High folate intake lowers women's blood pressure

Upping the daily intake of folate has been widely promoted in recent years to reduce women's risk of having a baby with spina bifida, but it also seems to have another benefit.

Women consuming 800 micrograms per day or more of folate are significantly less likely to develop high blood pressure than women consuming lesser amounts, according to a report presented Monday at the American Heart Association's annual conference on high blood pressure research in Chicago.

Dr. John P. Forman of Boston's Brigham and Women's Hospital reported the data from the Nurses' Health Study I, which included 62,260 women between 43 and 70 years old, and the Nurses' Health Study II, comprising 93,043 women between 26 and 46.

None of the women had high blood pressure when they were enrolled. They completed detailed questionnaires about their diet, food preparation and health habits, including folate intake, every 2 years for an average of 8 years. The women also self-reported their blood pressures.

"These were pretty detailed questionnaires," Forman told Reuters Health. "We calculated how much folate the women got from their diet and supplements. Our calculations were pretty accurate."

The investigators divided the women into five categories according to folate intake, the average being approximately 250 micrograms daily.

Younger women - those in the Nurses' Health Study II - who consumed 800 micrograms or more per day had a 29 percent lower risk of high blood pressure than those who consumed less than 200 micrograms daily. Older women in the highest category had a 13 percent lower risk of high blood pressure than those in the lowest category.

"It is very hard to get (800 micrograms folate daily) from diet alone," Forman noted. "Essentially all the women in the highest category took supplements."