Washington, October 8 : The progression of age-related macular degeneration (AMD) can be slowed by eating fewer refined carbohydrates, suggest researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.

“Dietary changes may be the most practical and cost-effective prevention method to combat progression of AMD,” says Dr. Allen Taylor, director of the Laboratory for Nutrition and Vision Research at the USDA HNRCA.

“It is surprising there is so little attention focused on the relationship between AMD and carbohydrates,” he added.

Statistics from the Eye Diseases Prevalence Research Group show that AMD results in partial or total blindness in seven to 15 per cent of the elderly.

Published in the American Journal of Clinical Nutrition, the new study is a follow up of a recent analysis by Taylor and his colleagues wherein it was found that men and women over 55 years of age, who consumed diets with higher-than-average dietary gyfcemic index foods, had an increased risk of early and later stages of AMD.

Dietary glycemic index is a scale used to determine how quickly carbohydrates are broken down into blood sugar, or glucose.

During the study, the questionnaires completed by 4,757 non-diabetic men and women participating in the nationwide Age-Releated Eye Disease Study (AREDS) were analysed. The researchers examined the participants’ carbohydrate intake over a one-year period, and used the data to calculate the participants’ dietary glycemic index.

“Our data showed those people in the high-glycemic-index group were at greater risk of AMD progression, especially those already in the late stages,” says first author Dr. Chung-Jung Chiu, scientist in the Laboratory for Nutrition and Vision Research at the USDA HNRCA and assistant professor at Tufts University School of Medicine.

“Participants who consumed the most refined carbohydrates were 17 per cent more likely to develop blinding AMD than the group that consumed the least,” he added.

The authors of the study have also warned that the condition may spur a public health crisis in the US by 2020. They believe that the cases of AMD-related vision loss will have doubled to three million by that time.

“No one has been able to identify an effective noninvasive intervention that will slow the progression of AMD” says Taylor, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and Tufts University School of Medicine.

“We feel we have identified a risk factor that could postpone the debilitating loss of vision with very little economic or personal hardship. Based on our data, limiting refined carbohydrate intake, such as by limiting sweetened drinks or exchanging white bread for whole wheat, in at-risk elderly could reduce the number of advanced AMD cases by 8 percent in five years. This can equate to saving the sight of approximately 100,000 people,” he added.

The study’s authors note that their findings warrant randomised controlled clinical trials. (ANI)