by Dr. Meenakshy Varier on  March 20, 2017 at 9:16 PM Health Watch
  • Oxidative stress, that arises due to excess production of oxygen free radicals, has been implicated in the dementia pathway.
  • Antioxidants were of interest in the treatment of dementia, due their potential to neutralize free radicals.
  • Recent findings suggest that antioxidants do not play any role in preventing dementia.

Antioxidants Fail to Lower Dementia Risk
Antioxidant supplements vitamin E and selenium taken alone or in combination did not prevent dementia in asymptomatic older men.

Oxidative stress has been implicated in the dementia pathway and the use of antioxidants as a potential treatment for cognitive impairment or dementia has been of interest.

Oxidative stres arises due to the imbalance between the production of free radicals and the ability of the body to destroy them.

Free radicals can cause severe damage to the cell. Antioxidants are thought to neutralize free radicals.

The Prevention of Alzheimer's Disease by Vitamin E and Selenium (PREADViSE) clinical trial initially enrolled 7,540 older men who used the supplements for an average of about five years and a subset of 3,786 men who agreed to be observed longer.

The men were divided into four groups that received:
  • vitamin E
  • selenium
  • both
  • placebo
According to the findings, the incidence of dementia (325 of 7,338 men [4.4%]) was not different among the four study groups.

The main limitation of the study include losing about half of the participants to long-term follow-up during the transition from a randomized clinical trial to a cohort study.

"The supplemental use of vitamin E and selenium did not forestall dementia and are not recommended as preventive agents. This conclusion is tempered by the underpowered study, inclusion of only men, a short supplement exposure time, dosage considerations and methodologic limitations in relying on real-world reporting of incident cases," the article concludes.

The study was conducted by Richard J. Kryscio, Ph.D., of the University of Kentucky, Lexington, and coauthors and published online in JAMA Neurology.


  1. What is Oxidative Stress? - (

Source: Medindia

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