Vitamin E or C does not reduce risk of dementia or Alzheimer's

February 4, 2008

Contrary to previous research, older adults who use over-the-counter vitamin E or C supplements do not have a reduced risk of developing dementia or Alzheimer’s disease. This is according to a new study published in the Journal of the American Geriatrics Society that tracked patients using vitamin E and/or vitamin C supplements over a follow-up period of more than 5 years.

The study also finds that the combined use of vitamins E and C, which was previously thought to offer even greater protection against the diseases, also did not reduce the risk of developing dementia or Alzheimer’s.

“There is limited evidence to support supplemental use of the vitamins to prevent or delay onset of Alzheimer’s disease, says Shelly L. Gray, author of the study. “In fact, other studies show that higher doses of vitamin E may even be associated with harm in older people, such as slightly increased risk of mortality.”

The exact cause of Alzheimer’s disease is not entirely known. One theory is that a high level of free radicals in the brain may contribute. Some vitamins, such as vitamin E, have the ability to neutralize free radicals, which might be expected to prevent injury to cells in the body that lead to disease. By taking doses of vitamin E that are higher than recommended for normal functioning of the body, it was hoped that cell injury from oxidant stress may be prevented, and that effect, if present, would result in less chance of developing Alzheimer’s.

Some older adults purchase even higher doses of vitamins E and C in the hope that they will prevent such diseases. The doses found in these supplements may be much higher than what is recommended for use by the general public and what is usually contained in a multivitamin.

At one point, vitamin E was touted as beneficial for preventing a wide variety of diseases and, therefore, this agent is still widely used. However, a growing body of evidence suggests that vitamin E also does not protect against cardiovascular disease or the many cancers thought to be inhibited through vitamin E intake. Many older adults may still believe that vitamin E is beneficial and may still be taking higher doses in hope of maintaining memory. Because vitamin E does not dissolve in water but instead in fat, it is harder for the body to rid itself of excess amounts of the vitamin.

Source: Blackwell Publishing Ltd.