Is Flossing Good for Your Heart?
In fact, Hujoel comments, "The biggest challenge in studying this kind of association is that the risk factors for gum disease are very similar to the risk factors for heart disease. For instance, a textbook example is smoking: It is probably one of the biggest risk factors for gum disease, and it is very well known that it is also a risk factor for heart disease. So given that there are so many common risk factors for both diseases, it is very difficult to completely eliminate any [confusion between the risk factors] that may be occurring."
During the follow-up, about 15% of the participants had either died of heart-related causes, been hospitalized for heart disease or had surgery to clear up blocked arteries.
Overall, the researchers found that people with gum disease were two-and-a-half times more likely than those with healthy gums to experience a medical "event" related to heart disease. But when they took into account the other heart disease risk factors (such as diabetes, smoking, obesity, etc), they found that people with gum disease were not at greater risk for developing heart disease.
"Some people strongly believe there is a link [between gum disease and heart disease], but the evidence is pretty strong that we are looking at a small association," says Hujoel, pointing out that his study did find a small but insignificant link.
"It is very difficult in my opinion to draw a causal association," Andy Teng, DDS, PhD, tells WebMD. Teng, a periodontist and an oral pathologist at the University of Western Ontario, was not involved in the study.
But Teng says that just because there isn't a causal connection, doesn't mean there isn't some other kind of association. "[Gum] disease could be an important modifier of heart disease. ... I personally believe we are looking at something that would modify the [heart] disease progress, either slow it down or exacerbate the progression."
Other experts agree. Jeffrey Ebersole, PhD, is the director of the Center for Oral Health Research at the University of Kentucky in Lexington. He tells WebMD, "This infection, in and of itself, is not enough to trip the balance, but if you superimpose upon that a number of other cardiovascular risks within a patient, that might be something that will push them off a cliff, relative to an event."
Mitchell Elkind, MD, tells WebMD, "Because [gum] disease is so prevalent and so common ... we might need a much larger study to find an association. But if there is even a small association then, extrapolated over the number of people with [gum] disease in the U.S., that could be significant way to intervene and help people." Elkind is an assistant professor of neurology at Columbia University's College of Physicians and Surgeons.