Eating for Healthy Eyes
Why complex carbs like whole grains are the clear choice for preserving vision, especially when it comes to age-related macular degeneration
Sheldon Rowan, a scientist in the Laboratory for Nutrition and Vision Research at the Human Nutrition Research Center on Aging at Tufts, said there are plenty of indications that the types of carbohydrates we eat play a role in the development of AMD. People who eat lots of simple carbohydrates, like those in white bread and sweetened beverages, are more likely to get the disease.
This could be because simple carbs break down rapidly during digestion, creating a spike in blood sugar that can lead to widespread inflammation, a condition linked to AMD. Complex carbohydrates found in whole grains, however, break down more slowly, resulting in lower blood glucose. If that blood glucose stays low over a long period of time, Rowan said, it can lower incidence of AMD.
To understand why, Rowan tested the two diets on laboratory mice. Over the course of a year, he fed one group of mice “high-glycemic” foods—ones with lots of simple starches. A second group got a “low-glycemic” diet, rich in complex carbs, but otherwise identical in calories and nutrients. In a third group, Rowan switched the mice’s diet from high- to low-glycemic foods halfway through the study.
Sure enough, mice with the low-glycemic diet did not develop AMD, while mice fed the high-glycemic diet almost all came down with the disease, a result in keeping with previous research. In the mice that switched diets, though, Rowan saw something completely unexpected. Not only did they avoid AMD, but the existing damage to their retinas was reversed….
Source: Tufts Now