Doctors had hoped that women who took daily supplements of folic acid and other B vitamins could lower their risk for heart attacks and strokes, but the strategy turned out to be a major flop in a recent study.
Folic acid, vitamin B6 and vitamin B12 reduce blood levels of a substance called homocysteine, high concentrations of which have been linked with a greater risk for heart disease.
Dr. Christine Albert, the lead study investigator and director of the Center for Arrhythmia Prevention at Brigham and Women’s Hospital in Boston, says the results indicate there is no point in taking folic acid specifically for prevention of heart disease, but there are other reasons for women to take the vitamin, such as prevention of neural tube defects in the fetus during pregnancy.
“These data, along with previously published randomized trials, suggest that these supplements … are not effective as preventive agents against cardiovascular disease in those with established cardiovascular disease or those at high risk.”
The study involved 5,442 female health professionals at least 40 years of age who had pre-existing heart disease or at least three risk factors for the condition. They were randomly assigned in equal groups to inactive placebo pills or a daily combination of folic acid, vitamin B6 and vitamin B12.
Over an average of seven years, about 15 per cent of women in both the placebo and vitamin groups had a heart attack or stroke, died from heart disease, or needed a procedure to open a blocked artery. Outcomes were the same in both groups despite the fact the vitamins were effective at lowering homocysteine levels.
The study follows at least two other disappointing studies of B vitamins in heart disease. In 2005, investigators with the Norwegian Vitamin Trial told the European Society of Cardiology annual congress that folic acid and vitamin B6 dramatically reduced homocysteine levels in their study of more than 3,700 heart attack patients, but did not produce actual health benefits.
And in 2004, a study published in the Journal of the American Medical Association showed that folic acid, vitamin B6 and vitamin B12 failed to prevent repeat strokes in 3,680 adults.