Dietary Intakes of Vitamin E, Vitamin C, and beta-Carotene and Risk of Alzheimer's Disease: A Meta-Analysis

In view of the vital role of oxidative stress in the pathogenesis of Alzheimer's disease (AD), the potential of antioxidant supplements to prevent AD have gained much interest, while there are conflicting results on this topic in recent years. The purpose of the present study is to comprehensively evaluate the association between dietary intakes, instead of supplements, of the most common three antioxidants (vitamin E, vitamin C, and beta-carotene) and the risk of AD on the basis of the meta-analysis studies published up to October 2011 in Medline and Scopus databases. In total, seven articles were included in the meta-analysis. According to the pooled relative risk [(95% CI) 0.76 (0.67-0.84) for vitamin E, 0.83 (0.72-0.94) for vitamin C, and 0.88 (0.73-1.03) for beta-carotene], dietary intakes of the three antioxidants can lower the risk of AD, with vitamin E exhibiting the most pronounced protective effects. The findings will be of significance to the prevention and interventional treatment of AD.