Alcohol and cardiovascular disease

The subject of alcohol and heart attacks is important because the major cause of death in many countries is heart disease.

Research indicates that moderate drinkers are less likely to suffer heart attacks than are abstainers or heavy drinkers (Anani et al.; Gaziano et al.; Manson et al.; Mulcamel et al.; National Institute on Alcohol Abuse and Alcoholism; Rimm et al.; Sesso et al.; Simons et al.; Walsh et al.). The first scientific study of the relationship between alcohol consumption and atherosclerosis was published in the Journal of the American Medical Association in 1904. Public awareness of the French Paradox in the early 1990s stimulated increased interest in the subject of alcohol and heart disease.

An exhaustive review of all major heart disease studies has found that "alcohol consumption is related to total mortality in a U-shaped manner, where moderate consumers have a reduced total mortality compared with total non-consumers and heavy consumers" (La Porte et al.). Research also reports that  the risk of a heart attack among moderate drinkers with diabetes is 52 percent lower than among nondrinkers and that the risk of dying in the four years after a heart attack is 32 percent lower among those who were moderate drinkers in the year before the attack (Beulens et al.).

Ex-drinkers versus never-drinkers
A logical possibility is that some of the alcohol abstainers in research studies previously drank excessively and had undermined their health, thus explaining their high levels of risk. To test this hypothesis, some studies have excluded all but those who had avoided alcohol for their entire lives. The conclusion remained the same in some studies: moderate drinkers are less likely to suffer heart disease.[3] Women who regularly consume an alcoholic drink or two have a significantly lower risk of having a non-fatal heart attack than women who are life-time abstainers and the benefits are greatest in women who drink daily, report medical researchers at the State University of New York’s University at Buffalo.

An analysis by sociologist Kaye Fillmore et al. failed to find significant support. Analyzing 54 prospective studies, the authors found that those studies which were free of the potential error (including former drinkers in the abstaining group) did not demonstrate significant cardiac protection from alcohol, although they continued to exhibit a J-shaped relationship in which moderate drinkers were less likely (but not at a statistically significantly level of confidence) to suffer cardiac disease than lifelong abstainers. The instructor of nursing says research is needed that looks at the reasons people abstain, which hers did not do.

Cardiologist Dr. Arthur Klatsky notes that Fillmore’s study, which she freely acknowledges proves nothing but only raises questions, is itself seriously flawed. To overcome the inherent weaknesses of all epidemiological studies, even when properly conducted, he calls for a randomized trial in which some subjects are assigned to abstain while others are assigned to drink alcohol in moderation and the health of all is monitored for a period of years.

Other Factors
Another possibility is that moderate drinkers have more healthful lifestyles (making them healthier), higher economic status (giving them greater access to better foods or better healthcare), higher educational levels (causing them to be more aware of disease symptoms), etc. However, when these and other factors are considered, the conclusion again remains the same: moderate drinkers are less likely to suffer heart disease.

Possible mechanisms of benefits
Given the epidemiological evidence that moderate drinking reduces heart disease, it becomes important to examine how alcohol might confer its cardiovascular benefits. Can alcohol’s protective affects be explained physiologically? Research suggests that moderate consumption of alcohol improves cardiovascular health in a number of ways     (Facchini et al), including the following.

I. Alcohol improves blood lipid profile. A. It increases HDL ("good") cholesterol. B. It decreases LDL ("bad") cholesterol. C. It improves cholesterol (both HDL and LDL) particle size (Mukamal, K. J. et al. Alcohol consumption and lippoprotein subclasses in older adults. Journal of Clinical Endocrinology & Metabolism, 2007, April. PMID: 17440017)

II. Alcohol decreases thrombosis (blood clotting). A. It reduces platelet aggregation. B. It reduces fibrinogen (a blood clotter). C. It increases fibrinolysis (the process by which clots dissolve).

III. Alcohol acts through additional ways. A. It reduces coronary artery spasm in response to stress. B. It increases coronary blood flow. C. It reduces blood pressure. D. It reduces blood insulin level. E. It increases estrogen levels

There is a lack of medical consensus about whether moderate consumption of beer, wine, or distilled spirits has a stronger association with heart disease. Studies suggest that each is effective, with none having a clear advantage. Most researchers now believe that the most important ingredient is the alcohol itself (Barefoot et al.).

The American Heart Association has reported that "More than a dozen prospective studies have demonstrated a consistent, strong, dose-response relation between increasing alcohol consumption and decreasing incidence of CHD (coronary heart disease). The data are similar in men and women in a number of different geographic and ethnic groups. Consumption of one or two drinks per day is associated with a reduction in risk of approximately 30% to 50%".

Heart disease is the largest cause of mortality in the United States and many other countries. Therefore, some physicians have suggested that patients be informed of the potential health benefits of drinking alcohol in moderation, especially if they abstain and alcohol is not contraindicated. Others, however, argue against the practice in fear that it might lead to heavy or abusive alcohol consumption. Heavy drinking is associated with a number of health and safety problems.