Alcohol, blood pressure and hypertension.

In the last 30 years a large number of cross-sectional studies, a smaller number of prospective cohort studies and several intervention studies have addressed the alcohol-blood pressure relationship. Although a number of questions--such as the validity of measurement of alcohol intake, shape of the alcohol-blood pressure relationship, threshold dose for hypertension, and plausible pathophysiological mechanisms--have not yet been answered satisfactorily, it is clear that a causal association exists between chronic intake of > or = 30-60 g alcohol per day and blood pressure elevation in men and women. To call the alcohol-blood pressure relationship causal is justified because chance and, to a large degree, bias and confounding, have been ruled out as plausible explanations in most observational studies. More importantly, the intervention studies support the observational studies and show a remarkable consistency in demonstrating a potentially valuable decrease in blood pressure when heavy drinkers abstain or restrict their alcohol intake. From the different studies a rule of thumb can be derived: above 30 g of alcohol intake per day an increment of 10 g of alcohol per day increases on average systolic blood pressure by 1-2 mmHg and diastolic blood pressure by 1 mmHg.