Alcohol and cardiovascular health: Recent findings

This review is focused on recent studies published since 1997 that have contributed toward our current thinking about the association between alcohol consumption and cardiovascular disease. Recent studies reinforce the consistent finding of a J-shaped inverse association between alcohol and cardiovascular disease morbidity and mortality, primarily due to an underlying association between alcohol and coronary heart disease (CHD). Despite the methodological difficulties of studying alcohol consumption, epidemiological studies are surprisingly consistent in showing that light to moderate alcohol intake has an inverse association with the risk of cardiovascular disease morbidity and mortality compared with those who do not drink at all. The depth and width of the J-shaped inverse association is largely dependent upon the underlying lowered risk of CHD. Alcohol likely reduces the risk of cardiovascular disease through increases in plasma high density lipoprotein-cholesterol (HDL-C) levels. Further support for the HDL-C hypothesis comes from the lack of a differential effect of alcohol by beverage type, suggesting that ethanol is responsible for the protective effect. While other mechanisms for a reduced risk of cardiovascular disease by alcohol have been suggested - including hemostatic markers and improvements and insulin sensitivity - evidence remains preliminary. The current recommendation set forth by the American Heart Association and other groups to limit alcohol intake to no more than 2 drinks per day for men and 1 drink per day for women appear justified but must be cautiously promoted. Although the association of alcohol and cardiovascular disease is likely to be causal, these recommendations must consider the complexity of the metabolic, physiological, and psychological effects of alcohol. In general, maximal benefits and safety appear to be at the level of approximately 1 drink per day. Limited data suggest that the level for optimal benefit and safety may be slightly lower for women. From a public policy standpoint, whether the benefits for cardiovascular disease persist at heavier drinking levels or are attenuated, may not be relevant since clear harm in terms of overall mortality would likely outweigh any benefits in the reduction of cardiovascular disease.