Folic acid is a synthetic compound of folate, a B vitamin found in green leafy vegetables. The synthetic folic acid found in vitamins and fortified foods is easier to absorb than naturally occurring folate.
Folic acid has already been shown to cut the risk of birth defects, such as spina bifida, if taken during pregnancy.
In the new study, British researchers said it also helps to prevent heart disease, stroke and blood clots by assisting enzymes in the body to break down a substance in blood called homocysteine.
“Homocysteine is a cause of heart attack and stroke but we can reduce the risk of these diseases by taking more folic acid [supplements],” Dr. David Wald, a cardiologist at Southampton General Hospital who co-authored the study, told Reuters.
Wald and his colleagues, who analyzed the results of 72 earlier studies examining the link between homocysteine and heart disease, said the exact mechanisms of how it contributes to the disorders is still unknown, but it appears to injure the inner lining of arteries and increases the stickiness of blood.
“It is likely that homocysteine acts in more than just one way in damaging heart muscles and leads to blood clots forming in the arteries of the heart, brain and the legs and lungs,” he said in the report.
Wald and his colleagues estimate that a minimum increase of 0.8 milligrams of folic acid each day can cut heart disease risk by 16 percent, blood clots by 25 percent and stroke by 24 percent.
The United States started fortifying flour with folic acid in 1998 after its role was established in reducing birth defects. Wald said he believes this program will have a similar impact on heart disease and strokes.