British Stroke Association

On November 25, 2006 edition of the British Medical Journal published the conclusion of researchers at London's Queen Mary School of Medicine and the dentistry there is enough scientific evidence to justify the use of B vitamin folic acid as a simple and inexpensive method of reducing heart disease and stroke. A higher intake of folic acid is associated with lower levels of homocysteine, an amino acid linked to the development of cardiovascular disease.

Dr. David S. Wald and colleagues evaluated 27 cohort studies that examined the association between homocysteine levels and risk of heart attack and stroke in a large number of people, 80 studies that evaluated the effect of a genetic variant which increases homocysteine levels on heart disease and 30 who examined its effects on stroke, and 11 randomized controlled trials that examined the effect of lowering homocysteine on heart attacks and stroke.

Cohort studies analyzed and confirmed a significant positive association between high levels of homocysteine and heart attack and sudden cardiac death and stroke. A reduction of 3 micromoles per liter serum homocysteine, which can be achieved with 800 micrograms of folic acid per day was associated with a lower risk of 15 per cent of heart attack and a reduction of 24 percent of stroke . The analysis of genetic studies have provided similar results. Although randomized trials were too small to provide conclusive results, the results are consistent with small decreases in heart disease and ischemic stroke associated with the reduction of homocysteine.

"Since folic acid reduces homocysteine concentrations, a measure levels of folate-dependent background, it follows that increasing folic acid consumption reduces the risk of heart attack and stroke by an amount related to the homocysteine reduction achieved, "the authors conclude." We therefore take the view that the evidence is now sufficient to justify action on reducing homocysteine concentrations, although the situation should be considered as evidence of ongoing clinical trials appears.