Boost your memory
2007-11-13 07:25
Washington - Beta carotene taken as
a dietary supplement for many years may protect against
declines in memory, thinking and learning skills that often
precede Alzheimer's disease, researchers said on Monday.
The study, published in the Archives of Internal Medicine,
pointed to a protective effect against cognitive decline in
healthy men who took beta carotene for about 18 years, but not
in men who took the supplements for an average of a year.
The findings indicate beta carotene may be an important
weapon in warding off memory problems that may foreshadow
Alzheimer's and other forms of dementia, the researchers said.
"This is the first trial that has found any way to help
your memory if you're healthy. I think it does tell us that we
can change how our memory improves or worsens," Francine
Grodstein of Brigham and Women's Hospital in Boston, who led
the study, said.
Taking beta carotene may have risks for some people such as
raising lung cancer risk in smokers, Grodstein said.
Beta carotene is one of the antioxidants - substances that
prevent some of the damage from unstable molecules known as
free radicals - created when the body turns food into energy.
Some experts think antioxidants can lower the risk of cancer,
heart disease and other ailments.
Higher scores for long-term users
"Beta carotene is an antioxidant vitamin. So the reason we
thought it might help your brain is because there is now a lot
of evidence that oxidative damage harms your brain. And that
may be one of the initiating factors which leads to memory
problems," Grodstein said.
In this study, researchers examined the effects of beta
carotene on cognitive ability in two groups of men.
Those in a group of 4 052 men were randomly assigned in
1982 to take either 50 milligrams of beta carotene or a placebo
every other day. Another 1 904 men between 1998 and 2001 were
also randomly assigned to take either the same amount of beta
carotene or a placebo every other day.
The men in the long-term group took the supplements for an
average of 18 years. The men in the short-term group did so for
an average of a year, with the longest being three years.
Men who took beta carotene in the long-term group recorded
significantly higher scores on several cognitive tests -
particularly tests of verbal memory - compared with those who
took a placebo, the study found. In the short-term group, the
men taking beta carotene did no better in cognitive tests.
In an editorial accompanying the study, Dr Kristine Yaffe
of the San Francisco Veterans Affairs Medical Centre and
University of California at San Francisco sounded a note of
caution, saying studies have yielded mixed results about
antioxidant supplements and better cognitive outcomes.
"For the clinician, there is no convincing justification to
recommend the use of antioxidant dietary supplements to
maintain cognitive performance in cognitively normal adults or
in those with mild cognitive impairment," Yaffe wrote.