OBJECTIVE: To examine the effect of moderate coffee consumption on blood pressure over a prolonged period of time. Previous work in this area has used primarily purified caffeine. DESIGN: A prospective, randomized, crossover clinical trial. SETTING:A hypertension specialty outpatient clinic at the University of Tennessee, Memphis. PATIENTS: Healthy, young, white men who were moderate coffee drinkers (less than 6 cups/day) were recruited. Twenty-four subjects were randomized and 21 (average age 35.5 years) completed the trial. INTERVENTIONS: Subjects were randomized to one of two groups: Group A drank three or more cups of coffee/day for two months, then crossed over to abstaining from coffee for two months; group B abstained from coffee first, then crossed over to drinking coffee. Only filter-brewed coffee was used. Subjects were seen at monthly intervals for blood pressure measurements. MEASUREMENTS AND MAIN RESULTS: The average coffee consumption was 3.6 cups/day during the coffee-drinking phases. There was no difference between the coffee-drinking phase and the abstention phase in either systolic blood pressure (110.1 mmHg vs. 108.0 mmHg, respectively; 95% CI of difference -7.3, 2.5) or diastolic blood pressure (67.2 mmHg vs. 69.6 mmHg, respectively; 95% CI of difference -2.2, 6.4). CONCLUSIONS: Moderate daily consumption of coffee does not elevate blood pressure.
RCT Entities:
OBJECTIVE: To examine the effect of moderate coffee consumption on blood pressure over a prolonged period of time. Previous work in this area has used primarily purified caffeine. DESIGN: A prospective, randomized, crossover clinical trial. SETTING: A hypertension specialty outpatient clinic at the University of Tennessee, Memphis. PATIENTS: Healthy, young, white men who were moderate coffee drinkers (less than 6 cups/day) were recruited. Twenty-four subjects were randomized and 21 (average age 35.5 years) completed the trial. INTERVENTIONS: Subjects were randomized to one of two groups: Group A drank three or more cups of coffee/day for two months, then crossed over to abstaining from coffee for two months; group B abstained from coffee first, then crossed over to drinking coffee. Only filter-brewed coffee was used. Subjects were seen at monthly intervals for blood pressure measurements. MEASUREMENTS AND MAIN RESULTS: The average coffee consumption was 3.6 cups/day during the coffee-drinking phases. There was no difference between the coffee-drinking phase and the abstention phase in either systolic blood pressure (110.1 mmHg vs. 108.0 mmHg, respectively; 95% CI of difference -7.3, 2.5) or diastolic blood pressure (67.2 mmHg vs. 69.6 mmHg, respectively; 95% CI of difference -2.2, 6.4). CONCLUSIONS: Moderate daily consumption of coffee does not elevate blood pressure.
Authors: S Streufert; R Pogash; J Miller; D Gingrich; R Landis; L Lonardi; W Severs; J D Roache Journal: Psychopharmacology (Berl) Date: 1995-04 Impact factor: 4.530