Caffeine-containing beverages and the prevalence of hypertension.

Caffeine can produce a mild hypertensive effect for a few hours after use. Some epidemiological data relate chronic coffee intake to an increased risk of cardiovascular disease. We explored the possibility that a regular intake of caffeine-containing beverages (tea, coffee, cola) might produce a chronic increase in blood pressure and increase the likelihood of developing sustained hypertension. A random population survey of 2436 adults was made, with standardized blood pressure readings and a food-frequency questionnaire to determine the regular intake of various nutrients. We found evidence that caffeine intake was positively related to an increased diastolic blood pressure but the effect was small (less than 1 mmHg at usual caffeine intake). There was no evidence that a regular caffeine intake increases the risk of being classified as hypertensive.