Moderate drinking won't prolong your life, new research indicates

NEW YORK, July 25 (UPI) -- Moderate drinking won't lengthen your life, a new report suggests, challenging earlier findings that a glass of wine a day is healthy.

That report, generated by the Canadian Institute for Substance Use Research at the University of Victoria in British Columbia, Canada, appeared Thursday in the Journal of Studies on Alcohol and Drugs -- from the Center of Alcohol & Substance Use Studies at Rutgers University in New Jersey.

Researchers said previous recommendation touting the life-extending benefit of wine relied on flawed scientific research.

Multiple studies have indicated that moderate drinkers live longer than nondrinkers due to the decreased risks of heart disease and other chronic illnesses. This led to the popular belief that alcohol intake, within reasonable limits, can be a wellness tonic.

But not all studies have portrayed alcohol in such a positive light -- and this new analysis explains why.

The public should "be skeptical of claims that alcohol use in moderation may prolong life and reduce the risk of serious health conditions and premature death," the study's lead author, Tim Stockwell, a scientist at the Canadian Institute for Substance Use Research, told UPI via email.

"Drinking less or not at all is more consistent with improving health and well-being," added Stockwell, who also is a professor emeritus and adjunct professor in the Department of Psychology at the University of Victoria.

The studies that show a favorable impact from alcohol use typically focused on older adults and failed to consider people's lifetime drinking habits, Stockwell said.

They compared moderate drinkers with "abstainer" and "occasional drinker" groups that included some older adults who had quit or lowered their alcohol consumption because they had developed health conditions, he added.

"This makes people who are able to keep on drinking look very healthy by comparison," Stockwell said, noting that looks can be deceptive.

For this analysis, researchers identified 107 published studies that followed people over time and examined the relationship between drinking habits and longevity.

When they amassed all the data, it appeared that light-to-moderate drinkers -- those who imbibed between one drink per week and two per day -- had a 14% lower risk of dying during the study period compared with abstainers.

That changed, however, when researchers probed more deeply. Moderate drinking was not associated with a longer life in a handful of "higher quality" studies, researchers said.

These studies included people who were relatively young at the outset (younger than 55, on average) and had ensured former and occasional drinkers were not considered "abstainers."

Instead, it was the weakest studies -- involving older participants with no differentiation between former drinkers and lifelong abstainers -- that linked moderate drinking to greater longevity.

"Well-designed, high-quality studies did not find health benefits," Stockwell said. "Poorly designed, low-quality studies found large benefits."

The concept that moderate drinking leads to a longer, healthier life can be traced back decades.

For instance, researchers alluded to the "French paradox" -- an idea popularized in the 1990s that promoted red wine as helpful in explaining why French people experience relatively low rates of heart disease, despite a rich, fatty diet.

In reality, moderate drinking likely does not lengthen people's lives -- rather, it comes with some potential health hazards, including heighted risks of certain cancers. That's why no significant health organization has ever set a risk-free level of alcohol intake, the researchers noted.

However, this study shouldn't be the basis for establishing drinking guidelines, said Stockwell, who has studied alcohol consumption and its hypothetical health benefits for about 25 years.

"The great majority of deaths are not due to alcohol, so the results are likely confounded by lifestyle and other uncontrolled factors," he said.

"Our study was really about how misleading the majority of such studies are -- and how the appearance of health benefits vanishes when studies use more rigorous methods."

He added that "our research casts further doubt on the comforting idea that moderate drinking has health benefits."

Dr. Tyler Saunders, an internal medicine physician at Endeavor Health in Chicago, said alcohol consumption has a negative impact on patients' lives. He was not involved in the study.

For instance, drinking lowers metabolism, interfering with weight loss. Alcohol also causes specific changes in body composition, increasing belly fat, which is directly related to cardiovascular risk and inflammation, Saunders said.

In addition, he noted that alcohol decreases rapid eye movement sleep, a stage in which most dreams occur. REM sleep also may affect learning, memory and mood.

"I don't think we can conclude that no one should drink from this study alone. More research is needed before making such a statement," Saunders said.

"However, for those trying to improve their health -- diet, sleep and energy -- studies like this may prompt us to reconsider regular, consistent alcohol consumption," he said.

Based on the most recent and more rigorously designed studies, there are no levels of alcohol use that provide overall health benefit, said Dr. Brian P. Lee, who specializes in liver disease at the Keck School of Medicine of the University of Southern California in Los Angeles.

"This current study shows how and why prior studies that did show benefit were flawed," Lee said, adding that it's important for health care providers "to be consistent with our messaging to the public -- you may like alcohol and it may be enjoyable, but it doesn't prolong your life."

For those who consume alcohol, the study suggests that "it is safest, both in the near-term and over prolonged periods of time, to drink in moderation," said Dr. Martin Plawecki, an investigator in the Indiana Alcohol Research Center at Indiana University School of Medicine in Indianapolis.

Plawecki, who also is an associate professor of psychiatry, cited the National Institute on Alcohol Abuse and Alcoholism's recommendation that "drinking less is better for health than drinking more."