Study Questions Health Benefits of Moderate Drinking

Health and Drinking

The majority of studies suggesting that "moderate" drinking helps prevent heart disease may be flawed, according to an international research group.

In a new report, researchers from the U.S., Canada, and Australia analyze 54 studies that linked how much people drink with risk of premature death from all causes, including heart disease. Researchers from the University of Victoria in British Columbia and the University of California, San Francisco led the team.

The researchers investigated a suggestion put forth in the scientific community that many of the studies conducted so far on drinking and premature death made a consistent and serious error by including as "abstainers" people who had cut down or quit drinking due to declining health, frailty, medication use or disability. When such studies show a higher death rate for abstainers than for moderate drinkers, this result may reflect the poor health of some abstainers who recently quit drinking rather than indicating a protective effect for alcohol.

The team found only seven studies that included only long-term non-drinkers in the "abstainers" group. The results of the seven studies showed no reduction in risk of death among the moderate drinkers compared with abstainers. When the researchers combined the data from these studies, they showed that it was possible to perform new analyses that appeared to show a protective effect of moderate drinking--but only when they deliberately included the error of combining long-term abstainers with people who had cut down or quit drinking more recently.

The authors caution that their report, published online in advance of the May 2006 issue of Addiction Research and Theory, has not disproved the notion that light drinking is good for health, as too few error-free studies have been performed. They suggest, however, that the extent to which these benefits actually translate into longer life may have been exaggerated.

"The widely held belief that light or moderate drinking protects against coronary heart disease has had great influence on alcohol policy and clinical advice of doctors to their patients throughout the world," said Tim Stockwell, PhD, of the Centre for Addictions Research at the University of Victoria. "These findings suggest that caution should be exerted in recommending light drinking to abstainers because of the possibility that this result may be more apparent than real."

"We know that older people who are light drinkers are usually healthier than their non-drinking peers," said Kaye Fillmore, PhD, of the UCSF School of Nursing. "Our research suggests light drinking is a sign of good health, not necessarily its cause. Many people reduce their drinking as they get older for a variety of health reasons."

The authors emphasize that there is a need for more well-designed research in the future that assesses people's alcohol intake and abstinence more precisely as their drinking patterns change with age.

META-ANALYSIS

The research that the team analyzed consisted of prospective studies, including hundreds of thousands of individuals who were followed over a number of years. Most studies were from North America and Europe, some from the Caribbean and Asia. The majority of the results were published in the 1980s and 1990s, with one study published in 1974 and one as recently as 2004.

The team investigated this body of research using meta-analysis