Folic acid may lower the risk of stroke

Researchers in the United States say folic acid supplements may reduce the risk of stroke by more than 18 percent.

The scientists at Northwestern University's Children's Memorial Hospital and Children's Memorial Research Center, Chicago, say folic acid lowers the concentrations of homocysteine in the blood which is thought to increase the risk of stroke, as well as that of cardiovascular disease and deep vein thrombosis.

Professor Xiaobin Wang and colleagues carried out a meta-analysis of eight trials of folic acid that had stroke reported as one of the endpoints.

The team found folic acid supplementation reduced the relative risk of stroke by an average of 18 per cent and an even greater reduction of risk was seen when the treatment lasted over 36 months (29% less risk).

The study also found that in areas that did not already have supplementation through fortified or partly fortified grain, folic acid supplementation decreased the risk of stroke by 25%.

But the scientists caution that there remains controversy as to whether folic acid supplementation can lead to improved outcomes for other cardiovascular conditions and say more clinical trials need to be done in regions without grain fortification, with a longer period of follow-up (4 years or longer), and among individuals without a history of stroke.

The report is published in the current issue of The Lancet.