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Research: CHRISTEN and COLLEAGUES,
Listed in Issue 165
Abstract
CHRISTEN and COLLEAGUES, Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. wchristen@rics.bwh.harvard.edu researched the effects of vitamin E supplementation upon age-related cataract in women.
Background
To investigate whether vitamin E supplementation decreases the risk of age-related cataract in women.
Methodology
Randomized, double-masked, placebo-controlled trial. Thirty-nine thousand eight hundred seventy-six apparently healthy female health professionals aged 45 years or older. Participants were assigned randomly to receive either 600 IU natural-source vitamin E on alternate days or placebo and were followed up for presence of cataract for an average of 9.7 years. Main Outcome Measure: Age-related cataract defined as an incident, age-related lens opacity, responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report and confirmed by medical record review.
Results
There was no significant difference between the vitamin E and placebo groups in the incidence of cataract (1159 vs. 1217 cases; relative risk [RR], 0.96; 95% confidence interval [CI], 0.88-1.04). In subgroup analyses of subtypes, there were no significant effects of vitamin E on the incidence of nuclear (1056 vs. 1127 cases; RR, 0.94; 95% CI, 0.87-1.02), cortical (426 vs. 461 cases; RR, 0.93; 95% CI, 0.81-1.06), or posterior subcapsular cataract (357 vs. 359 cases; RR, 1.00; 95% CI, 0.86-1.16). Results were similar for extraction of cataract and subtypes. There was no modification of the lack of effect of vitamin E on cataract by baseline categories of age, cigarette smoking, multivitamin use, or several other possible risk factors for cataract.
Conclusion
These data from a large trial of apparently healthy female health professionals with 9.7 years of treatment and follow-up indicate that 600 IU natural-source vitamin E taken every other day provides no benefit for age-related cataract or subtypes.
References
Christen WG, Glynn RJ, Chew EY and Buring JE. Vitamin E and age-related cataract in a randomized trial of women. Ophthalmology. 115(5): 822-829.e1. May 2008.