B Vitamins Fail to Prevent

B Vitamins Fail to Prevent Alzheimer’s

Many
people take B vitamins in the hopes of warding off Alzheimer’s disease
and keeping the mind sharp. But a new analysis found that taking B
vitamins did not slow mental decline with aging or prevent the onset of
Alzheimer’s.

The analysis reviewed data from 11 earlier studies involving more
than 22,000 older men and women. Most of the participants were in their
60s or 70s and free of dementia at the start of the studies. In some of
the studies, participants took B vitamins, while others took look-alike placebo pills, for an average of about five years.

B vitamins are known to promote nerve health and are critical for
development of the brain and nervous system. Some earlier studies have
shown that B vitamins lower blood levels of homocysteine, a protein
known to raise the risk for heart disease and Alzheimer’s. People with
Alzheimer’s often have high levels of homocysteine in their blood.

The current analysis found that taking B vitamins reduced levels of
homocysteine by about 25 percent. But this did not translate into
improved thinking and memory skills with age. The research was carried
out by the B-Vitamin Treatment Trialists' Collaboration, an
international group of scientists. It was published in the American
Journal of Clinical Nutrition.

“It would have been very nice to have found something different,”
said Dr. Robert Clarke of Oxford University, who led the work. “Our
study draws a line under the debate: B vitamins don't reduce cognitive
decline as we age. Taking folic acid and vitamin B-12 is sadly not going
to prevent Alzheimer's disease.”

“Much better is to eat more fruit and vegetables, avoid too much red
meat and too many calories, and have a balanced diet,” Dr. Clarke added.
Other studies suggest that a Mediterranean style diet, rich in fish,
fresh fruit and vegetables, whole grains and heart-healthy olive oil, is
good for the brain.

There are many types of B vitamins, and all are important for the
healthy functioning of the brain and nervous system. After age 50, some
people have trouble absorbing B vitamins from foods, particularly
vitamin B12, and supplements are recommended. Women are advised to take
folic acid before and during pregnancy to lower the risk of
nerve-related birth defects in their children.

But for most people, taking B vitamin pills will do little to improve
brain health or prevent the onset of Alzheimer’s disease. The findings
underscore the importance of new research to find new and more effective
treatments for Alzheimer’s disease.

By www.ALZinfo.org, The Alzheimer's Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer's Research Foundation at The Rockefeller University.

Source: Clarke R, Bennet D, Parish S: “Effects of homocysteine
lowering with B vitamins on cognitive aging: meta-analysis of 11 trials
with cognitive data on 22,000 individuals.” American Journal of Clinical Nutrition, Vol. 100, August 2014, pages 657-666.