Clear Vision Calls For Long-Term Investment in Vitamin CBy
New findings from a USDA study
of 247 women confirm that long-term use of vitamin C supplements
substantially reduces the risk of cataract--a clouding of the eye's
lens. There were 77 percent fewer early-stage cataracts among the
women who took the supplements daily for more than 10 years than among
those who didn't supplement.
Cataracts are thought to result from oxidation of lens proteins, and
vitamin C prevents oxidation, the researchers said. But women who took
the supplements for less than a decade had no detectable difference in
cataract prevalence, according to findings published in the October
issue of the American Journal of Clinical Nutrition.
The study was conducted by Paul F. Jacques, Allen Taylor and other
researchers at the Jean Mayer USDA
Human Nutrition Research Center
on Aging at Tufts, Boston, and colleagues with the Harvard
University Nurses Health Study. The Boston center is funded by USDA's
Agricultural Research Service.
The findings emphasize that cataracts are a chronic condition that
takes many years to develop and therefore requires a long-term
solution, the researchers concluded. They selected the participants
from the 21-year-old Nurses Health Study based on high and low vitamin
The findings corroborate a 1992 report that linked 10-plus years of
vitamin C supplements with far fewer cataract surgeries among nurses
in the larger Harvard study.
In the current study, the supplement users took at least 500
milligrams of vitamin C daily in addition to food and multivitamin
sources. Unfortunately, there were too few women in this study to
assess whether long-term vitamin C intake from foods or multivitamins
protects against cataracts. None of the women had been previously
diagnosed with the condition, and each had reported her food and
supplement intake several times before being examined for lens
Scientific contacts: Paul F. Jacques or Allen Taylor,
Jean Mayer USDA Human Nutrition
Research Center on Aging at Tufts University, Boston, Mass.
Jacques: phone (617) 556- 3237, email@example.com.
Taylor: phone (617) 556-3155,
Fax (617) 556-3344.