Impact of antioxidants, zinc, and copper on cognition in the elderly: a randomized, controlled trial.
Participants in the Age-Related Eye Disease Study were randomly assigned to receive daily antioxidants (vitamin C, 500 mg; vitamin E, 400 IU; beta carotene, 15 mg), zinc and copper (zinc, 80 mg; cupric oxide, 2 mg), antioxidants plus zinc and copper, or placebo. A cognitive battery was administered to 2,166 elderly persons after a median of 6.9 years of treatment. Treatment groups did not differ on any of the six cognitive tests (p > 0.05 for all). These results do not support a beneficial or harmful effect of antioxidants or zinc and copper on cognition in older adults.