Research on how tobacco and alcohol use interact to influence risk for cardiovascular disease is limited. Alcohol consumption of three or more drinks per day and cigarette smoking share similar, and probably additive, effects on some forms of cardiovascular disease. There is relatively little evidence, however, that the effects are worse when smoking and drinking occur together than would be expected from their independent effects. In most cases, moderate drinking does not share these risks and even has opposite effects of cigarette smoking on some risk factors. Ongoing public health efforts to minimize tobacco use and harmful drinking should result in clear and important gains to the nation's cardiovascular well-being. KEY WORDS: Alcohol and tobacco; alcohol and other drug (AOD) consumption; smoking; tobacco in any form; comorbidity; risk factors; beneficial moderate alcohol consumption; risk and protective factors; cardiovascular disorder; stroke; coronary artery disorder; congestive heart failure; high blood pressure; hypertension; cholesterol; alcoholic cardiomyopathy
An extraordinary body of research has sought to understand the links between smoking cigarettes and drinking alcohol, and an equally substantial body of evidence has demonstrated their synergy in causing cancer, birth defects, and other medical problems. In contrast, there generally has been little evidence that they interact to influence cardiovascular disease. Indeed, one recent review found only a single article that identified a probable interaction between alcohol and tobacco on risk of heart disease resulting from narrowing of the arteries that supply blood and oxygen to the heart (i.e., coronary heart disease) (Taylor and Rehm 2006). This article seeks to examine more broadly the ways that tobacco and alcohol may jointly affect risk of cardiovascular disease.
A COMPLICATED ISSUE
Several factors complicate the interactions between tobacco and alcohol on cardiovascular disease. First, dose matters. The relationship between smoking and risk of cardiovascular disease is dose dependent-more tobacco leads to more disease. For alcohol consumption, however, the issue is more complex. Most evidence suggests that consumption in the range of 3 to 14 drinks per week is associated with lower risk of heart attack (i.e., myocardial infarction) and possibly of other forms of cardiovascular disease, such as blockage in an artery that supplies blood to the brain, resulting in a deficiency in blood flow (i.e., ischemic stroke) or failure of the heart to pump blood sufficiently throughout the body (i.e., congestive heart failure). However, intake of three or more drinks per day clearly increases the risk of ischemic stroke, and heavier drinking may well increase the risk of myocardial infarction.
Second, cardiovascular disease encompasses a variety of conditions with a diverse set of causes or origins. Smoking is clearly linked to a higher risk of nearly all forms of cardiovascular disease, including myocardial infarction, ischemic stroke and bleeding into the brain (i.e., hemorrhagic stroke), congestive heart failure, and narrowing of the arteries in the extremities (i.e., peripheral arterial disease) (Burns 2003). The relationship between alcohol use and cardiovascular risk factors is not so clear. Moderate drinking has been associated with a consistently lower risk of myocardial infarction, but only a modestly lower risk of ischemic stroke, and a higher risk of hemorrhagic stroke. Simply combining all of these conditions together as "cardiovascular disease" will tend to blur these distinctions.
Third, even those types of cardiovascular disease directly linked to the gradual build-up of fatty deposits (i.e., plaques) in the arteries, such as myocardial infarction and stroke, represent acute events superimposed on the background process of the gradual narrowing and hardening of the arteries (i.e., atherosclerosis). Atherosclerosis itself is dynamic and involves cholesterol transport into and out of cells in the blood vessel wall, the entry of inflammatory cells, and abnormal function of the cells lining the vessel surface (i. …