A randomized controlled trial of the effect of alcohol consumption on blood pressure.

Forty-six healthy normotensive male drinkers participated in a randomized, controlled, crossover trial to study the effects of varying alcohol intake on blood pressure. Alcohol consumption (calculated from weekly diaries) was reduced from 336.3 (s.e.m. = 20.2) to 64.5 (s.e.m. = 5.6) ml ethanol/week by drinking low alcohol content beer alone. Systolic blood pressure fell significantly during reduction of alcohol intake and rose again when normal drinking habits were resumed, the mean difference during the last 2 weeks of normal or low alcohol intake being 3.8 mmHg. This effect of alcohol on blood pressure was independent of a small but significant decrease in weight following reduction of alcohol intake. The change in blood pressure correlated with change in alcohol consumption (r = 0.53, P less than 0.001) with a 1 mmHg fall predicted for each 100 ml of reduction in ethanol intake/week. We conclude that regular moderate alcohol consumption has a direct (but reversible) pressor effect in normotensive men.