Dietary Antioxidants and Long-term Risk of Dementia

Background

The Rotterdam Study previously found that higher dietary intakes of vitamins E and C related to lower risk of dementia and Alzheimer disease (AD) over 6 years of follow-up.

Objective

To study consumption of major dietary antioxidants relative to long-term risk of dementia.

Design

Population-based prospective cohort study.

Setting

The Rotterdam Study in the Netherlands.

Participants

A total of 5395 participants, 55 years and older, who were free of dementia and provided dietary information at study baseline.

Main Outcome Measures

Incidence of dementia and AD, based on internationally accepted criteria, relative to dietary intake of vitamin E, vitamin C, beta carotene, and flavonoids.

Results

During a mean follow-up period of 9.6 years, dementia developed in 465 participants, of whom 365 were diagnosed as having AD. In multivariate models adjusted for age, education, apolipoprotein E ε4 genotype, total energy intake, alcohol intake, smoking habits, body mass index, and supplement use, higher intake of vitamin E at study baseline was associated with lower long-term risk of dementia (P = .02 for trend). Compared with participants in the lowest tertile of vitamin E intake, those in the highest tertile were 25% less likely to develop dementia (hazard ratio, 0.75; 95% confidence interval, 0.59-0.95 with adjustment for potential confounders). Dietary intake levels of vitamin C, beta carotene, and flavonoids were not associated with dementia risk after multivariate adjustment (P > .99 for trend for vitamin C and beta carotene andP = .60 for trend for flavonoids). Results were similar when risk for AD was specifically assessed.

Conclusion

Higher intake of foods rich in vitamin E may modestly reduce long-term risk of dementia and AD.