Tufts Study Finds Antioxidant Vitamin C
May Reduce Risk of Cataracts By 77 Percent in Women
WASHINGTON, Oct. 20 /PRNewswire/ — A Tufts University study has found that Vitamin C, an ntioxidant vitamin, may reduce the risk of cataracts in women by as much as 77 percent.
“These data, together with results from experimental studies and previous epidemiologic findings for cataract extraction, suggest that long-term consumption of high amounts of Vitamin C (in the present case primarily through dietary supplements) may substantially reduce the development of age-related lens opacities,” said Paul F. Jacques, scientist and epidemiologist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston.
Cataracts, found in nearly half of adults aged 65 and older, are created in the eye when proteins clump together and cloud the lens of the eye. They can cause blurred vision and poor night vision. Doctors and researchers have suggested that cigarette smoke and exposure to sunlight may accelerate the formation of cataracts.
The Tufts study, “Long-Term Vitamin C Supplement Use and Prevalence of Early Age-Related Lens Opacities,” evaluated 247 women, aged 56 to 71. It found that women who had taken Vitamin C for long periods of time showed fewer signs of cataracts.
“Use of Vitamin C supplements for 10 years or more was associated with a 77 percent lower prevalence of early lens opacities at any lens site and an 83 percent lower prevalence of moderate lens opacities at any lens site comparedwith women who did not use Vitamin C supplements,” the study said.
The study further suggested that Vitamin C reduces the risk of cataracts because it acts as an antioxidant. Antioxidants are compounds that protect the body from the formation of oxygen free-radicals — unstable oxygen molecules that can line the interior of blood vessels, thus restricting blood flow. The formation of free radicals can lead to an array of diseases. Vitamin C in particular may also protect the eye against damage from sunlight.
Vitamin C can be found in most fruits and vegetables, especially corn, blueberries, kale, spinach, oranges and beets, all of which have high concentration of antioxidants. However, many adults, including the elderly, do not get enough Vitamin C in their diet. Many doctors recommend daily supplements of 250-500 milligrams of Vitamin C for the best health benefits. Another antioxidant, Vitamin E, also has been the subject of recent health studies. Studies by research teams, published in scientific journals, have found that Vitamin E may help prevent heart disease, many forms of cancer, kidney disease, diabetes and osteoporosis, can fight Alzheimer’s disease, and strengthens immune systems in the elderly.
The Tufts study on Vitamin C showed the best results for women who had taken supplements of 400-800 milligrams daily. The study also recommended more research for further determination of the short-term and long-term effects of Vitamin C on cataracts.
(Foods for the Future provides factual information to the media concerning food products, health and nutrition. It is a project of the T. Dean Reed Company and is supported by U.S. agribusiness.)
SOURCE: Foods for the Future
Long-term vitamin C supplement use and prevalence of early age-related lens opacities
Am J Clin Nutr, 1997 Oct, 66:4, 911-6
We designed the present study to examine the cross-sectional relation between age-related lens opacities and vitamin C supplement use over a 10-12-y period before assessment of lens status in women without diagnosed cataract or diabetes. This design avoids biased measurement of nutrient intake that results when knowledge of lens opacities influences nutrition-related behavior or its reporting. The participants were 247 Boston-area women aged 56-71 y selected from the Nurses’ Health Study cohort with oversampling of women with high or low vitamin C intakes. Lens opacities were graded with the Lens Opacification Classification System II. Use of vitamin C supplements for > or = 10 y (n = 26) was associated with a 77% lower prevalence of early lens opacities (odds ratio: 0.23; 95% CI: 0.09, 0.60) at any lens site and a 83% lower prevalence of moderate lens opacities (odds ratio: 0.17; 95% CI: 0.03, 0.85) at any lens site compared with women who did not use vitamin C supplements (n = 141) after adjustment for age and other potentially confounding variables. Women who consumed vitamin C supplements for < 10 y showed no evidence of a reduced prevalence of early opacities. These data, together with data from earlier experimental and epidemiologic studies, suggest that long-term consumption of vitamin C supplements may substantially reduce the development of age-related lens opacities. (Emphasis mine, Rusty)