed that caffeine significantly reduced insulin sensitivity. In the July 2005 issue of the same journal, scientists from Duke University Medical Center reported that drinking coffee could upset a diabetic’s ability to metabolize sugar.
Blood sugar levels are supposed to rise after you eat. To keep your blood sugar levels from rising too high, your pancreas releases insulin. The researchers found that taking caffeine causes blood sugar and insulin levels to rise even higher after meals. If your blood sugar rises too high, sugar sticks to cells. Once sugar is stuck on a cell membrane, it cannot be released and is converted to a poison called sorbitol which destroys that cell. High levels of insulin constrict arteries to cause heart attacks and act directly on the brain to make you hungry, on your liver to make more fat, and on the fat cells in your belly to pick up that fat. If these studies are confirmed, diabetics will be advised to restrict coffee as well as those foods that cause the highest rise in blood sugar after meals.