The development of age-related macular degeneration (AMD) and cataracts are associated with a high dietary glycemic index (GI), according to two separate studies published in the American Journal of Clinical Nutrition. The glycemic index is a measure of how quickly individual foods will raise the body's blood sugar level. Foods with a high GI (i.e., simple carbs) are rapidly absorbed and result in marked fluctuations in blood sugar levels. The first study, in the April issue of the journal, looked at 1,036 eyes of 526 Boston-based women enrolled in the Nutrition and Vision program at Tufts University. None of the women had AMD prior to enrollment. Dietary data were based on information from an average of four food-frequency questionnaires collected over a 10-year period before AMD assessment. Results showed that dietary glycemic index was related to the development of early AMD. Total carb intake was not related. The second study, in the May issue, looked at dietary information obtained from a food-frequency questionnaire given to 3,377 subjects who were part of the age-related eye disease study (AREDS). Results showed that dietary glycemic index was linked with a higher incidence of all single and moderate nuclear opacities. The researchers surmise that foods containing higher GI may advance damage to the tissue of the lens by exposing this tissue to glucose for longer periods. |
