Younger women who take more folic acid may have less of a chance of developing high blood pressure. While smaller studies have recommended that high-dose folic acid supplementation may lower blood pressure, there have been no larger studies examining the issue. The current study, reported in the Journal of the American Medical Association (January 18, 2005), examined data on 94,000 women aged 27 to 44 years enrolled in the Nurses'Health Study II. None of the participants had high blood pressure at the study's onset. The researchers based the participants'folate intake on food questionnaires and information regarding folate-containing supplements. In the 8 years of follow-up, 7373 of the women developed hypertension.
For the 2-part study, the researchers took into account physical activity, weight, and family history. The results of the study showed that women who consumed at least 1000 mcg per day of total folate had a 46% lower risk of becoming hypertensive, compared with the participants with an intake of <200 mcg per day.
The second phase of the study examined data on >62,000 older women (43 to 70 years of age) in the Nurses Health Study I. Of the participants, 12,347 developed high blood pressure. The chance of hypertension was reduced by 18% for the highest versus lowest folate intake. The researchers discovered that the benefit came primarily from folate supplementation rather than dietary folate.