Vitamin E and Dementia: An Update

From Medscape Neurology > Viewpoints

Laurie Barclay, MD
Posted: 07/28/2010
Dietary Antioxidants and Long-term Risk of Dementia

Devore EE, Grodstein F, van Rooij FJ, et al
Arch Neurol. 2010;67:819-825

Summary

Higher dietary consumption of vitamins E and C was previously associated with lower risk for dementia and Alzheimer disease (AD), according to 6-year findings from the Rotterdam Study.
The goal of the present population-based, prospective study was to further examine the relationship between intake of major dietary antioxidants and long-term risk of dementia in the same Dutch cohort.
The study sample consisted of 5395 participants at least 55 years old who had no dementia and who provided dietary information at study baseline.
Mean duration of follow-up was 9.6 years.

Of 465 participants in whom dementia developed during follow-up, 365 were diagnosed with AD.
Higher baseline intake of vitamin E was associated with lower long-term risk of dementia (P=.02 for trend), after adjustment for age, education, apolipoprotein E4 genotype, total energy intake, alcohol intake, smoking, body mass index, and use of supplements.
Dementia was 25% less likely to develop in participants in the lowest tertile vs the highest tertile of vitamin E intake (adjusted hazard ratio, 0.75; 95% confidence interval [CI], 0.59-0.95).
After multivariate adjustment, dietary intake of vitamin C, beta carotene, and flavonoids were not linked to dementia risk. Findings were similar for AD risk.

Viewpoint

Compared with previous research, important contributions of this study are population-based estimates of incident dementia risk over a decade, evaluation of food-based antioxidants typically found in a Western-type diet, and assessment of various antioxidants and total vitamin E, including all 8 forms.

Despite study limitations of observational design with possible residual confounding, the findings suggest a modest reduction in long-term risk for dementia and AD associated with increased consumption of vitamin E-rich foods. Although an earlier study suggested a possible inverse association between vitamin C intake and dementia risk, this was not observed in this study.
A possible explanation is that intake of different antioxidants may affect risk at different time points in the course of dementia, supporting the need for additional research to address this question.

Abstract