Alcohol and Your Heart People Who Should Abstain From Alcohol According to the American Heart Association, there are a number of reasons certain people should not drink alcohol. These include: • A personal or strong family history of alcoholism • Uncontrolled high blood pressure • High blood triglyceride levels • Heart failure • Liver disease • Pancreatitis (inflammation of the pancreas) • Porphyria (a genetic disorder of metabolism) • Pregnancy • The use of medications that can have adverse interactions with alcohol   From The 2002 edition of the Johns Hopkins Coronary Heart Disease White Paper.  For a number of years, medical research has linked light to moderate alcohol consumption with numerous health benefits, including a lower risk of coronary heart disease (CHD). In fact, over 60 studies have found that people who consume one or two drinks per day have decreased rates of CHD. Nonetheless, the American Heart Association (AHA), while outlining the potential heart-healthy benefits of moderate alcohol consumption in the January 23, 2001, issue of the journal Circulation, does not endorse light drinking for the prevention of CHD. So just what does the scientific research say about alcohol’s effect on health, particularly on the heart, and why doesn’t the AHA recommend a drink a day for everyone? The Research Alcohol consumption is a difficult phenomenon to study. Drinking alcohol tends to be associated with other factors—including education, age, smoking, race, ethnic background, diet, and exercise habits—that can also affect rates of CHD. Furthermore, there is no randomized trial that assigns some people to drink no alcohol and others to drink moderately. Therefore, researchers must rely on correlational studies that can only suggest a relationship between alcohol consumption and lower CHD rates. Without a randomized trial, no one can be certain that alcohol is the cause of any observed effects. Researchers typically define a "drink" as 12 oz. of beer, 4 oz. of wine, or 1.5 oz. of 80 proof (40% alcohol) liquor. Each contains 0.5 oz. of pure alcohol. People who consume alcohol moderately (that is, one to two drinks per day) are less likely to die from any cause than nondrinkers, occasional drinkers, or heavy drinkers. Further, people who drink any amount of alcohol regularly are 20% to 40% less likely than nondrinkers to develop CHD. However, as alcohol consumption increases to an average of three drinks a day or more, the lower risk of CHD associated with drinking alcohol is offset by an increase in alcohol-related causes of death, including alcoholic cardiomyopathy (a weakening of the heart muscle), hemorrhagic (bleeding) stroke, cirrhosis of the liver, pancreatitis (inflammation of the pancreas), certain cancers, trauma (such as car accidents), suicide, and homicide. Heavy alcohol intake can also cause high blood pressure. How Alcohol Affects CHD Risk Investigators have found that France has about half as many deaths from CHD as the United States, even though both populations consume similar amounts of animal fat. This phenomenon, called the French paradox, has led some investigators to postulate that the high rate of red wine consumption in France helps to prevent CHD. Indeed, certain studies have indicated that moderate consumption of wine, particularly red wine, is more cardioprotective than drinking other alcoholic beverages. This finding has not been confirmed in other research, and factors associated with wine drinking may explain the association: Wine drinkers (as opposed to beer or liquor drinkers) tend to eat less fat, smoke less, exercise more, and drink mainly with meals. To explain the French paradox, some researchers have suggested that the antioxidant compounds in wine (and dark beers) may protect the heart. However, research has not shown that antioxidants have this effect. Further, the AHA points out that any potential benefits from the antioxidants in wine could also be obtained by drinking grape juice or eating fresh fruits and vegetables. Another possible explanation for alcohol’s beneficial effect is an increase in blood levels of high density lipoprotein cholesterol (HDL, or "good," cholesterol). HDL helps remove cholesterol from the walls of the arteries, and high HDL cholesterol levels are associated with a lower risk of CHD. Consumption of one to two drinks a day raises HDL cholesterol levels by about 12%. This increase is similar to that seen with exercise but is lower than the 20% increase achieved with niacin therapy. Researchers attribute about half of alcohol’s cardioprotective effects to increased HDL cholesterol levels. Alcohol might also protect against CHD-related deaths by inhibiting constriction of the coronary arteries, limiting clot formation and, possibly, improving survival after a heart attack. The Role of Genetics A study in the February 22, 2001, issue of The New England Journal of Medicine suggests that the presence of certain genes may help to predict who will derive heart benefits from moderate alcohol intake. An enzyme called alcohol dehydrogenase type 3 (ADH3) helps to control how fast alcohol is broken down in the body. The gene that controls this enzyme comes in two forms: gamma1 and gamma2. Every person inherits one gene from each parent and therefore has one of three genotypes: gamma1gamma1, gamma1gamma2, or gamma2gamma2. People who have the gamma1gamma1 genotype metabolize alcohol the fastest; those with the gamma2gamma2 genotype process alcohol the slowest. In the study of 1,166 men (age 40 to 84), those who consumed at least one drink a day had a 38% lower risk of heart attack than men who averaged one drink or fewer a week. However, men with the gamma2gamma2 genotype derived the greatest cardioprotective effect from moderate alcohol intake. Men who had the gamma2gamma2 genotype and drank moderately were 86% less likely to have a heart attack than men with the gamma1gamma1 genotype who drank less than one drink per week. Further, men with the gamma2gamma2 genotype who drank moderately had the highest HDL cholesterol levels of all the men studied. The study authors write that the slower rate of alcohol metabolism in men with the gamma2gamma2 genotype may give alcohol more time to exert its cardioprotective effects. According to the authors, the results indicate that it is the alcohol itself—and not any confounding factors—that protects the heart. Asians and possibly other ethnic groups tend to have a faster rate of alcohol metabolism that is controlled, in part, by the ADH3 gene. However, other than genetic testing, there is no reliable way to determine one’s ADH3 genotype. What To Do Because research has not yet established a causal relationship between moderate alcohol intake and a low CHD risk, the AHA and the National Institute on Alcohol Abuse and Alcoholism recommend that people who do not drink regularly should not start to drink alcohol as a protective strategy against CHD. Instead, the AHA recommends more carefully studied and perhaps safer methods of CHD prevention that include consuming a healthy diet, exercising, and controlling cholesterol, weight, and blood pressure. In addition, people who do consume alcohol and are not at risk for alcohol-related problems should consume no more than one or two drinks a day. The AHA and the American College of Cardiology both recommend that women not exceed one drink per day. Some studies have linked heavy alcohol intake with breast cancer in women. Even with moderate drinking, the decrease in CHD risk associated with alcohol consumption may be outweighed by alcohol’s potential risks, especially in older people. Older people who drink may be susceptible to adverse interactions between alcohol and their prescription medications. For example, the U.S. Food and Drug Administration warns against alcohol use by people who take aspirin regularly. Alcohol can also increase the risk of falls, car crashes, and hemorrhagic stroke, which are of particular concern for older people. From The 2002 edition of the Johns Hopkins Coronary Heart Disease White Paper.