Researchers at the Children's Memorial Research Center of Northwestern University in Chicago analyzed the results of eight previous studies on folic acid and stroke and found that folic acid sharply reduced the risk of stroke in adults.
Folic acid has been known to prevent neural birth defects in babies such as spina bifida, common childhood cancers like neuroblastoma, as well as heart malformations and cleft palate.
In the study, people who took folic acid supplements had their risk of stroke fall by about 18 % and those who took the supplements for an extended period of time, for over three years, had their risk fall by 29%.
These were just preliminary studies and so much is left to be done. Many questions are still unanswered, like the role of fortification of foods with folic acid, the optimal dose of folic acid, and the importance of other B vitamins in stroke prevention. It is still needed to determine whether folic acid, in combination with other B vitamins, would increase the risk of heart disease as previous research indicated.
Folic acid lowers the concentration of homocysteine, an amino acid, in the blood. High amounts of this amino acid are thought to damage the lining of arteries and aid to formation of clots which, in turn, increase the risk of stroke, heart attack and deep-vein thrombosis.
Researchers underline that more research is needed before making a conclusion whether continued use of folic acid supplements outweighs the risk of other adverse outcomes.