Harvard Men's Health Watch

Adding folate to blood pressure medication reduces stroke

People with high blood pressure could benefit from a B vitamin known as folate if they are not getting enough from their diets, according to a study in The Journal of the American Medical Association (JAMA).

The study included more than 20,000 adults in China with high blood pressure who had never had a stroke or heart attack. Participants who took folate supplements along with a blood pressure medication had fewer strokes over the four-and-one-half-year trial than those who only took the medication.

Adding folate modestly reduced the absolute risk of first stroke, from 3.4% to 2.7%, a change of less than one percentage point. In those who started with the lowest folate intake, the effect was larger, or about two percentage points of difference.

It may be premature to give everyone with high blood pressure an extra daily bump of folate. In the United States, folate levels are already pretty high, thanks to artificial fortification of grain products with synthetic folate, known as folic acid.

High background folate levels may help explain why past studies have not found strong evidence that taking extra folate prevents heart attacks and strokes. It might have more impact in countries where folate intake is lower. Besides fortified grains, good sources of folate include green leafy vegetables, beans, peas, nuts, and citrus and other fruits.