Folic acid reduced risk for heart disease, stroke, and cut birth defects in children whose mothers had adequate levels of this essential nutrient.

     In a heart study, researchers recruited 46 men and women with coronary artery disease and high levels of homocysteine, a risk factor for the illness. Some participants also had a genetic defect (T-allele) that raises homocysteine. After eight weeks of taking 400 mcg of folic acid per day, or a placebo, those in the folic acid group had lower homocysteine levels, and homocysteine decreased most in those with T-allele.

     In a stroke study, researchers analyzed eight recent clinical trials and found that, compared to those who had not taken folic acid, those who had were 18% less likely—and those who had taken folic acid for more than 36 months were 29% less likely—to have a stroke. Researchers concluded that folic acid can prevent stroke.

     In a birth defect study, researchers in the New England Journal of Medicine tracked 1.9 million births in seven Canadian provinces for 10 years during which manufacturers began to fortify foods with folic acid. Scientists found that birth defects of the spine, nerves, and brain—together known as neural tube defects, or NTDs—decreased 46% from 1.58 NTDs per 1,000 births before folic acid-fortified foods to 0.86 afterward.

     In another birth defect study, researchers analyzed the diets of 1,336 mothers during the first three months of pregnancy and found that—compared to children whose mothers had less than 400 mcg of folic acid per day—children whose mothers had at least 400 mcg of folic acid per day were 39% less likely to be born with cleft lip, and 64% less likely when those mothers took folic acid, multivitamin supplements, and had a diet rich in folate, the food form of folic acid.

     Doctors believe that women can prevent up to 70% of NTDs by taking folic acid before and during early pregnancy, that folic acid is safe, and that most women do not get enough.

Reference: The Lancet: June, 2007; Vol. 369, No. 9576.