Story highlights

Scientists did a review of 87 studies about health and alcohol

They didn't see the positive health impact some headlines tout

There may be a bias in how the studies group drinkers

CNN  — 

Now here’s some news that may have you crying into your beer. Alcohol, when consumed in moderation, may not improve your health after all.

Over the years we’ve all seen the studies that show a glass of wine a day may help protect you from developing heart disease, will help with cancer and keep type 2 diabetes away, and will ultimately help you live longer. But this new research may be a buzz kill for those who like to drink in moderation. Toasting to your health may actually be an oxymoron.

So, belly up to the bar and we’ll explain what the scientists behind this new meta-analysis running in the latest edition of the Journal of Studies on Alcohol and Drugs think happened with the earlier studies that show the health benefits of moderate drinking.

This team of scientists looked at a wide variety of studies on the topic, specifically looking at alcohol’s impact on mortality. Narrowing their list down to 87 studies, the authors found the majority of them may have been coming to conclusions based on what the authors label as “biased” data.

It’s not that the other scientists were working under the influence of the industry or something more potent. This latest study found that when those other studies divide people into groups they typically put them into common categories: heavy drinkers, moderate drinkers, occasional drinkers and abstainers.

What the new study found is that the abstainer group isn’t only made up of people who have never touched a drop. Instead, some in this group may be recovering alcoholics. Some may also be abstaining now because of a health condition. In general, those two groups of people in the abstainer category are not as healthy as those who are lifelong teetotalers, research shows. That means these less healthy people skew the data. So, the moderate drinkers end up looking healthier by default. Make sense?

Of the 87 studies, 13 did separate out the lifelong abstainers from the former drinkers. The studies that controlled for these sicker people found that moderate drinkers had no health advantage over the true nondrinkers. When this team reran the data they considered appropriate against other studies, using these much narrower definitions of abstainers, they saw the same results: The moderate drinkers were no better off than the abstainers.

You may be wondering: Why does this matter to anyone other than the scientists who study alcohol?

“Alcohol has played such a central part of many people’s lives and is embedded in various occasions and relationships, so there is a lot of interest on this topic,” said co-author Dr. Tim Stockwell. “Understanding this question is important as we shape alcohol policy.”

Some earlier studies have also chipped away at the idea that there are health benefits to moderate drinking. A study that ran in BMJ last year suggested there was no sign that you lived longer because you drink a little as opposed to abstaining. Other studies have come to different conclusions, showing some benefits. (If you are a heavy drinker, that’s a different story. Your life will likely be shorter.)

“Determining how a low dose of alcohol impacts your life is complicated work,” said Aaron White, the senior scientific adviser to the director of the National Institute on Alcohol Abuse and Alcoholism. He said relying on self-reported data, remembering how much you drank a month ago, is difficult. There is a real need for randomized control trials to truly see what impact drinking has on human health.

The Centers for Disease Control and Prevention guidance on drinking hedges its bets a little and mentions that recent studies have called the health benefits of drinking into question, while still offering guidance that there could be some protective qualities to drinking. The guidance adds that y