In JAMA two prospective studies were published on the risk of AD associated with dietary intake of antioxidants. In the Rotterdam Study, a population-based study of individuals ages 55 years or older at baseline, investigators found that high intake of vitamin C and vitamin E from food was associated with lower risk of incident AD after a mean follow-up of six years, although statistical significance of the association was borderline. The Chicago Health and Aging Project study of individuals ages 65 years or older found that high intake of vitamin E from food was associated with reduced risk of AD after a mean follow-up of 3.9 years but only among individuals without the apoliproprotein E4 allele. Intake of vitamin E, vitamin C, and beta carotene from supplements, however, was not significantly associated with risk of AD. An editorial in the same issue of JAMA discussed methodological issues that must be considered in observational studies evaluating whether antioxidant vitamin intake reduces the risk of AD.
Reference: Psychiatric Times, Oct. 2005