B-vitamin supplements should not be recommended for prevention of heart disease, say scientists. A Cochrane Systematic Review has shown these supplements do not reduce the risk of developing or dying from the disease.
"There is no evidence to support the use of B-vitamins as supplements for reducing the risk of heart attack, stroke or death associated with cardiovascular disease," says lead researcher, Arturo Martí-Carvajal of the Iberoamerican Cochrane Network in Valencia, Venezuela. "And it is important to point out that although we may have not found a positive effect, these kinds of studies are vitally important for determining the factors that influence the risk of developing and dying from this disease, which is the number one cause of death in the world today."
Certain B-vitamins, specifically B12, B9 (folic acid) and B6, influence levels of an amino acid in the blood called homocysteine. High levels of this molecule are associated with an increased risk of heart disease. It has been suggested that giving B-vitamin supplements could help regulate levels of homocysteine, thereby reducing the risk of cardiovascular disease and death. But according to the researchers, there is no scientific basis for this claim.
The review included eight trials involving a total of 24,210 people. None of the eight trials individually supported the idea that giving B-vitamin supplements could prevent cardiovascular disease. Together the data show that B-vitamin supplements, whether compared with placebos or standard care, have no effect on the incidence of heart attack, stroke or death associated with heart disease.
"Prescription of these supplements cannot be justified, unless new evidence from large high quality trials alters our conclusions. There are currently three ongoing trials that will help to consolidate or challenge these findings," says Martí-Carvajal.