Research results Health benefits overestimated by alcohol

Moderate alcohol consumption does not increase life expectancy
In the past, there have been many speculations about possible positive health effects with moderate alcohol consumption. Many people still believe that having a glass of wine a day makes them live longer and healthier lives. However, the scientific evidence available is "shaky at best", reports the journal "Journal of Studies on Alcohol and Drugs". The current issue of the journal features a comprehensive study by Canadian researchers from the Center for Addiction Research at the University of Victoria on the subject.

The researchers at the University of Victoria's Center for Addiction Research in British Columbia have used their extensive research to evaluate the results of 87 older studies to find out about the possible health benefits of alcohol consumption. Her conclusion, however, is sobering. Much of the study, which found benefits, was flawed and the results therefore unreliable. In the opinion of study author Tim Stockwell, there are many reasons to be skeptical about claims about supposed positive health effects of moderate alcohol consumption.

Moderate alcohol use has been associated with health benefits in numerous studies, but most of these studies show significant weaknesses. (Image: Igor Normann / fotolia.com)

Studies with significant weaknesses
Numerous positive effects of moderate alcohol consumption up to a significant extension of life expectancy were found in the evaluated studies, but on closer inspection the studies showed considerable weaknesses. Many were flawed and designed in the study design in such a way that advantages were found in places, where actually no advantages are to be found, the researchers report.

For example, the key questions in the research are how the "abstainers" were defined, and then compared to the group of moderate alcohol consumers, said Tim Stockwell, director of the Center for Addiction Research in British Columbia. For example, mostly moderate drinkers (up to two drinks per day) were compared to "current" teetotalers, but the group of teetotalers could include people in particularly poor health, for whom alcohol consumption was therefore excluded.

No causal connection given
If the group of abstainers was adjusted for persons with particularly high levels of health problems, the studies criticized showed no advantages of moderate alcohol consumption compared to abstinence, Stockwell and colleagues report. Only 13 out of the 87 studies had a disproportionately negative bias on the abstainers in their design and no health benefits of alcohol consumption were found in these studies, the researchers write. After adjusting the data used, it was also shown that people who consumed less than one drink a week had the highest life expectancy. In view of the extremely low alcohol intake and irregular consumption, however, no causal link can be assumed here.

Implausible benefits with moderate alcohol consumption described
In the present studies, moderate consumption of alcohol resulted in an implausible wide range of health benefits, says study author Stockwell. For example, moderate alcohol users have shown a lower risk of deafness or even cirrhosis of the liver than abstainers.

"Either alcohol is a panacea ... or moderate alcohol consumption is actually an indication of other factors," says Stockwell. Furthermore, according to the researchers, there were no effects on longevity with regard to the different types of alcoholic beverages. "But even if that were the case, it's unlikely that the alcohol content itself is the cause," says Stockwell. (Fp)