High Folate Intake Reduces Risk of Alzheimer's disease

[Guest guest]

12 Aug 2005

 

 

 

 

 

Major observational study points to importance of healthy diet for

long-term brain health -

 

Adults who eat the daily recommended allowance of folates -- B-

vitamin nutrients found in oranges, legumes, leafy green vegetables

and folic acid supplements -- significantly reduce their risk of

developing Alzheimer's disease, according to results from a long-term

National Institute on Aging study of diet and brain aging.

 

The study also found that folates appear to have more impact on

reducing Alzheimer's risk than vitamin E, a noted antioxidant, and

other nutrients considered for their effect as a brain-aging

deterrent.

 

Maria Corrada and Dr. Claudia Kawas of UC Irvine's Institute for

Brain Aging and Dementia led the effort, which analyzed the diets of

non-demented men and women age 60 and older. They compared the food

nutrient and supplement intake of those who later developed

Alzheimer's disease to the intake of those who did not develop the

disease. It is the largest study to date to report on the association

between folate intake and Alzheimer's risk and to analyze

antioxidants and B vitamins simultaneously.

 

Results appear in the inaugural issue of the quarterly peer-reviewed

research journal, Alzheimer's & Dementia: The Journal of the

Alzheimer's Association.

 

" Although folates appear to be more beneficial than other nutrients,

the primary message should be that overall healthy diets seem to have

an impact on limiting Alzheimer's disease risk, " said Corrada, who

like Kawas started with the study while at Johns Hopkins University

in Baltimore.

 

The researchers used data from the Baltimore Longitudinal Study of

Aging to identify the relationship between dietary factors and

Alzheimer's disease risk. Between 1984 and 1991, study volunteers

provided detailed dietary diaries, which included supplement intake

and calorie amounts, for a typical seven-day period.

 

Ultimately, 57 of the original 579 participants developed Alzheimer's

disease. But the researchers found that those with higher intake of

folates, vitamin E and vitamin B6 shared lower comparative rates of

the disease. And when the three vitamins were analyzed together, only

folates were associated with a significantly decreased risk.

 

In turn, no association was found between vitamin C, carotenoids

(such as beta-carotene) or vitamin B-12 intake and decreased

Alzheimer's risk.

 

" The participants who had intakes at or above the 400-microgram

recommended dietary allowance of folates had a 55-percent reduction

in risk of developing Alzheimer's, " said Corrada, an assistant

professor of neurology. " But most people who reached that level did

so by taking folic acid supplements, which suggests that many people

do not get the recommended amounts of folates in their diets. "

 

Folates have already been proven to reduce birth defects, and

research suggests that they are beneficial to warding off heart

disease and strokes. Although folates are abundant in foods such as

liver, kidneys, yeast, fruits (like bananas and oranges), leafy

vegetables, whole-wheat bread, lima beans, eggs and milk, they are

often destroyed by cooking or processing. Because of their link to

reducing birth defects, folates have been added to grain products

sold in the U.S. since 1998. But even with this supplement, it is

thought that many Americans have folate-deficient diets.

 

Recent research is beginning to show relationships between folates

and brain aging. Earlier this year, Dutch scientists showed that

adults who took 800 micrograms of folic acid daily had significant

improved memory test scores, giving evidence that folates can slow

cognitive decline. " Given the observational nature of this study, it

is still possible that other unmeasured factors also may be

responsible for this reduction in risk, " said Kawas, the Al and Trish

Nichols Chair in Clinical Neuroscience. " People with a high intake of

one nutrient are likely to have a high intake of several other

nutrients and may generally have a healthy lifestyle. But further

research and clinical studies on this subject will be necessary. "

 

Judith Hallfrisch of the U.S. Department of Agriculture, Denis Muller

with the National Institute on Aging and Ron Brookmeyer with Johns

Hopkins collaborated on the study, which was originally undertaken at

the Gerontology Research Center of the NIA and the Department of

Neurology at Johns Hopkins. Study funding came from the Extramural

Programs of the NIA.

 

Begun in 1958 by the NIA, the Baltimore Longitudinal Study of Aging

is America's longest-running scientific study of human aging. BLSA

scientists are learning what happens as people age and how to sort

out changes due to aging from those due to disease or other causes.

More than 1,400 men and women are study volunteers. For more

information, see: grc.nia.nih.gov/branches/blsa/blsa.htm.

 

About the University of California, Irvine: Celebrating 40 years of

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of California campuses, with more than 24,000 undergraduate and

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To access, visit http://www.today.uci.edu/experts.

 

Tom Vasich

tmvasich

949-824-6455

University of California - Irvine

http://www.uci.edu