listener medicine forum Guru
Joined: 05 May 2005
Posts: 617
|
Posted: Thu Jun 29, 2006 12:06 am Post subject:
Vitamins failed to slow mental decline in study
|
|
|
BOSTON (Reuters) - Vitamin therapy failed to slow the mental decline of
older people who have high levels of an amino acid that has been associated
with cognitive disorders, according to a new clinical trial.
The results, published in The New England Journal of Medicine showed that
127 volunteers aged over 64 and with high levels of homocysteine who took
vitamin therapy for two years had lower levels of the amino acid but
performed no better in cognitive tests than 126 who received a placebo.
"The results of our trial do not support the hypothesis that homocysteine
lowering with folate, vitamins B-12, and B-6 improves cognitive performance
in healthy older people," said a New Zealand team led by Jennifer McMahon
of the University of Otago.
Earlier studies have shown that people with declining mental abilities tend
to have high levels of the chemical. But it has been unclear whether using
folic acid and B vitamins to bring the levels down would prevent or delay
the deterioration. The McMahon study was an attempt to find out.
In an editorial in the New England Journal of Medicine, where the study
appears, Robert Clarke of the University of Oxford said that the experiment
didn't have enough volunteers, didn't last long enough, and the mental
sharpness of the people who received the placebo tablets didn't deteriorate
fast enough to prove that the vitamins failed to affect the risk of
dementia.
He said forthcoming results from about 20,000 people from a dozen studies
on volunteers with heart or kidney disease may offer better evidence in the
coming years.
This is the third study since March to question the benefits of reducing
homocysteine levels. Two tests, also published in the New England Journal,
showed that using B vitamins and folic acid to treat people with high
homocysteine levels did not bring down their elevated risk of heart attack
or stroke. |
|