PARSIPPANY, NJ, July 11, 2002 - Previous studies have shown that certain nutrients may protect against the most common form of cataracts, nuclear cataracts. However, few studies have reported an effect of nutrition on reducing the risk of developing cortical or posterior subcapsular cataracts. A study published in the March issue of the American Journal of Clinical Nutrition, however, supports a role for the antioxidant vitamin C in reducing the risk for developing cortical cataracts in women under the age of 60 and for carotenoids in diminishing the risk of posterior subcapsular cataracts in women who have never smoked. Roche Vitamins provided a grant for this analysis.
Cataracts, which affect more than half of all Americans aged 65 and older, develop when lens proteins are damaged, resulting in opaque spots (lens opacities) that can severely obstruct vision and ultimately lead to blindness. Nuclear (central) and cortical (peripheral) are two types of age-related cataracts, which are named for their location in the eye. Posterior subcapsular cataracts (PSC), a third type that develops under the lens cap, are associated with trauma to the eye, diabetes or use of medications such as corticosteroids. Cortical and PSC cataracts are less common than nuclear cataracts, but are still serious and can cause blindness if untreated.
It has been theorized that among other factors, photooxidative damage contributes to the development of lens opacities and ultimately, cataracts. Antioxidant vitamins and carotenoids, nutrients that act like antioxidants, have been found to neutralize free radicals that cause oxidative damage.
This study was the second analysis from the Nurses Health Study (NHS) that measured the occurrence of cataracts in women. The study, led by Allen Taylor, PhD, director of the laboratory for Nutrition and Vision Research at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, found no associations between usual intakes of nutrients from food and/or supplements overall for either cortical or PSC lens opacities, but significant associations were seen in selected subgroups.
A 57% lower risk for cortical lens opacities was seen in women less than 60 years old with a vitamin C intake of <362 mg/day than an intake of <140 mg/day. Moreover, women who took vitamin C supplements for <10 years had a 60% lower risk than those who didn't take a vitamin C supplement. Also, the prevalence of PSC lens opacities was reduced in women who never smoked with higher intakes of carotenoids. The first analysis, published July 2001 in the Archives of Ophthalmology, found that individuals with the highest intake of the antioxidant vitamin C had significantly lower rates of the more common, nuclear cataracts.
"This research adds more weight to the accumulating evidence that antioxidant nutrients can be utilized to alter the development of these serious, but less studied, forms of cataracts," said Dr. Taylor.
Participants in the Nutrition and Vision Project, a cohort from the NHS, were non-diabetic women aged 53 to 73 years without previously diagnosed cataracts. Data on usual nutrient intake and dietary supplement use were collected over a period of 13 to 15 years.
Roche Vitamins Inc. is a leading bulk manufacturer of vitamins, carotenoids and essential fatty acids. Beginning with the commercial synthesis of vitamin C in the 1930s, Roche has been involved in the research, development, production and marketing of these nutrients. Roche Vitamins Inc. is the North American vitamins business affiliate of F. Hoffmann-LaRoche Ltd of Basel, Switzerland.
For further information, please contact Roche Vitamins Inc. at 45 Waterview Boulevard, Parsippany, New Jersey, 07054-1298. Phone: 1-800-526-0189, ext 8239. Fax: 973-257-8592. E-mail: RVIUSA.nutrients@ROCHE.COM. Website: www.nutraaccess.com.
1. Taylor A, Jacques P, Chylack LT, Hankinson SE, et al., Long-term intake of vitamins and carotenoids and odds of early related age-related cortical and posterior subcapsular lens opacities.¢®¡§ Am J Clin Nutr 2002;75:540-9.