New Findings on Link Between Diet and Vision
Loss By Rosalie
Marion Bliss April 27, 2006
Scientists funded by the Agricultural Research Service (ARS) reported this month that consuming a
"high glycemic-index" diet over a long period of time is associated with a
higher risk of developing the early stages of a major eye disease--age-related
macular degeneration, or AMD.
The study was led by Chung-Jung Chiu and
Taylor at the
Mayer USDA Human Nutrition Research Center on Aging in Boston, Mass., and
is part of the Nutrition and Vision Project, a substudy of the federally funded
Nurses' Health Study.
A high glycemic-index diet is a diet high in the type of carbohydrates
that are quickly digested and absorbed, resulting in a rapid rise in blood
glucose levels. The macula is a yellow pigmented spot, one-eighth-inch wide, in
the center of the retina toward the back of the eye. AMD is one of the leading
causes of irreversible vision loss among those aged 40 or older in the United
Study participants were 526 women aged 53 to 73 years who did not have
a history of age-related maculopathy, the early form of AMD. The scientists
assessed the participants for macular disease and classified the results. They
then compared the results with long-term dietary information that had been
collected using questionnaires over a 10-year period prior to the macular
When ranked into three groups from highest to lowest in terms of
dietary glycemic index, the participants who were ranked highest were well over
two times more likely to have macular pigment abnormalities as those ranked
lowest. An abnormal level of macular pigment is an early indicator of macular
degeneration. The macula is responsible for the maximum ability to receive
light and distinguish images.
Although the data do not establish a causal relationship, they do
indicate a new direction for further studies that may help prevent or delay the
onset of macular disease.
The study was published in the April issue of the
American Journal of Clinical Nutrition. (View the citation for the article.)
ARS is the U.S.
Department of Agriculture's chief scientific research agency.