News

Don't uncork that Chateau Mouton Rothschild 1987 Bordeaux and raise a glass to your good health quite yet.

Much of the research demonstrating that moderate drinking helps prevent heart disease -- and that health-conscious baby boomers have so heartily embraced -- is fundamentally flawed, according to a new international study.

The problem is that almost all the studies lump together life-long abstainers with non-drinkers, who are generally drinkers who quit for health reasons or because of alcoholism.

As a result of this "systematic classification error," the people who did not drink were routinely shown to have a much higher rate of heart disease than moderate drinkers.

In fact, when figures from the research were recalculated, life-long teetotallers were healthiest, while moderate drinkers and "non-drinkers" had similar outcomes. The health of heavy drinkers also turned out to be much worse than previously believed.

"This reopens the debate about the validity of the findings of a protective effect for moderate drinkers," said Kaye Fillmore, a sociologist at the University of California at San Francisco's school of nursing and lead author of the study.

She was careful to add, however, that research has not proved or disproved the benefits of moderate alcohol consumption.

Rather, the new study has shown that methodology can be much better.

Tim Stockwell, director of the Centre for Addictions Research in British Columbia and co-author of the paper, said he suspects that, ultimately, moderate alcohol consumption will be shown to have some beneficial effect, but it will probably be much more modest than the flawed studies demonstrated.

"I'm still going to have a glass of wine with my dinner because it's an enjoyable, very low risk behaviour," he said.

Dr. Stockwell said his concern is that a lot of public policy and personal behaviour have been shaped by the notion that moderate drinking is good for the heart and for health in general, even though the science behind those conclusions is poor.

"This demonstrates that we're really hungry for information about what's good for our health," he said.

To conduct the new research, published in today's edition of the journal Addiction Research and Theory, the team of alcohol researchers from the United States, Canada and Australia reviewed 54 previously published studies examining the relationship between moderate drinking and health. Of that total, only seven did not inappropriately mingle abstainers and former drinkers.

None of those seven studies showed any significant benefit of moderate drinking. Just as importantly, Dr. Stockwell said, when the figures were recalculated compounding the two groups, they showed a health benefit to moderate drinking -- just like the 47 flawed studies.

This is not the first study to caution about drawing conclusions on the benefits or risks of alcohol based on limited data. Several other socioeconomic factors -- poverty, lack of employment, precarious housing -- have a much greater impact on health than does alcohol consumption.

A study published last year in the American Journal of Preventive Medicine showed, for example, that moderate drinkers tend to be wealthier, better educated, more active and better nourished than non-drinkers and heavy drinkers, and said that these characteristics, rather than the nightly glass of wine, explain their better health.

In other words, light drinking is a sign of good health rather than its cause.