The homocysteine hypothesis of heart disease has been put to the test–and it flunked. The trial was carried out with 12,000 British people who had survived their first heart attack. They were randomly assigned to take either dummy pills or vitamin B12 and folic acid to lower homocysteine. Homocysteine is an amino acid that is a breakdown product of protein metabolism. In past studies, high levels of homocysteine have been linked to a higher risk of heart disease. The researchers cite a recent meta-analysis showing that a 25 percent drop in homocysteine is linked to an 11 percent lower risk of heart disease. But taking the vitamins for about 7 years did not have any effect on the risk of heart disease or stroke. Homocysteine levels were reduced by about 25 percent, so this large careful trial demonstrates that taking B vitamins to lower homocysteine won’t help the heart.
[Journal of the American Medical Association, June 23/30, 2010]
The People's Perspective on Medicine