Can Vitamin E Supplements Prevent Dementia? | Alzheimer's Prevention Registry

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July 20, 2017

Can Vitamin E Supplements Prevent Dementia?

By Alzheimer's Prevention Bulletin

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For years, the public has been excited by the possibility that antioxidant supplements could prevent dementia due to Alzheimer’s disease. Many even began taking vitamin E and selenium antioxidant supplements in the hopes additional research would confirm the benefits of antioxidants. 

How did antioxidant supplements – and specifically vitamin E and selenium – become associated with fighting the aging process and protecting nerve cells from deterioration? Years ago, studies on animals showed vitamin E helped protect their neurons from damage. Fast forward to more recent clinical trials of vitamin E on people and the results are mixed. One study supported vitamin E’s protective qualities while the others came up short. Selenium study findings were also inconsistent.

The results of the recently released PREADViSE trial – Prevention of Alzheimer’s Disease by Vitamin E and Selenium – seem to definitively answer the question about the benefits of vitamin E and selenium. The trial included 7,540 men who were enrolled in a much larger trial studying if these same antioxidants could reduce the rate of prostate cancer. That study ended early when findings showed the antioxidants would never improve prostate cancer rates. However, the study looking at whether antioxidants reduced dementia continued. 

“There are several ways that prevention trials are conducted,” said Lon S. Schneider, MD, MS, Director, Clinical Core, University of Southern California, Alzheimer’s Disease Research Center. “One is to design a prevention study from the bottom up, like the Generation Study. The other way is to piggyback on an existing study, which is the approach PREADViSE took.”

PREADViSE compared trial participants who took specific doses of the supplements –vitamin E, selenium, and vitamin E combined with selenium – to the group taking a placebo. The number of years the men took the supplements varied from one to seven. An analysis of the dementia risk between the groups showed no difference in dementia risk. This led PREADViSE researchers to conclude that vitamin E and selenium supplements do not prevent dementia.

However, don’t give up on vitamin E and selenium altogether. Antioxidants have other health benefits. And the best way to get both antioxidants is through your diet. So put aside the supplements and pass the sunflower seeds, broccoli and tomatoes—just a few antioxidant-rich foods you can include in your diet for overall health.