Folic Acid May Slow Mental Decline, Scientists Say

WASHINGTON - Middle-age people who were treated with the B-vitamin folic acid substantially improved their cognitive test scores, essentially performing as though they were two to five years younger, according to a new study.

"It's the first study to convincingly show that folic acid can slow cognitive decline," said lead author Jane Durga, a researcher with Wageningen University in the Netherlands. "We showed that folic acid, not a mix of B vitamins, can do the job."

The research involved one of several promising therapies that were presented at an Alzheimer's prevention meeting in Washington Monday. The studies suggest there are new ways to attack Alzheimer's disease using differing strategies, according to Steven DeKosky, director of the Alzheimer's Disease Research Center at the University of Pittsburgh and a spokesman for the Alzheimer's Association.

The folic acid study involved 818 men and women ages 50 to 70 in the Netherlands who had elevated levels of homocysteine, an amino acid found in the blood that has been implicated in heart disease and stroke.

They were given 800 micrograms of folic acid or a placebo daily for three years. Multivitamins generally have 400 micrograms of folic acid.

After cognitive testing, the subjects who received folic acid showed improvement in memory, equivalent to being 5.4 years younger; information processing, 2.0 years younger; and sensory motor speed, 1.9 years younger. The sensory motor speed tests involved the speed of reading a list of words under varying conditions.

Durga said that homocysteine dropped an average of 26 percent.

"You like to see this kind of study," said Ronald Petersen, a professor of neurology at the Mayo Clinic, who was not associated with the study.

He noted that homocysteine already has been implicated in Alzheimer's disease, and that folic acid is an inexpensive and relatively safe vitamin.

However, because the people in the study did not have Alzheimer's disease, it is not known how much, if at all, Alzheimer's patients might benefit from folic acid. What is needed now is a larger clinical trial of people who have the disease, are at risk for the disease or have mild cognitive impairment, a condition that often leads to Alzheimer's, Petersen said.

Such a trial now is being sponsored by the National Institutes of Health. The trial is using mega high-dose folic acid and vitamins B-6 and B-12, which also can lower homocysteine, to see if the vitamins can slow the rate of mental decline in people with Alzheimer's. The trial is expected to be completed in February.

"There is some evidence that it (homocysteine) is a neurotoxic compound in the brain," said Neil Buckholtz, chief of the dementias of aging branch of the National Institute on Aging, part of NIH.

He said the Dutch study expands on existing research.

"It's very encouraging," he said.

In a separate study, researchers from the University of Washington School of Medicine presented the results of a trial using an insulin nasal spray on 26 people with either early Alzheimer's or mild cognitive impairment.

Earlier research has implicated insulin resistance in Alzheimer's. Insulin can enhance memory and the regulation of important brain chemicals.

It is believed that high levels of insulin in the blood, which is common in people who are insulin resistant, make it more difficult for insulin to carry out its function in the brain, said lead author Suzanne Craft, a professor of psychiatry at the University of Washington.

"It is possible that raising brain insulin levels ... can have beneficial effects," Craft said.

The researchers used a nasal spray that sent the insulin directly into the brain and not the body, to prevent a troublesome drop in blood sugar. Fifteen minutes after getting the nasal spray, the memory of the patients was tested.

Memory improved significantly in those who did not have a genetic trait that put them at higher risk for Alzheimer's. That trait is found in about half of all Alzheimer's cases and 14 percent of the overall U.S. population.

In those who had the gene, there was no improvement. Craft said it is still possible that insulin may be beneficial to those patients once a correct dose is determined.

Another trial involved the drug R-flurbiprofen, a modified version of an anti-inflammatory painkiller. The drug has been shown to reduce levels of amyloid-beta, a protein that accumulates in the brains of people with Alzheimer's.

The study involved 207 people with mild to moderate Alzheimer's.

Over the course of a year, the drug significantly slowed cognitive decline in those with mild Alzheimer's.

"The moderate subjects didn't seem to benefit," said the lead author, Gordon Wilcock, at the University of Bristol in the United Kingdom. "The earlier we can diagnose Alzheimer's, the better."

The studies were presented at the first International Conference on Prevention of Dementia presented by the Alzheimer's Association.

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TURNING BACK THE CLOCK?

In a study from the Netherlands, middle-age people who took a daily dose of folic acid showed results equivalent to being younger than their age in these cognitive areas:

-5.4 years younger for memory

-2.0 years for information processing

-1.9 years for sensory motor speed

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(c) 2005, Milwaukee Journal Sentinel. Distributed by Knight Ridder/Tribune News Service.

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