B Vitamins May Cut Stroke Risk
Study Shows High Doses May Reduce Incidence of Stroke in People at High Risk
WebMD News Archive
Feb. 20, 2009 (San Diego) -- High doses of B vitamins may help prevent
stroke in high-risk people, new research suggests.
The finding comes from the Heart Outcomes Prevention Evaluation 2 trial of
more than 5,500 men and women with heart disease. Participants were assigned to
a daily regimen of either B vitamins or placebo pills for five years.
Results showed that people who took the vitamins were 25% less likely to
suffer a stroke over the study period than those who took placebo.
People younger than 70, those not taking cholesterol-lowering statin drugs
or blood thinners, and those living in regions without folic acid food
fortification appeared to gain the greatest benefit.
But taking vitamins did not have any effect on the severity of stroke or any
associated disabilities, says researcher Gustavo Saposnik, MD, of the
University of Toronto.
He presented the findings at the International Stroke Conference 2009.
B Vitamins Lower Homocysteine
B vitamins lower blood levels of a compound called homocysteine. The risk of
heart disease and stroke is increased when a person has high blood levels of
homocysteine, so it follows that taking B vitamins to lower homocysteine levels
would improve outcomes.
But until now, researchers have had little success trying to show that.
Study after study has failed to show that B vitamins prevent heart disease
or stroke, says ASA spokesman Larry B. Goldstein, MD, director of the Duke
Stroke Center at Duke University, in Durham, N.C.
"We need to sift through all the studies and try to figure out why the
results are conflicting," he tells WebMD. Until then, Goldstein does not
recommend taking vitamins to prevent cardiovascular disease.
Saposnik says he thinks his study is the first to "use an adequate
dose" of vitamin B12 to lower homocysteine and stroke levels. The daily
vitamin regimen in the new study involved 2.5 milligrams of folic acid, 50
milligrams of vitamin B6, and 1 milligram of vitamin B12 -- far more than most
people get in their diets.
Still, Saposnik agrees with Goldstein that further study is needed before
any firm conclusions can be drawn.