A study* reported online on April 4, 2012 in the American Journal of Clinical Nutrition found that young adults who had a higher intake of folate had a significantly lower risk of developing high blood pressure over a 20 year follow-up period.
Pengchung Xun of the University of North Carolina at Chapel Hill and colleagues evaluated data from 4,400 African American and Caucasian men and women who were between the ages of 18 and 30 at the time of enrollment in the Coronary Artery Risk Development in Young Adults (CARDIA) Study in 1985. Dietary questionnaires were analyzed for total folate intake from dietary and supplemental sources at the beginning of the study and at follow-up visits during 1992 and 2005. Blood pressure was also assessed upon enrollment and again in 1987, 1990, 1992, 1995 and 2000. Serum folate levels were analyzed in a subset of participants.
The results? Men and women whose folate levels were among the top one-fifth of participants had a 52 percent lower incidence of hypertension compared to those whose intake was among the lowest fifth. When participants were examined by race, Caucasians who were among the top one-fifth of folate intake had a 67 percent lower risk and African Americans had a 46 percent lower risk of having high blood pressure in comparison with the lowest groups. Having a higher serum level of folate at baseline was also found to be protective, which helps confirm the conclusion drawn by the analysis.
While the precise mechanism behind this protective effect is not known, the study’s authors suggest improved endothelial (the thin layer of cells lining blood vessels) function as a possible mechanism for folate in helping to prevent hypertension. But the authors also indicate that further research is needed to clarify this hypothesis. "Our findings provide prospective evidence that a higher intake of folate is associated with a lower incidence of hypertension," they conclude. "This inverse association was more pronounced in whites than in African Americans. Further studies are warranted to establish causal inference."