MONDAY, Oct. 11 , 2004 (HealthDayNews) -- Folate, a vitamin already known for its power to prevent birth defects, also appears to reduce the risk of high blood pressure for women both young and old.
New research shows that young women who consumed more than 800 micrograms of folate a day -- about the amount found in two multivitamins -- reduced their risk of developing high blood pressure by nearly a third compared to those who had less than 200 micrograms a day.
Folate also reduced the risk of high blood pressure in older women, but to a lesser degree, the study found.
The study was authored by Dr. John P. Forman, a research and clinical fellow at Brigham and Women's Hospital in Boston. It was presented Oct. 11 at the American Heart Association's annual high blood pressure research conference in Chicago.
"Two small studies before ours found a positive association between folate intake and blood pressure reduction," Forman said, although the women in those studies already had high blood pressure.
"As far as I know, this is the first study to look at a group of women who did not have a diagnosis of high blood pressure at baseline and look to see who got hypertension," he added.
The study isn't proof-positive that high folate intake prevents high blood pressure, he emphasized, and more studies will be needed to confirm the finding.
In this study, Forman's group evaluated 150,000 women, following them over eight years. One group included 62,260 women from the Nurses' Health Study I, aged 43 to 70. The other included 93,034 women from the Nurses' Health Study II, aged 26 to 46.
The women answered questions about their food intake at the start and then every four years. They reported any physician-diagnosed high blood pressure every two years during the eight-year follow-up period.
Among the younger women who took in more than 800 micrograms of folate a day, there was a 29 percent reduction in risk in high blood pressure, compared to those who consumed less than 200 micrograms a day. Older women who took in more than 800 micrograms daily had a 13 percent reduction in risk compared to those who took in less than 200 micrograms.
There also was a somewhat decreased risk in those who took in 400 to 600 micrograms, compared to those who took in under 200, but the risk reduction wasn't statistically significant, Forman said.
"Folate has been shown to reduce levels of homocysteine, a circulating compound in blood," Forman said. "Higher levels of homocysteine have been associated with cardiovascular disease." If the levels are too high, the production of nitric oxide, which relaxes blood vessels, drops, he explained.
Folate is a B vitamin that is found naturally in leafy green vegetables such as spinach and turnip greens, fruits, dried beans and peas. To consume 800 micrograms a day, you would need to take a multivitamin plus eat three-quarters of a cup of breakfast cereal fortified with 400 micrograms of folate, or other foods. A half cup of spinach, for instance, has 100 micrograms, and three ounces of beef liver has 185 micrograms.
Dr. Alice Lichtenstein, Gershoff Professor of Nutrition Science and Policy at Tufts University, called the report "interesting." But she cautioned that "the findings are associations only."
And no one should suggest at this point that people start relying on folate to decrease their blood pressure, she added.
More information
To learn more about folate, visit the National Institutes of Health Office of Dietary Supplements.
