Low-glycemic diet could help prevent AMD

Researchers from Tufts University discovered that lab mice fed on a low-glycic diet did not develop AMD features, unlike those placed on a high-glycic diet.{{quote-A:R-W:450-I:2-Q:“Mice on the high-glycic diet developed many AMD symptoms” -WHO:Professor Sheldon Rowan, Scientist in the Laboratory for Nutrition and Vision Research}}“We were genuinely surprised that the retinas from mice whose diets were switched from high to low-glycic index diets midway through the study were indistinguishable from those fed low-glycic index diet throughout the study,” lead author Professor Sheldon Rowan said.“We hadn’t anticipated that dietary change might repair the accumulated damage in the RPE so effectively. Our experimental results suggest that switching from a high-glycic diet to a low-glycic one is beneficial to eye health in people that are heading towards developing AMD.”The findings, published recently in the journal PNAS, helped identify potential biomarkers of AMD, which could be used to predict a person’s susceptibility to the disease.Researchers used 59 randomised aged mice divided into two groups. Nineteen were fed with a low-glycic diet, while 40 were assigned to the high-glycic diet group. Both diets differed only in the source of carbohydrates.Two starch types were used for the diets; amylopectin and amylase. The high-glycic starch was formulated with 100% amylopectin while the low-glycic starch was a combination of 70% amylopectin and 30% amylose. Then, after a period of six months, some of the high-glycic mice were switched to the low-glycic group and some were retained the high-glycic diet.Mice on the high-glycic diet developed many AMD symptoms and characteristics, including loss of cellular function at the back of the eye and damage to photoreceptors.Advanced glycation end products (AGE), which form when sugar metabolites react with proteins, were identified by researchers as potential biomarkers of AMD, along with C3-carnitice, oxidised fats and serotonin levels.“Clinical tests are already available to test for some of these potential biomarkers. A screening of C3-carnitine levels is a standard part of the newborn screening profile, so it would not be challenging to adapt the existing screening to evaluate levels in AMD. There are also efficient clinical measures for serotonin. AGEs, however, are still erging biomarkers, and have not been used on large-scale human studies yet. Even so, AGEs are among the most exciting potential AMD biomarkers, since we understand their damaging molecular effects very clearly,” Rowan added.