Plasma levels of antioxidants are not associated with Alzheimer's disease or cognitive decline - A population-based study

Antioxidants prevent oxidative stress that possibly causes neuronal loss in Alzheimer's disease ( AD). We examined whether high plasma levels of the antioxidant vitamins A and E were associated with lower prevalence of AD or cognitive decline ( CD). We performed a cross-sectional study within the Rotterdam Study. In an univariate model, higher levels of vitamins A and E were significantly associated with lower prevalence of AD. However, when additional adjustments were made for important confounders, such as age, gender and total cholesterol, the relation substantially weakened - odds ratios per standard deviation increase were 0.87 (95% CI 0.64 - 1.19) for vitamin A and 0.94 ( 95% CI 0.60 - 1.48) for vitamin E. Antioxidants were not related to CD in nondemented subjects. Our findings suggest no association between plasma levels of vitamin A and E and AD or CD. Copyright (C) 2005 S. Karger AG, Basel.