The number one cause of irreversible blindness in adults is age-related macular degeneration (AMD), which seems to share several carbohydrate-related risk factors with diabetes-related diseases, including retinopathy and cardiovascular disease (CVD). In a new study published in the American Journal of Clinical Nutrition, researchers tested the theory that dietary glycemic index (GI), which has been associated with the risk of diabetes and CVD, may also increase the risk and severity of AMD in elderly populations. Over 4000 participants aged 55-80 years participated in the research and were assigned to groups according to several physical eye characteristics related to AMD. Compared with the eyes in those with the lowest GI diets, eyes in the high GI subjects had significantly higher risk of AMD progression and severity. There was a 49% increase in the risk of advanced AMD for persons who ate a diet higher than average in GI. Researchers noted that the results indicated that 20% of all AMD cases in the study would have been eliminated if the participants consumed diets with a GI below the average. The association between dietary GI and AMD suggests that reducing the dietary GI may provide one way to reduce the risk of AMD in adults.
American Journal of Clinical Nutrition, Vol. 86, No. 1, 180-188, July 2007