Indication: Blood pressure

Source: American Heart Association’s 58th Annual High Blood Pressure Research Conference

Research: Data was collected from more than 150,000 women from two large studies—the Nurse’s Health Study I (NHS I), which includes 62,260 women, ages 43-70, and the Nurses’ Health Study II (NHS II), which includes 90,034 women, ages 26-46 (without a history of high blood pressure)—to determine if there was a link between the level of folate intake, including dietary supplements, and the risk of high blood pressure. The study participants were interviewed using a semi-quantitative food frequency questionnaire with questions about dietary and supplemental folate intake at baseline, then administered the same questionnaire every four years. Information about physician-diagnosed high blood pressure was self-reported on health status questionnaires every two years during the eight-year follow-up.

Results: The results showed the most dramatic effects among the younger group (NHS II), although folate benefited older women (NHS I) to a lesser extent. Younger women in the highest folate intake quintile (consuming more than 800 mcg/d) of total folate (from dietary intake plus supplements) had a 29% lower risk for high blood pressure than those in the lowest quintile (consuming less than 200 mcg/d of folate). Older women who had total folate intake of 800 mcg/d had a 13% lower risk. The results were independent of other factors, including exercise, salt intake and diet, which are known to influence body mass index (BMI); smoking; family history of hypertension; calcium, magnesium and potassium intake; fiber intake; methionine intake; caffeine and alcohol consumption; and use of vitamins B6, B12 and D. Researchers also looked at the independent effect of supplemental folic acid. Women in NHS II who consumed 800 mcg/d or more of folate mainly as supplemental folic acid had a 48% reduction in hypertension risk compared to those whose folate intake was less than 200 mcg/d (and who did not take supplements). Women in NHS I experienced a 40% reduction.