Explore more

The Rumor: Flossing can help prevent heart disease

You brush, you floss, you even use mouthwash (almost) every day -- all to keep your pearly whites in tip-top shape. And it's not for looks alone. After all, you've long been warned that having unhealthy gums could put you at risk for heart disease. Right?

Yes, for more than a century, the popular belief among doctors -- and their patients -- was that unhealthy gums triggered heart disease. More specifically, people thought that bacteria from diseased gums could enter the bloodstream during dental procedures and cause an infection, which could in turn trigger heart attacks and major systemic heart problems. 

Hundreds of studies over the years have explored the link between gum health and heart health, with mixed results. When the American Heart Association (AHA) recently decided to take a closer look at the issue, they found that all that time, the popular wisdom connecting gum and heart disease had been... wrong.

The Verdict: Gum disease doesn't cause heart disease

In 2012, the AHA did a 180 on the issue, releasing a statement saying that there really seems to be no causal connection at all between gum and heart disease. The AHA rechecked 537 peer-reviewed studies looking at whether poor gum health could trigger heart disease, and found that none could prove there was a causative link between the two. "There's a lot of confusion out there," says Peter Lockhart, DDS, who coauthored the AHA statement. "The message... that heart attack and stroke are directly linked to gum disease could distort the facts, alarm patients and perhaps shift the focus on prevention away from well-known risk factors for these diseases."

So how did doctors come to believe that gum disease caused heart disease in the first place? They'd observed for decades that a surprisingly large percentage of people who had heart attacks and strokes also had gum disease -- and vice versa, says Mark Wolff, DDS, a professor of dentistry at New York University. "Some of the periodontal bacteria were actually found inside the arteriosclerotic tract -- inside the blood vessels of the heart and the aorta," Wolff says. "So it looked pretty strongly [like the two diseases] were related."

As it turns out, the reality was a bit more complicated. Gum disease and heart disease are associated with "all the same risk factors, such as smoking and diabetes," says cosmetic dentist Thomas Connelly, DDS. "So if you smoke, you risk getting gum disease and heart disease. If you have diabetes, you tend to develop gum disease and heart disease." In other words, while gum and heart disease have similar risk factors, one doesn't cause the other.

That's great news for heart doctors; not so much for dentists. "It's a big de-motivator for us, isn't it?" notes Connelly. "That was the best way to get people to floss: 'Floss, or you could get heart disease.' But that's not the case anymore."

So hooray: You're no longer risking a crippling coronary if you forget to floss in the morning. But... it's still a good idea to do so. Think of your gums as an early warning system: Poor gum health could show that your general health isn't what it should be. And let's face it: Not flossing still leads to cavities -- and who wants to risk that?


About our partners' commitment to health >