Your Weekly Checkup: Can Gum Disease Lead to Heart Attacks or Cancer?

“Your Weekly Checkup” is our online column by Dr. Douglas Zipes, an internationally acclaimed cardiologist, professor, author, inventor, and authority on pacing and electrophysiology. Dr. Zipes is also a contributor to The Saturday Evening Post print magazine. Subscribe to receive thoughtful articles, new fiction, health and wellness advice, and gems from our archive. 

Order Dr. Zipes’ new book, Damn the Naysayers: A Doctor’s Memoir.

As a youngster growing up without fluoride in the water, I had a gazillion cavities in my teeth. Now, as a senior citizen, I’ve paid the price with root canals, caps, and transplants. Through it all, however, I’ve tried to maintain the best dental hygiene possible to avoid losing more teeth, getting more cavities, and having bad breath. That turns out to be a simplistic notion because we now need to also think about the risks of cardiovascular disease and cancer.

Periodontal disease is a chronic inflammatory process caused by bacteria affecting the soft and hard structures holding the teeth in place. Being male, current cigarette smoking, and diabetes mellitus are important risk factors for developing periodontal disease. The disease appears to be pervasive, affecting up to 90% of the population worldwide. Half of Americans aged 30 or older have periodontitis, and the inflammation, which can affect the entire body (be systemic), can be associated with heart attacks and strokes. Recent studies suggest a rise in the incidence of stroke worldwide and have reported an association between periodontal disease and stroke. These reports suggest that stroke has a stronger association with periodontal disease than coronary artery disease.

Preventing and treating inflammation is an important component for maintaining good cardiovascular health. For example, the ARIC (Atherosclerosis Risk in Communities) sub study assessed dental hygiene and stroke rates. They found that all categories of periodontal disease were associated with higher rates of stroke when compared with the perfectly normal group without periodontal disease or inflammation. Those in the worst periodontal disease category had more than twice the risk for stroke. Importantly, the ARIC study found that patients who received regular dental care had a 23% less risk of stroke compared with those patients receiving episodic care. The important message is that regular dental care can reduce the stroke risk. An increase in tooth brushing frequency decreases the concentrations of systemic inflammatory markers in the blood.

In addition, a paper published in the Journal of the National Cancer Institute indicated that individuals with severe gum disease may be at greater risk for developing multiple types of cancer compared to those with no or mild gum disease. Dental exams were performed on more than 7,400 people. Researchers found that after 15 years, individuals with severe gum disease had a 24 percent higher risk of developing any kind of cancer. The risk for lung cancer was more than doubled for those with severe gum disease compared to those with no or mild gum disease. The risk of developing colorectal cancer was increased as well, especially in the group of nonsmokers who had severe gum disease.

The message is clear. As a part of staying healthy, see your dentist regularly, floss and brush your teeth frequently.

Brushing Up on Oral Hygiene

Experts concur that good dental hygiene is an important tool in managing diabetes.

It’s been called a two-way street, a bidirectional arrow, a loop and a vicious circle.

“It” is the complicated connection between two seemingly unrelated conditions: diabetes and periodontal disease. The reason researchers are beginning to understand it as a not-so-merry-go-round is because not only is poorly controlled diabetes a major risk factor for gum disease, but in turn, untreated gum disease can make diabetes worse or even hasten the progression to diabetes in those at high risk of developing the disease.

But whatever you call this relationship, it’s one that’s not well known or understood.

“I never knew there was a connection between oral care and diabetes. No doctor or dentist ever said anything about it,” says Louise Sherby, 61, a college librarian in New York City. Diabetes runs in Sherby’s family, and three years ago, in the course of testing for minor surgery, she was told she had prediabetes.

Like many people, Sherby had no symptoms. (That lack of signs is one reason a third of the almost 24 million people in this country with type 2 don’t yet know they have it.) “Dental care is prominent for me not because of diabetes but because of a childhood of having lots of cavities,” she adds, “but now I intend to be extra vigilant.”

Bacteria that are normally present in the mouth can produce toxins that irritate the gums, leading to infection and inflammation—and inflammation is mixed up in almost all major chronic diseases, from Alzheimer’s to osteoarthritis. Periodontal disease, which starts in a milder form called gingivitis, is a chronic ailment that eventually can destroy tissues and even bone. Despite its destructiveness, it’s often painless and most people don’t know they have it. Smoking and a genetic predisposition, along with diabetes, can make gum disease worse.

So how can diabetes, a disorder of glucose (blood sugar) control, have anything to do with infection in the mouth?

“People who are diabetic tend not to respond well to infection. Whenever you have bacteria and a reduced ability to fight it, you’re liable to have more disease,” explains Michael S. Reddy, D.M.D., chairman of the department of periodontology at the University of Alabama at Birmingham School of Dentistry. “People with diabetes have worse infections in general for this reason, so their periodontal disease might also be worse.” Think of how you always seem to catch a cold when you’re run-down, and you’ll get the idea of how diabetes diminishes the ability to fight off bugs.

“People who have a healthy immune system can have a mouth loaded with plaque, but their immune system can handle that challenge,” says Casey Hein, B.S.D.H., M.B.A., associate professor in dental hygiene at the University of Colorado School of Dental Medicine and a dentistry faculty member at the University of Manitoba, Winnipeg. “But for a patient whose immune system is not as resilient, a little plaque could send them from gingivitis to periodontal disease.”

And periodontal disease increases the risk of losing teeth, “which is not just a quality of life problem,” notes George L. King, M.D., director of research at Joslin Diabetes Center, Boston, and a professor of medicine at Harvard Medical School. “People who have bad teeth or don’t have teeth (even with dentures) have poor nutrition, which leads to more problems. Nutrition is a huge part of diabetes care.”

Treating the mouth is also an important element of managing diabetes. One small study, of Pima Indians in Arizona who had both advanced gum disease and type 2, found that when their gum problems were treated, their diabetes improved. Dr. Reddy is beginning an NIH-funded study to see if these results hold true for a larger population. “It’s worked in small studies and is promising,” he comments.

Also promising is that dentists and physicians are beginning to keep an eye out for each other’s patients. In general, many who treat type 2 have not emphasized good oral hygiene, even though almost a third of people with diabetes have severe gum disease.

In addition, says Hein, health insurers are considering increasing dental benefits as evidence mounts that good oral hygiene can pay off by reducing more severe medical troubles.

“Most adult periodontal disease can be prevented or fixed. So if there is a dental component to diabetes, then that is one aspect of diabetes we can control,” Dr. Reddy says. “That’s the good news: Good dental care can really make a difference.”