Effects of alcohol consumption on health and mortality

Abstract

During the last 25 years, alcohol consumption has become a widely debated issue, especially due to research results, in which the beneficial effects of alcohol on health and mortality have been maintained. Research has primarily focused on two issues: the association between low consumption of alcohol and decreased mortality, mediated through decreased risks for cardiovascular diseases, and the association between wine consumption and health. This thesis deals with both of these issues, as well as the identification of high and low consumers of alcohol, by means of a questionnaire and a health examination. The differential effects of high and low alcohol consumption, as well as the differential effects of diverse alcohol beverages are investigated, using data from National Cause of Death Register, National In-Patient Register and National Cancer Register. Multivariate analysis has been conducted to investigate the effects of alcohol and the influence of confounders. The plausibility of tracing high and low consumers of alcohol, through the use of two questions about alcohol consumption included in a questionnaire has also been investigated. The effects of a single health examination, seen in relation to morbidity and mortality, traced in the proceeding 22-year period have also be studied.

Among the results for 32,185 individuals the discrepancies found between men and women with high and low alcohol consumption are notable. An increased risk ratio was found for cardiovascular morbidity and mortality among men with high alcohol consumption, while for men with low alcohol consumption an increased risk ratio for mortality was found, but no increased risk ratio for morbidity. For women with low alcohol consumption, an increased risk ratio for morbidity and mortality was found. Such an association was not found for women with high alcohol consumption. Moreover, mortality was investigated among 1,828 individuals in relation to the amount and type of alcoholic beverage consumed. Those who consumed wine had a reduced total and cardiovascular mortality, compared to non-drinkers and those who consumed beer or liquor. Risk reduction seems to be confined to those consumers of wine, whose intake was less than 140 grams of alcohol per week and who consumed wine only once a week.

Furthermore, ex-drinkers were found to have an increased total and cardiovascular mortality. Self-reported health status was also investigated among 14,950 individuals, as it relates to the amount and type of alcoholic beverage consumed. Those individuals who consumed wine had better self-reported health status than individuals who consumed other types of beverages. Adjustments for confounders, such as smoking, exercise and different psychosocial factors, did not change the results.

The conclusions are drawn that individuals, who formerly have had high consumption of alcohol, but who have reduced their consumption, due to illness, are included in the group classified at the time of the study as low consumers, may serve as an explanation for the findings with low consumers. It is unclear as to which mechanisms are responsible for the observed differences between men and women as regards high alcohol consumption. Moderate consumption of wine has beneficial effects on self-reported health status, when compared to consumption of beer and liquor, and is associated with 50% reduction of risk for cardiovascular mortality. The beneficial effects of wine may be explained by the health promotional ingredients in wine and/or lifestyle factors, associated with wine consumption.

Further research is needed to investigate the effects of the ingredients in wine and life style factors on health and mortality. Although identification of high and low consumers, by means of the inclusion of two questions in a questionnaire, was shown to be effective, the results of health screening proved to be less positive. These studies nevertheless indicate that other measures, such as health screening for specific risk groups, might prove to be effective, as regards disease prevention.