http://www.ars.usda.gov/is/pr/2005/050630.htm
High Carb Diet May Cloud Vision Over Time
By Rosalie Marion Bliss
June 30, 2005
Scientists funded by the Agricultural Research Service (ARS) in Boston,
Mass., have found that the higher the carbohydrate intake, the higher
the odds of developing a certain type of cataract among a group of
women aged 53 to 73 years. When damaged proteins gather within one or
both of the eye lenses, the resulting area that becomes cloudy, or
opaque, is called cataract.
Cataract is the leading cause of blindness worldwide, and about 20
million Americans older than 40 have it. The study was led by
Chung-Jung Chiu and Allen Taylor at the Jean Mayer USDA Human Nutrition
Research Center on Aging in Boston and is part of the Nutrition and
Vision Project, a substudy of the federally funded Nurses' Health
Study.
The women in the study whose average carbohydrate intake was between
200 and 268 grams per day were 2.5 times more likely to get cortical
cataracts than the women whose intake was between 101 and 185 grams per
day. The recommended dietary allowance for daily carbohydrate intake
for adults and children is 130 grams, which is based on how much
glucose the brain needs.
Cortical cataract is one of three distinguishable types of cataracts.
Carbohydrates are mainly sugars and starches that the body breaks down
into glucose, a simple sugar that feeds the body's cells. The
potentially harmful effect of high-carbohydrate diets on the lens could
be a result of increased exposure of normal lens proteins to glucose.
The scientists studied 417 women without a history of cataracts who had
participated in the Nurses' Health Study. The researchers conducted eye
exams and studied dietary data taken from questionnaires to assess the
relationship between volunteers' newly diagnosed cataracts and their
average carbohydrate intake over a 14-year period.
The degree to which these findings could be generalized to men and
other age groups is unknown. But the mechanisms underlying cataract
development have not been known to vary by sex or socioeconomic status.
The study was published in the June issue of the American Journal of
Clinical Nutrition. ARS is the U.S. Department of Agriculture's chief
scientific research agency.
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TC