A few weeks before that, researchers from the Harvard School of Public Health reported a study of more than 51,000 male health professionals that showed that men who had gum disease, or periodontitis, were far more likely than those without it to get pancreatic cancer.

Other studies have shown links between gum disease and diabetes, heart disease, stroke, and even — though this is more controversial — pregnancy problems such as low-birth-weight infants.

The evidence is accumulating faster than you can say "Don’t forget to floss" that taking good care of your teeth — and treating gum disease aggressively — may be one of the best things you can do not just for your mouth but for your overall health.

With pancreatic cancer, for instance, previous studies had suggested such a link, but those studies were muddied because many participants smoked, and smoking is a risk factor for both diseases. This time, even among people who never smoked, gum disease was linked to a doubling of the cancer risk, said epidemiologist Dominique Michaud of the Harvard School of Public Health, the study’s first author. It’s still not clear, cautioned Michaud, whether that means the gum disease led to the cancer.

Chronic inflammation anywhere, including swollen gums, makes the body release nasty chemicals called cytokines that have been linked to many problems, including diabetes and heart disease. The crucial point, in other words, is that "oral infections have systemic effects," said Dr. Thomas Van Dyke , a professor of periodontology and oral biology at the Boston University School of Dental Medicine.

In some cases, these systemic effects are probably linked to the direct spread of oral bacteria through the bloodstream to other parts of the body.

In other cases, oral bacteria have been found in plaques in artery walls, though it is not clear whether these bacteria are a cause of heart disease or merely incidental, said Dr. Bruce Pihlstrom , acting director of the Center for Clinical Research at the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health.

But most of the systemic problems linked to periodontitis, which affects millions Americans to varying degrees, are believed to be problems of chronic inflammation.

The clearest example of that is the association between periodontitis and diabetes, said Dr. Robert J. Genco , a periodontologist at the University of Buffalo. He and others have shown that people with diabetes have more severe periodontal disease and have it at an earlier age than nondiabetics. And it’s a two-way street: People with diabetes who also have periodontitis have more trouble controlling blood sugar than diabetics without periodontitis.

It makes sense. Cytokines, such as those generated in chronic gum inflammation, can disrupt the system by which insulin, the hormone that escorts sugar into cells, sends chemical signals inside cells. This can trigger insulin resistance, which often leads to diabetes.

And obesity — long known as a major cause of diabetes, in part because fat cells in the abdomen pump out so many cytokines — is also now seen as a direct risk factor for periodontitis, said Genco.

Via The Boston Globe