Focus On: The Cardiovascular System

Although heavy alcohol consumption has deleterious effects on heart health, moderate drinking is thought to have cardioprotective effects, reducing the risk of coronary artery disease and improving prognosis after a myocardial infarction. It still is unclear, however, if this effect can be achieved with all types of alcoholic beverages and results from the alcohol itself, from other compounds found in alcoholic beverages, or both. For example, the polyphenolic compound resveratrol, which is found particularly in red wine, can reduce the risk of atherosclerosis; however, it is not clear if the resveratrol levels present in wine are sufficient to achieve this result. Alcohol itself contributes to cardioprotection through several mechanisms. For example, it can improve the cholesterol profile, increasing the levels of "good" cholesterol and reducing the levels of "bad" cholesterol. Alcohol also may contribute to blood clot dissolution and may induce a phenomenon called pre-conditioning, whereby exposure to moderate alcohol levels (like short bouts of blood supply disruption [i.e., ischemia]), and result in reduced damage to the heart tissue after subsequent prolonged ischemia. Finally, the enzyme aldehyde dehydrogenase (ALDH) 2, which is involved in alcohol metabolism, also may contribute to alcohol-related cardioprotection by metabolizing other harmful aldehydes that could damage the heart muscle.