Everything in moderation - the smart thing to do By Dr. Erik Skovenborg

Danish epidemiological studies of beverage choice and health have revealed many apparent health benefits related to moderate consumption of wine: lower risk for stroke, upper digestive tract cancer, lung cancer and hip fracture, and, most important, a lower rate of all-cause mortality as compared with abstaining, or beer or liquor drinking (1). However, the Danish studies based their analysis of the beneficial health effects of wine on observational data collected between 1976 and 1982. Before joining the European Community in 1973 Denmark was traditionally a beer-drinking community. In the seventies only a small proportion of the Danish population regularly drank wine.

During the seventies and eighties a dynamic change of drinking habits and beverage choice took place. Per capita consumption of wine rose from 5.91 litres in 1970 to 21.31 litres in 1990 = a 260% rise in wine consumption. In the same period the increase of per capita consumption of absolute alcohol from 6.82 litres in 1970 to 9.75 litres in 1990 amounts to a rise of only 42% in total alcohol consumption (2).

The principal reason for the increase of wine consumption in Denmark was exposure to wine through increased tourism to southern wine-drinking countries. As well, with Denmark's entry into the European Common market at the beginning of 1973, there was a reduction in the tax of wine. An analysis of changes in Finnish drinking habits and beverage preferences from 1984 to 1992 showed that for wine, the interest in the new beverage was stronger among the élites (3). In Denmark an analysis of smoking habits based on data from cross sectional WHO MONICA surveys conducted in 1982-92 showed a decrease of the prevalence of smoking during the study, but only in the most educated groups (4). The changes in smoking behaviour corresponded to a hierarchical diffusion model, non-smoking being first adopted among the higher social classes, with the lower social classes following after a time lag of usually 5-10 years. A recent analysis of trends in alcohol drinking in the Danish MONICA population 1982-92 found a decrease of alcohol consumption that was only significant among the highest educated. For example, in the highest educated men the prevalence of moderate alcohol use increased from 77 to 82% while heavy alcohol use declined from 19% to 12% (5).

The Danish wine drinkers from the seventies may thus represent a higher educated élite, and this raises the question as to whether the apparent health benefits of wine reflected the direct physiological effects of this beverage or other health-related individual differences between wine drinkers and non-wine drinkers. Morten Grønbæk and his colleagues recognize that the decrease in all-cause mortality in wine-drinkers may be confounded by genetic, psycho-social, or lifestyle-related factors (1). In their study 67% of non-wine drinkers and 54% of wine drinkers were current smokers. In addition, a larger proportion of wine drinkers were of higher social class, as indicated by educational level. The Danish scientists carefully controlled for these two factors in all analyses. Apparently drinking patterns was not a strong confounder. In the cohort from the Copenhagen Male study, only minor differences were observed in drinking patterns among wine, beer and spirits drinkers. However, no data on participants dietary habits were available. Wine intake in Denmark may be associated with consumption of a presumably healthy Mediterranean diet (6). In Italy wine drinking on the other hand do not show an association with indicators of healthy diet (7). And in Italy higher risks of oesophageal cancer were observed for wine-only drinkers. (8).

In the 1990's it has become much more common for Danes to drink wine, and, according to the hierarchical diffusion model, intellectual, social, and personality differences between wine drinkers and non-wine drinkers may be far less pronounced than in the 1970 population study by Morten Grønbæk and colleagues (9). To study the modern Danish wine drinkers Erik L. Mortensen and his colleagues examined the association between beverage choice and a broad spectrum of social, cognitive, and personality characteristics in a large sample of Danish adults evaluated between November 1990 and October 1994 (10).

Much to their surprise the Danish epidemiologists found wine drinking significantly associated with higher IQ, higher parental educational level, and higher socio-economic status. On scales concerning personality, psychiatric symptoms, and health-related behaviours, wine drinking was associated with optimal functioning and beer drinking with suboptimal functioning. The Danish experts do not offer any explanation of the phenomenon, nor do they try to sort out cause and effect. However, social status gradients in health are one of the most consistent findings of public health epidemiology. Consequently, the association between drinking habits and social and psychological characteristics, in large part, may explain the apparent additional health benefits of wine.

In conclusion, let me suggest that you enjoy your pint of bitter, your glass of cabernet or your tumbler of brandy - though in moderation. Its the smart thing to do.

Erik Skovenborg is a Medical Practitioner, founder member of the Scandanavian Medical Alcohol Board and a member of the AIM Editorial Board

References 1.Grønbæk M et al. Type of alcohol consumed and mortality from all causes, coronary heart disease, and cancer. Ann Intern Med 2000;133:411-19. 2.Produktschap voor Gedistilleerde Dranken, World Drink Trends, 1992 Edition. Oxfordshire: NTC Publications Ltd., 1992. 3.Simpura J et al. New beverages, new drinking contexts? Signs of modernization in Finnish drinking habits from 1984 to 1992, compared with trends in the European Community. Addiction 1995;90:673-83. 4.Osler M et al. Socioeconomic status and trends in risk factors for cardiovascular diseases in the Danish MONICA population, 1982-1992. J Epidemiol Community Health 2000;54:108-13. 5.Osler M et al. Socioeconomic status and trends in alcohol drinking in the Danish MONICA population, 1982-92. Scand J Public Health 2001;29:40-43. 6.Tjønneland A et al. Wine intake and diet in a random sample of 48763 Danish men and women. Am J Clin Nutr 1999;69:49-54. 7.Chatenoud L et al. Wine drinking and diet in Italy. Eur J Clin Nutr 2000;54:177-79. 8.Bosetti C et al. Wine and other types of alcoholic beverages and the risk of oesophageal cancer. Eur J Clin Nutr 2000;54:918-20. 9.Grønbæk M et al. Mortality associated with moderate intakes of wine, beer, or spirits. BMJ 1995;310:1165-69.10.Mortensen EL et al. Better psychological functioning and higher social status may largely explain the apparent health benefits of wine. Arch Intern Med 2001;161:1844-48.