April 18, 2012 -- Contrary to what had been "accepted" thinking by many, there is no conclusive evidence that gum disease causes heart attacks and strokes, or that treating gum disease will improve heart disease, according to a new scientific statement by the American Heart Association.
Gum disease is a major reason that adults lose their teeth. And in recent years, a growing number of studies have suggested that gum disease may pose other dangers to the body, too.
One theory holds that inflammation and infection that starts in the mouth can spread, causing more widespread trouble. Research has tied gum disease to diabetes, heart disease, cancer, osteoporosis, stillbirths, and even Alzheimer's disease.
And a handful of studies, including one published in 2007 in the New England Journal of Medicine, have even shown that aggressively treating gum disease may improve some indicators of blood vessel function.
But after reviewing more than 60 years of research on heart and gum disease, experts say that although the two problems are clearly related, it is unlikely that gum disease causes heart disease.
Statement Aims to Clear up Confusion
The American Heart Association's statement comes on the heels of a campaign by the Institute for Advanced Laser Dentistry to launch a national "Gum Disease Awareness Week."
"Oral health has a major impact on overall health, and mounting university research has linked gum disease to serious health concerns, including heart disease, stroke, certain cancers, diabetes, and even stillbirths," Robert H. Gregg, DDS, president of the IALD, says in an April 11 news release.
The organization promotes laser treatment of gum disease, which it says on a Facebook page, "can hurt more than just smiles."
Researchers say statements like that may be jumping ahead of science, however.
"It was clear to everybody that there was a lot of confusion out there; a lot of conflicting scientific evidence. The public and the profession, both medicine and dentistry, had come to believe on the basis of the information that was out there that there was a direct connection between periodontal disease and [heart] disease," says researcher Peter B. Lockhart, DDS, chairman of the department of oral medicine at Carolinas Health Care System in Charlotte, N.C.
"There's no scientific evidence at this point that there's a direct connection -- that either gum disease causes atherosclerosis [hardening of the arteries] or strokes and heart attacks, or that there's any evidence at this point that by treating periodontal disease that you'll improve your [heart health] situation," Lockhart says.
Lockhart says the statement is meant to clarify what is known about the link between oral health and heart disease, and to encourage people to focus on more established heart disease risk factors like high blood pressure, high cholesterol, diabetes, and obesity.
The review doesn't mean that it's OK not to take care of your gums or that gum disease doesn't need treatment, he says.
"Having infected gums on a daily basis can't be healthy. It just, at this point, hasn't been shown to cause disease [throughout the body]," Lockhart says.
"I wouldn't want people distracted nor needlessly upset by the fact that if they couldn't get dental care or it wasn't working that it was going to have a negative impact on their overall cardiovascular situation," he says.
Statement Stirs Controversy
Other experts, however, say they were confused by the new statement.
"I think it's a bit dangerous," says Suzanne Steinbaum, MD, a preventive cardiologist at Lenox Hill Hospital in New York. "What they're really saying is that maybe it wasn't that poor dental hygiene is associated with heart disease; it's more that the risk factors are similar, and therefore we're seeing a connection."
But "how much does it matter?" she says, given that people still need to take care of their gums for other reasons.
And other experts said they felt the conclusions of the review were being misinterpreted.
Kenneth S. Kornman, DDS, PhD, editor of the Journal of Periodontology, said the review found that there is an independent association between heart disease and gum disease. That means that people who have one are also more likely to have the other. That's true even if they don't smoke or have diabetes, two things that are known to drive up the risk for heart and gum disease. It's not yet known why the two frequently occur together.
He said it's also true that there's no evidence to show that gum disease causes heart disease, but that's because studies that could prove that have not been done.
"We have to be careful," Kornman says. "We don't want to say to the public, [gum disease] doesn't cause heart disease. The fact is that we don't know."
Still, Lockhart says people deserve to understand that the benefits of treating gum disease may be more limited than they had believed.
"We have to tell patients what we know and not what we think," he says.