The following are excerpts from a vast study on alcohol and health, commissioned by Éduc'alcool and published in May 1997. Written by Hortense Fournier and Louise Nadeau of the University of Montreal, the document presents findings on extensive research into various aspects of the drinking-and-health issue. In some ways, it is the "mother of all studies" on the subject. Copies may be obtained from Éduc'alcool (1-888-ALCOOL1) or at the organization's website: www.educalcool.qc.ca

The principal benefit of regular, moderate drinking is reputedly to protect the heart through its potential antiatherogenic effect (prevention of clogged arteries). Atherosclerosis results from a build-up of fatty deposits and other cells on the arterial walls. As this "plaque" accumulates, the walls of the arteries thicken, reducing blood flow and the supply of oxygen and other nutrients to the body. So-called "hardening of the arteries" is the cause of many cardiovascular problems, the most common of which are coronary heart disease (angina) and myocardial infarction (heart attack).

The studies

The results of post-mortems to determine the degree of arterial blockage are mixed, but the majority of such studies indicate that alcohol has a protective effect.

Animal tests to determine the effects of alcohol on atherosclerosis show a protective effect in mice.

Countless epidemiological studies

Arterial diameter can be measured using arteriography, an X-ray process in which the arteries are injected with an opaque liquid. Arteriographic studies suggest that atherosclerosis progresses more slowly among heavy drinkers. Such data are quantitative and reliable.

Observational studies examine mortality statistics in relation to drinking habits. All these studies come to the same conclusion: there is a link between increased alcohol consumption and a drop in mortality due to coronary disease. These are the studies we've heard about most in the media. However, a number of methodological limitations are involved, and these findings must be corroborated by other studies, using different methodologies, before the results can be considered conclusive.

Case study research examines the various risk factors a group of people with coronary disease are exposed to, as compared to a disease-free control group. Studies show that regular, moderate drinkers appear to benefit from some sort of coronary protection, compared with those who do not drink at all. There is a very strong correlation between regular, moderate drinking and a lower incidence of heart disease.

In longitudinal studies, two or more groups of healthy individuals are chosen according to various criteria - drinking behaviour is one of them - and followed over the course of several years, during which they are monitored to see how drinking affects the development of coronary disease. Most such studies have shown that the incidence of heart disease is inversely proportionate to moderate drinking. Other studies have found no relationship, and some have shown alcohol to have a harmful effect, even in small quantities.

Despite such inconsistencies, the number of studies showing positive results tip the scales in favour of the beneficial effect of alcohol. Given the weight of evidence produced by these epidemiological studies, it would certainly appear that people who drink moderately are less likely to develop coronary disease, and especially less likely to die from it.