Information about the Antioxidant Vitamin E, Eldepryl, and Alzheimer's Disease Treatment

The antioxidant properties of vitamin E made it the focus of a well-designed study published in The New England Journal of Medicine in 1997. In that study, people with moderately severe Alzheimer's disease were assigned to one of four treatment groups: a daily dose of 2,000 IU of vitamin E, 10 mg a day of selegiline (Eldepryl, a medication used to treat Parkinson's disease), a combination of vitamin E and Eldepryl, or a placebo. Taking either vitamin E or Eldepryl prolonged the time before institutionalization became necessary and increased survival by about seven months.

Furthermore, vitamin E and Eldepryl when taken independently reduced—by 25%—the number of people who lost the ability to perform daily activities, such as handling money or bathing. Unfortunately, combining vitamin E and Eldepryl did not further improve results.

On the basis of this study, the American Academy of Neurology concluded that sound evidence supports the use of vitamin E in an attempt to slow the progression of Alzheimer's disease. The evidence for Eldepryl is weaker, and the drug has more side effects than vitamin E. Furthermore, if vitamin E is already being used, Eldepryl offers no additional advantage.

It is not clear whether vitamin E can help forestall dementia among high-risk individuals. The much-anticipated preliminary results of the Memory Impairment Study were disappointing in that regard. The study was a randomized, placebo-controlled trial of vitamin E and the cholinesterase inhibitor Aricept.

It was designed to determine whether Aricept or vitamin E could slow progression to Alzheimer's disease among individuals with mild cognitive impairment. The study found no benefit to vitamin E supplementation. Despite this setback, researchers are continuing to study vitamin E and its potential for warding off dementia.

Although vitamin E is generally safe, large doses can increase the risk of bleeding, especially in some people who are deficient in vitamin K. Take vitamin E supplements only under your doctor's supervision.

Publication Review By: Peter V. Rabins, M.D., M.P.H.

Published: 11 Mar 2011

Last Modified: 23 Jun 2011