Benefits of 'B's' Unsettled
WebMD News Archive
Feb. 10, 2000 (Washington) -- One day it may be proven that taking vitamins
reduces the risk of heart disease, but today is not that day -- despite a Dutch
study that showed a 60% reduction in abnormal heart stress tests in people who
took vitamin B6 and folic acid for two years, compared to a group who took a
placebo. That study, published in Feb. 12 issue of the journal The
Lancet, is too small to be conclusive and used measurements of heart health
that are fraught with inaccurate results, experts tell WebMD.
Some researchers have come to suspect that high levels of a naturally
occurring protein, homocysteine, put people at increased risk for heart
problems. The tantalizing, but yet unproven, theory is that the use of simple B
vitamins, specifically B6 and folic acid, can reduce these homocysteine
concentrations and thwart heart problems. Studies are underway that look at
whether these supplements result in reduced numbers of heart attacks, strokes,
and other related problems.
The Lancet study also tries to prove this theory, but the Dutch
researchers looked at how well their study participants did on exercise stress
tests, which are notoriously inaccurate.
"I think this tells us nothing and I am afraid people will misinterpret
it," Andrew G. Bostom, MD, tells WebMD. Bostom, an assistant professor at
Brown University in Providence, R.I., wrote an editorial critical of the study
that also appears in the publication. "They can stand on their heads and
spit nickels in the Netherlands about the editorial. But this study still means
nothing. It is not a valid design and three of the four things they studied
showed no result," he says.
A co-author of the study, however, defended it as an "important first
step." Says Coen Stehouwer, MD, "This is the first investigation that
has provided some ... proof of the concept. This is only the first step. We
clearly do not want to claim that this is all settled, but it is an important
step. It is encouraging," though more conclusive proof will come from large
studies, he says. Stehouwer is an assistant professor of internal medicine at
University Hospital Vrije Universiteit in Amsterdam.
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.