Vitamin B Slows Brain Shrinkage in Study That May Aid Alzheimer's Research

Taking vitamin B slowed the rate that the brain shrank in elderly people who had trouble remembering, University of Oxford scientists found in a study that may guide further research into Alzheimer’s disease.

Vitamins B6 and B12, as well as folic acid, lowered the levels of an amino acid called homocysteine that is linked to brain-cell damage similar to that seen in Alzheimer’s. Those with the highest levels of homocysteine in their blood showed the most benefit, according to the study published today in PLoS One, a publication of the Public Library of Science.

The findings suggest that vitamin treatment may slow development of Alzheimer’s. There is no cure, and drugs have been proven only to ease symptoms. Alzheimer’s and other dementias will afflict 35.6 million people in 2010, and cases will rise to 115.4 million by 2050, according to a report from Alzheimer’s Disease International, based in London.

“These are immensely promising results, but we do need to do more trials to conclude whether these particular B vitamins can slow or prevent development of Alzheimer’s,” said David Smith, a co-leader of the study and a professor of pharmacology at Oxford, in the U.K., in a statement. “I wouldn’t yet recommend that anyone getting a bit older and beginning to be worried about memory lapses should rush out and buy vitamin B supplements.”

Conflicting Results

The results from the Public Library of Science, a nonprofit organization based in San Francisco, conflict with earlier findings that Alzheimer’s disease patients didn’t benefit from the vitamin. A study of 340 patients with mild-to-moderate Alzheimer’s, published by the Journal of the American Medical Association in 2008, found no difference in the decline of patients’ memory, attention, language or orientation among people with mild to moderate forms of the disease, regardless of whether they took vitamin B.

The Oxford study included 168 people, ages 70 and up, with mild memory problems. Half of them took 0.8 milligram of folic acid, 0.5 milligram of B12 and 20 milligrams of B6 every day for two years, and the rest were given a placebo.

The researchers gauged the disease using magnetic resonance imaging technology to measure the rate at which the brain shrank over the course of the study. Those who took folic acid, vitamin B6 and B12 had their brains shrink by 0.76 percent a year on average, while those on placebo had an atrophy rate of 1.08 percent, according to the study.

‘A Step Closer’

“This trial brings us a step closer to unraveling the complex neurobiology of aging and cognitive decline, which holds the key to the development of future treatments for conditions like Alzheimer’s disease,” said Chris Kennard, chairman of the London-based U.K. Medical Research Council’s Neurosciences & Mental Health Board, in a statement.

The research was funded by the Medical Research Council, a publicly financed organization focused on human health; the Charles Wolfson Charitable Trust, a Worcester, England-based organization that advocates for medical research and education; the Alzheimer’s Research Trust in Cambridge, England; the London-based Henry Smith Charity, a 382-year-old group that supports projects that address social inequality and economic disadvantage; the John Coates Charitable Trust of Cambridge, England, which funds education, conservation and research; the National Institute for Health Research in London; and the Sidney and Elizabeth Corob Charitable Trust, also in London.

Meda AB, a Solna, Sweden-based drugmaker, also contributed to the study.

Impaired Memory

About 1 in 6 people over age 70 has trouble with memory, language or other mental functions, according to the researchers. Half of those with some impairment develop dementia, mainly Alzheimer’s, the scientists said.

A dozen potential medicines designed to slow or stop clumps of protein from forming in the brain, a condition linked to Alzheimer’s, have failed in mid- to late-stage human tests since 2003.

Taking some medications, such as the ulcer pill Nexium from AstraZeneca Plc in London and the anti-epilepsy drug phentytoin, may affect the absorption of vitamin B by the body, according to the U.S. National Institutes of Health in Bethesda, Maryland.

Family history, alcohol consumption, education levels and head injuries may have an effect on the development of dementia later in life, according to Alzheimer’s Disease International, a federation of 71 Alzheimer’s advocacy groups based in London.

To contact the reporter on this story: Kristen Hallam in London at khallam@bloomberg.net

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