Studying the link between the heart and periodontal disease

Remember when mama told you to brush after every meal? And that you should visit your dentist twice a year? Did you figure she was giving you a tool to lower your risk of heart attacks? Huh? What relationship do your teeth and your heart have other than the fact that they live in the same body?

The issue here is periodontal disease. It’s the most common chronic infection in us humans. Periodontal disease is caused by bacteria that like to hang out between the gums and the teeth in the form of plaque. Plaque leads to inflammation which, in its mildest form, is called gingivitis. The gums get red and puffy, and they bleed easily. Good brushing and regular trips to the dentist usually fix the problem.

If left untreated, gingivitis can lead to full- blown periodontal disease. The plaque finds its way to the space between the gums and the teeth. The stuff is irritating, and the body mounts an inflammatory response, leading to destruction of the gums and the bone supporting the teeth. The teeth get loose and eventually might need to be removed.

That’s all pretty grim, but what does it have to do with heart attacks? Numerous studies over the past several years have identified a link between heart attacks and periodontal disease. When researchers look at the risk factors associated with heart attacks, they find that periodontal disease is an independent risk factor, like high cholesterol, high blood pressure and smoking. (By the way, smoking is a significant, maybe the most significant, risk factor for periodontal disease as well.)

Is this just a chance association? Or does periodontal disease somehow cause heart attacks? No one knows yet. But researchers will not be daunted.

Once they identify an association, they want to figure out why. One thing they do know is that inflammation plays a role in both diseases.

Researchers in Australia designed a study to see if treating periodontal disease would reduce the level of certain “markers” in the blood known to be associated with heart disease risk. Their 67 subjects had really severe disease – severe enough to require the removal of all their teeth. Pretty drastic, but a maneuver that cured them of any periodontal disease.

The researchers drew blood from the patients at three different times – before removal of the teeth, one to two weeks after removal, and again 12 weeks after removal. They checked for signs of inflammation (C-reactive protein in all, white blood cell count in some) and factors in the blood that increase the risk of blood clots.

They found that both the markers of inflammation and of clot promotion decreased significantly after the teeth were removed.

We now know that inflammation and blood clots play an important role in the genesis of heart disease. Germs can directly damage the lining of blood vessels. The same germs involved in periodontal disease have been found in the plaques (same name, different entity), or “atheromas” that line blood vessels in people with both heart disease and periodontal disease.

Inflammatory cells can cause plaques in the blood vessels to weaken and break open, stimulating blood clotting and leading to blockage in the blood vessels supplying blood to the heart. Increased levels of clotting factors cause the blood to clot more easily.

This study did not last long enough to see if the folks who had all their teeth removed, and thus were cured of their periodontal disease, went on to have fewer heart attacks. But the study authors did come up with a plausible explanation for why periodontal disease can lead to heart disease.

Now, no one is suggesting that we go out and have all our teeth pulled. In fact, improved dental care means that we are likely to keep our own teeth with us to the end.

But in order to do that, we need to remember what Mama said. Brush and floss regularly and pay a visit to your dentist every six months.