The roles of alcohol in the epidemiology of cardiovascular diseases.

Alcohol, both alone and in concert with deficiencies or excesses of other substances, can produce cardiomyopathy. In addition, alcohol can directly affect the cardiac conduction system and produce arrhythmias. Alcohol also affects known risk factors for stroke and coronary heart disease (CHD). Alcohol increases blood pressure, which may lead to hypertension and thus increase the risk of stroke. HDL cholesterol, which is inversely related to CHD risk, increases with alcohol, and LDL cholesterol, which is positively related to CHD risk, may decrease with alcohol, a potentially dually protective effect. However, both case-control and population based studies indicate only moderate levels of consumption, defined as two drinks per day or less, may be of benefit. Preliminary data from the Lipid Research Clinics Follow-up Study suggest that the beneficial effect of moderate amounts of alcohol may be mediated in part by increased HDL cholesterol and in part by another factor, possibly reduced coagulation. Clinical and laboratory data, in addition to epidemiologic data, suggest alcohol intake above two drinks per day leads to excess cardiovascular disease (CVD), probably reflecting hypercoagulability as well as hypertension at higher levels of intake. Because alcohol can lead to excess morbidity and mortality from CVD as well as several other diseases and conditions, public health policy should continue to discourage the drinking of alcohol, especially non-moderate consumption.