High-Sugar Foods May Affect Eyesight
Carbs High on the Glycemic Index May Increase Age-Related Macular Degeneration
July 13, 2007 -- Eating lots of sugary, starchy foods may make eyes more
vulnerable to age-related macular degeneration (AMD), America's top cause of
That news appears in The American Journal of Clinical Nutrition.
AMD typically starts late in life. It affects the retina, located in the
center of the eye. AMD can cause vision loss.
Previous research shows that
diets rich in antioxidants might help prevent AMD.
The new study adds one more diet tip: Go for carbohydrates that don't make
your blood sugar spike quickly.
Doing so might help prevent AMD, note the researchers. They included
Chung-Jung Chiu, DDS, PhD, and Allen Taylor, PhD. They work in Boston at Tufts
University's Jean Mayer U.S. Department of Agriculture Human Nutrition Research
Center on Aging.
Nearly 4,100 U.S. adults aged 55-80 took part in the study. They completed
dietary surveys and had their eyes checked for AMD.
The dietary surveys listed 90 foods. Participants noted how often and how
much of those foods they typically ate.
The researchers paid close attention to the glycemic index -- a measure of
how much certain foods raise blood sugar.
Sugary items and refined grains (such as white flour, which has the bran
stripped out of it) are examples of foods that rank high on the glycemic
index. Whole grains, legumes, and vegetables rank lower on the glycemic
Glycemic Index and AMD
The researchers tracked AMD by eye, not participant, because some people may
have had AMD in one eye but not the other.
Most eyes showed no signs of AMD. But 602 eyes had advanced AMD.
People with the diets highest on the glycemic index were the most likely to
have advanced AMD in at least one eye.
Those findings held when the researchers considered participants' age,
gender, and other risk factors.
The study doesn't show exactly what caused AMD. It's not clear that
diet was solely responsible for any cases of AMD. Participants weren't followed
over time, and they weren't asked to change their diets for the study.
However, the researchers estimate that a fifth of the advanced AMD cases in
their study might have been prevented by eating foods low on the glycemic