Several previous studies have indicated a possible association between caffeine intake and the risk of hypertension. Short-term studies have demonstrated that caffeine intake acutely increases blood pressure, but over time, weakening of this effect does occur. A long-term effect of caffeine intake on the risk of developing hypertension would be of substantial public health importance given the widespread consumption of beverages containing caffeine, but currently, studies of this association are scarce.
Wolfgang C. Winkelmayer, M.D., Sc.D., of the Harvard School of Public Health, Boston, and colleagues conducted a study to determine whether caffeine intake or consumption of certain caffeine-containing beverages is associated with an increased risk of incident hypertension in women. The researchers analyzed data from the Nurses’ Health Studies (NHSs) I and II of 155,594 U.S. women free from physician-diagnosed hypertension, who were followed-up over 12 years (1990-1991 to 2002-2003). Caffeine intake and possible confounders were ascertained from regularly administered questionnaires.
Over the 12 years, 19,541 incident cases of physician-diagnosed hypertension were reported in NHS I and 13,536 in NHS II. In both cohorts, no linear association between caffeine consumption and risk of incident hypertension was observed after multivariate adjustment. When studying individual classes of caffeinated beverages, habitual coffee consumption was not associated with increased risk of hypertension. By contrast, consumption of cola beverages was associated with an increased risk of hypertension, independent of whether it was sugared or diet cola.
MEDICA.de; Source: American Medical Association (AMA)