An update on using vitamin E in Alzheimer's disease.

Background: Oxidative stress represents a key event in the pathogenesis of Alzheimer's disease (AD). Low circulating concentrations of vitamin E, quantitatively the major lipophilic antioxidant in the brain, are frequently observed in AD patients, suggesting that supplementation with vitamin E may delay the development of AD.

Objectives: To assess the value of therapeutic use of vitamin E in AD.

Method: Search of the PubMed and Medline online libraries for relevant English-language publications between 1966 and 2007.

Results And Conclusions: Supplementation of AD patients with vitamin E increases its levels in biological fluids and decreases their susceptibility to oxidative stress. However, clinical interventional and observational studies demonstrated contradicting results regarding the benefit of vitamin E in AD. Available data do not provide any clear evidence that vitamin E beneficially influences AD and are not sufficient to recommend vitamin E for primary or secondary prevention of AD. The future of vitamin E supplementation in AD should be therefore regarded with caution.