Benefits of 'B's' Unsettled
WebMD News Archive
The study began in 1993 with nearly 750 patients who had some evidence of
heart disease that occurred before they were 56 years old. The researchers then
sought out the siblings of these individuals, and screened them for high levels
of homocysteine. A total of 450 siblings were screened for this protein, but
the final study sample was much smaller -- 80 joined the placebo group and 78
were placed in the treatment group. The treatment group received 250 mg of
vitamin B6 and 5 mg of folic acid daily for two years.
At the end of the two years, those in the treatment group were 60% less
likely than those in the placebo group to have abnormal tests during stressful
exercise. There was no change in other tests that measure heart function.
In his editorial, Bostom said the study size was too small to be significant
and called the use of stress exercise tests questionable. Bostom says studies
underway in the U.S. and Europe will indicate whether lowering homocysteine
levels with B vitamins actually results in fewer heart problems. Until then, he
advises "watching and waiting" and does not recommend that people take
higher than recommended doses of B6 and folic acid.
Stehouwer, in contrast, says he sees little peril in suggesting that people
who are at increased risk of heart disease consume B6 and folic acid, a
practice he says his hospital has adopted. If results from future studies
indicate little value, the vitamins can easily be stopped, he says. "What
we used were a bit higher than what it the common dose. We believe the chances
of doing harm are fairly remote."
But another researcher currently studying this issue feels there is some
danger from this study. Charles Hennekens, MD, tells WebMD he fears such
studies will prompt people to abandon the more difficult -- but proven --
lifestyle changes they should be making to reduce their risk of heart
"It is premature to begin to tell people to take folic acid [and vitamin
B6] to prevent heart disease, but we can't sweep suggestions that high levels
of homocysteine are correlated to heart disease," says Hennekens, a
visiting professor in the department of epidemiology and public health at the
University of Miami. "But these are research questions, not public policy
questions. We have a population in the U.S. that prefers prescription of
drugs, rather than proscription of lifestyle modifications. If people,
hearing the news, relax their efforts at reducing cigarette smoking, reducing
obesity, reducing physical inactivity ... that could do damage."