Folic acid may reduce Alzheimer risk
Consuming enough of the B vitamin folic acid significantly reduces the risk of Alzheimer's disease, according to a study appearing in the July issue of Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
"This report bolsters evidence that adequate folic acid may help the brain, nervous system and heart and blood vessels in a variety of ways," says William H. Thies, Ph.D., Alzheimer's Association vice president, medical and scientific affairs. "Since 1998, breads, cereals and other grain products have been fortified with folic acid in the United States to reduce the likelihood of serious nervous system birth defects. It's looking increasingly as if folic acid remains important for brain health throughout life."
This study, published in the inaugural issue of the Alzheimer's Association official journal, found that older adults who consume at least the recommended dietary allowance (RDA) of 400 micrograms of folic acid per day reduced their risk of Alzheimer's by more than 50 percent. There was little added benefit from folic acid intake much above the RDA. Most study participants who met or exceeded the RDA did so through a combination of foods and supplements. Foods rich in folic acid include fortified bread products, green leafy vegetables, fruits, whole grains, and peas and beans.
Researchers analyzed diet and supplement use for 579 participants in the Baltimore Longitudinal Study of Aging, a long-running federally funded investigation of the effects of growing older, and then followed them for an average of nine years to track incidence of Alzheimer's disease.
Adequate folic acid has also been shown to lower levels of the protein building block homocysteine. Elevated homocysteine is a risk factor for heart attacks and diseases of the blood vessels and possibly Alzheimer's disease.
A June 2005 report at the Alzheimer's Association International Conference on Prevention of Dementia linked daily doses of 800 micrograms of folic acid (twice the RDA) to better performance on tests of memory, reaction time and thinking speed for older adults. That study was not designed to show whether folic acid had any benefit in preventing dementia.
The Baltimore Longitudinal Study of Aging is funded by the National Institute on Aging (NIA), the agency of the National Institutes of Health (NIH) that funds most research on aging and dementia.
For more information, please see:
- The Alzheimer's Association press release on this study
- A June 28, 2005, Alzheimer's Association research news feature on the study linking high folic acid intake to better performance on memory and thinking tests
- Alzheimer's Association Maintain Your Brain®, a public education campaign to raise awareness of dietary measures and other brain health strategies
- The section of our Web site on Alzheimer's & Dementia: The Journal of the Alzheimer's Association