BMJ paper urges caution on homocysteine

A meta-analysis published in the November issue of the British Medical Journal uges caution over folic acid supplementation as a way of reducing the risk of heart disease and strokes. Lead study author David Wald and his colleagues, noted that: "since folic acid reduces homocysteine concentrations [a risk factor for heart disease], to an extent dependent on background folate levels, it follows that increasing folic acid consumption will reduce the risk of heart attack and stroke by an amount related to the homocysteine reduction achieved. We therefore take the view that the evidence is now sufficient to justify action on lowering homocysteine concentrations."

The paper concludes that both cohort and genetic polymorphism studies show a similar association between decreased serum homocysteine and cardiovascular risk, even though they are subject to different error. Among genetic polymorphism studies, those with the greatest difference in homocysteine had the greatest difference in CV risk and, while randomized trials are consistent with a short-term protective effect, they lack the statistical power to be conclusive. According to Dr Ward, taken together the evidence supports a modest protective effect of folic acid.