Does Alcohol Cause Dangerous Bacteria Growth On Teeth?

A new study, published online in the journal Microbiome and reported on by CBS News, examined the relationship between alcohol consumption and oral bacteria. Specifically, it looked at levels of and types of bacteria in the mouths of self-identified non-drinkers, moderate drinkers, and heavy drinkers, defined as drinking more than the recommended limit of one drink per day for women or two drinks per day for men.

As we develop a better understanding of the importance of a healthy oral environment, studies like this can tempt us to look at a single study and think we have the definitive word on a subject, so it’s important to consider any one study in a broader context.

Studies examining the links between alcohol consumption and its health effects have shown decidedly mixed results. For a long time, moderate alcohol use, particularly drinking red wine, was reported to be beneficial to overall health, probably because of its high antioxidant concentration. In contrast, a more recent study questioned whether any alcohol consumption at all was beneficial. Basically, the data available does not give an easy common ground.

So, what does this study tell us about the relationship between oral bacteria and alcohol use?

According to study data, it appears that heavy drinkers seemed to have more “bad” bacteria—ones that we know increase heart attack and stroke risk, and that individuals who drank less had oral environments that favor the so-called “good” bacteria.

How does this fit in the context of what we know?

We know for certain that the environment influences or provides the selection pressure for which bacteria will be found in a biofilm, wherever it is, including the oral biofilm. Further, it is always tempting to label certain bacteria good and some bacteria bad. In reality, it’s not that cut and dried. In the mouth, we have seen that “good” bacteria can act like “bad” bacteria under the right (or maybe the wrong) conditions. The behavior of the oral biofilm, because bacteria in a biofilm behave differently than they do individually, is just as important as which types of bacteria are present.

So what can we confidently take away from this most recent study?

This study has demonstrated, along with a large body of other research, that heavy alcohol use is not healthy. It may also contribute to the collection of known unhealthy bacteria and a “wrong” biofilm in the mouth. While it does not prove that alcohol causes bad bacteria to overgrow, it does suggest that heavy drinking may help it overgrow.

The results for mild or moderate alcohol use are not as clear. Does minimal to moderate consumption of alcohol have a health benefit? That’s a good question at this point. The best recommendation for those who would prefer to consume alcohol is probably found in an adage: “moderation in all things.”