January 31, 2002
Antioxidants May Slow the Progression
of Age-Related Cataracts
Age-related cataracts (ARC) are the leading cause of acquired blindness in
the United States. A new study published in the latest issue of Ophthalmic
Epidemiology shows that antioxidant supplements may slow the progression of
ARC.(1) In the Roche European American Cataract Trial (REACT), a supplement
containing beta-carotene and vitamins E and C slowed the progression of
cataracts. According to the authors, REACT is the first prospective,
randomized, placebo-controlled intervention trial with antioxidant vitamin
Cataracts are the clouding of the lens in the eye, which leads to vision
problems that can ultimately result in blindness. In this study, the
progression of lens clouding was significantly reduced in the supplemented
group, compared to those in the placebo group.
Participants in the REACT study were given a supplement containing 750 mg of
vitamin C, 600 IU of vitamin E and 18 mg of beta-carotene. Current U.S.
intake levels average around 90 mg of vitamin C, 9 mg of vitamin E and less
than 2 mg of beta-carotene.
Two million cataract extractions are performed per year, making it the most
common surgical procedure in the United States. For the individuals
afflicted with cataracts, the disease can rob them of their independence,
making everyday activities like reading or driving difficult or even
impossible. Based on one analysis, it was estimated that a 10% reduction in
cataract progression could reduce the number of cataract surgeries by
The study's authors hypothesized that if subjects in the supplemented group
continued their vitamin use over a 21-year period, they could achieve this
10% reduction. While the REACT authors do not suggest that vitamin treatment
would reduce the need for cataract surgery by 50%, they note that long-term
use of antioxidant vitamins could have a "sizable impact on the burden of
providing cataract surgery for cataract-blind individuals."
REACT supports the findings from a number of earlier epidemiological studies
that examined the role vitamins C and E may play in reducing the risk of
cataracts. In 1999, researchers analyzed data from NHANES II (Second
National Health and Nutrition Examination Survey) and found that individuals
with higher plasma vitamin C concentration had a lower risk of cataracts. In
the Longitudinal Study of Cataract, individuals with higher plasma vitamin E
also had a lower risk of cataracts.
REACT is a three-year clinical trial with 297 adults from the United States
and England. Participants were outpatients from ophthalmology clinics and
had been already diagnosed with early ARC.
The Vitamin Nutrition Information Service (VNIS) was founded by Roche
Vitamins Inc. in 1979 as a source of accurate and credible vitamin
information for health professionals, educators and communicators. The VNIS
monitors and disseminates vitamin research, sponsors professional symposia
on current vitamin topics and generates materials to educate professionals
about the roles of vitamins in health.