Establishing Alcohol as a Risk Factor for Burden of Disease

Dimensions of Alcohol Relevant for Burden of Disease and Social Harm. The relationship between alcohol consumption and health and social outcomes is complex and multidimensional. Figure 1 gives an overview. Alcohol consumption is linked to health and social consequences through three inter­mediate outcomes: direct biochemical effects, intoxica­tion, and dependence (Rehm et al., 2003a). An example of such direct biochemical effects is the promotion of blood clot dissolution or direct toxic effects on acinar cells trig­gering pancreatic damage.

Figure 1 shows only the main causal pathways thus indirect consequences were not included. For example, the model does not explicitly cover the situation in which a drunk driver kills somebody and, due to the emotional impact of this event on the drunk driver, he or she loses employment and becomes socially marginalized. In this example, the model covers the effects of alcohol on acute consequences (i.e., the driving accident), but does not explicitly cover the sub­sequent job loss and social marginalization.

Figure 1. Model of alcohol consumption, intermediate outcomes, and long-term consequences. Asterisk indicates independent of intoxication or dependence. Reproduced from Rehm J, Room R, Graham K, et al. (2003a) The relationship of average volume of alcohol consumption and patterns of drinking to burden of disease – an overview. Addiction 98: 1209–1228, with permission of Blackwell Publishing

Intoxication and dependence are, of course, also influ­enced by biochemistry. However, since these two interme­diate outcomes are central in shaping the effect of alcohol on many health and social outcomes, they are discussed separately. The other pathways are often specific for one disease or a limited group of diseases. Both intoxication and dependence are defined as health outcomes in the International Classification of Diseases (ICD-10).

Direct biochemical effects, intoxication, and alcohol dependence. Direct biochemical effects of alcohol may influence chronic disease either in a beneficial or harmful way. Beneficial effects include the influence of moderate drink­ing on coronary heart disease by way of effects on reduc­tion of plaque deposits in arteries, on protection against blood clot formation, and on promotion of blood clot dissolution. Examples of harmful effects include increas­ing the risk for high blood pressure and direct toxic effects on acinar cells triggering pancreatic damage or hormonal disturbances.

The label of direct toxic and beneficial effects is used to summarize all the biochemical effects of alcohol on body functions, which are independent of intoxication and dependence. In terms of the level of burden, special emphasis should be given to the hepato-toxic properties of some forms of alcohol, such as surro­gate alcohol in Russia and other countries in Central and Eastern Europe (McKee et al, 2005).

Intoxication is a powerful mediator mainly for acute outcomes, such as accidents, intentional injuries or deaths, and domestic conflict and violence, although intoxication episodes can also be implicated in chronic health and social problems. The effects of alcohol on the central nervous system mainly determine the subjective feeling of intoxication. These effects are felt and can be measured even at consumption levels that are light to moderate (Eckhardt et al, 1998).

Alcohol dependence is a disorder in itself, but is also a powerful mechanism sustaining alcohol consumption and mediating its impact on both chronic and acute physiolog­ical and social consequences of alcohol (Rehm etal., 2004).

This article is restricted to health consequences only. However, when analyzing the burden of disease linked to alcohol one should not overlook that in some regions and countries, the social harm related to alcohol is more important or costly than the health consequences.