Epidemiologic evidence for the cardioprotective effects associated with consumption of alcoholic beverages

The impact of alcohol intake on mortality from all causes has been described in a large number of prospective population studies from many countries. Most have shown a J-shaped relation between alcohol intake and subsequent mortality, indicating that there are both beneficial and harmful effects of ethanol on health. The risk of death from ischemic heart disease is seen to be significantly increased, and highest among abstainers, but not significantly increased among heavy drinkers. Some studies have found plausible mechanisms for the beneficial effect of light to moderate drinking. Subjects with a moderate alcohol intake have a higher level of high density lipoprotein than abstainers. Further, moderate drinkers are seen to have a lower low density lipoprotein. Also, alcohol has a beneficial effect on platelet aggregation, and thrombin level in blood is higher among drinkers than among non-drinkers. In the other end of the range of intake, the ascending leg of the U-shaped curve has been explained by the increased risk of cirrhosis, pancreatitis, and development oropharynx, oesophagus, and breast cancer. In exploring the French paradox, it has been suggested that wine may have beneficial effects additional to that of ethanol. Recently, several prospective population studies have supported this idea. It is, however, also likely that the apparent additional beneficial effect of wine on health in addition to the effect of ethanol itself is a consequence of confounding.