Serum lycopene, lutein and zeaxanthin, and the risk of Alzheimer's disease mortality in older adults.

Abstract

BACKGROUND: Oxidative stress is implicated in the pathogenesis of Alzheimer's

disease (AD). Accumulating evidence shows that antioxidant-rich food reduces the

risk of AD by inhibiting oxidative stress. This study investigates whether serum

levels of carotenoids were associated with the risk of AD mortality in a

nationally representative sample of US adults. METHODS: We used data from the

Third Nutrition and Health Examination Survey (NHANES III) database and the

NHANES III Linked Mortality File. A total of 6,958 participants aged older than

50 years were included in this study. RESULTS: We found that high serum levels of

lycopene and lutein+zeaxanthin at baseline were associated with a lower risk of

AD mortality after adjustment for potential covariates. The reduction in the

mortality risk was progressively raised by increasing serum lycopene (HR = 0.26,

95% CI 0.10-0.69) and lutein+zeaxanthin (HR = 0.43, 95% CI 0.22-0.85) levels. In

contrast, no associations with AD mortality were observed for other serum

carotenoids, including alpha-carotene, beta-carotene, and beta-cryptoxanthin.

CONCLUSION: High serum levels of lycopene and lutein+zeaxanthin are associated

with a lower risk of AD mortality in adults. Our findings suggest that a high

intake of lycopene- or lutein+zeaxanthin-rich food may be important for reducing

the AD mortality risk.