Compared with persons who abstain from drinking alcohol, persons who use alcohol regularly have higher death rates from suicide, certain cancers and cirrhosis. However, data also show that people who drink alcohol have lower rates of death from thrombotic stroke and ischemic heart disease. The reasons for this latter association are not clear. Thun and associates, as part of the Cancer Prevention Study II of the American Cancer Society, assessed the relationship between death rates from various causes and alcohol consumption in American adults.
Data were compiled for approximately 490,000 persons aged 30 years and older (mean age: 56 years). The study subjects were among the 1.2 million participants in the Cancer Prevention Study II, a prospective study that began in 1982. A four-page questionnaire was used to obtain information about alcohol and tobacco use, diet and other factors that may have a bearing on mortality. Alcohol consumption was quantified into five categories ranging from none to more than four drinks a day. The majority of participants were married, college graduates, middle-class and white.
An increase in the percentage of people who smoked paralleled an increase in alcohol consumption. Only 22 percent of the study subjects who had less than one drink per day were smokers, compared with 37 percent of those who had four or more drinks a day.
By 1991, a total of 46,000 deaths had occurred among the 490,000 participants. Alcohol consumption was associated with increased rates of death from cirrhosis, alcoholism and cancers of the mouth, esophagus, pharynx, larynx and liver combined. The rates of death were three to seven times higher among people who reported consuming four or more drinks a day. The mortality rate from external causes, such as suicide and accidents, was increased in men who consumed four or more drinks a day. The mortality rate from breast cancer was 30 percent higher in women who had at least one drink a day compared with women who did not drink alcohol.
With respect to death from cardiovascular disease, alcohol consumption was associated with a decreased mortality rate. Compared with abstainers, men and women who reported consuming at least one drink a day had a 30 to 40 percent lower mortality rate from all cardiovascular diseases combined. The rates of death from all causes were lowest among men and women who reported ingesting one alcoholic drink daily and were about 20 percent below those of nondrinkers. The risk of death from cardiovascular disease in smokers between 35 and 69 years of age was double that of nonsmokers.
The authors draw several conclusions from this study. First, persons who consume one or two drinks daily have a lower overall mortality rate than nondrinkers. Second, balancing the adverse effects of drinking with any beneficial effects on mortality depends on the amount of alcohol consumed as well as the person's age and risk of cardiac disease. Finally, alcohol consumption does not compensate for the significant increase in the risk of cardiovascular disease and death from cigarette smoking.