Bacteria and inflammation may underlie the long-observed connection between oral health and cardiovascular disease.
About two-thirds of people over 65 have gum disease — more formally known as periodontal disease. It starts when plaque, a sticky film of bacteria and food, builds up around the teeth. In its earliest stage, gingivitis, irritated gums can bleed easily. Left untreated, periodontal disease can worsen and, in its most severe form, cause the teeth to loosen and fall out.
Compared with people who have healthy gums, people with periodontal disease are about twice as likely to have a heart attack. Shared risk factors — including smoking, an unhealthy diet, or lack of access to health and dental care — may explain some of this association. However, some bacterial and viral infections also appear to increase the risk of heart attack and stroke. And growing evidence suggests that bacteria and inflammation may underlie the link between the mouth and the heart.
"Your mouth is a gateway to the rest of your body, so it’s not surprising that your oral health can affect your overall health and vice versa," says Dr. Tien Jiang, a prosthodontist in the Department of Oral Health Policy and Epidemiology at the Harvard School of Dental Medicine.
Hundreds of different types of bacteria occur naturally in the mouth. Some, fed by sugars, release acids that break down the outer layer of your teeth, causing cavities. Other types of bacteria form plaque that — if not removed by regular brushing and flossing — hardens into tartar, Dr. Jiang explains. Only a professional dental cleaning can remove these hard, calcified deposits.
Signs of gum disease
If you experience any of these signs, you may have periodontal disease:
- swollen, red, or tender gums
- gums that bleed easily
- pus between the teeth and gums
- bad breath
- buildup of hard yellow or brown deposits along the gum line
- teeth that are moving apart or loose
- dental appliances no longer fit well.
Bacteria on the move?
The bacteria responsible for periodontal disease can travel to blood vessels throughout the body. In fact, periodontal bacteria have been found in the fatty debris (atherosclerosis) that clogs arteries located far from the mouth — and in blood clots from people who have experienced heart attacks.
"In both gum disease and heart disease, we find bacteria in places where they’re not supposed to be," says Dr. Jiang. The body’s immune response to these misplaced bacteria triggers an outpouring of white blood cells. The resulting inflammation may lead to tiny clots and cause a heart attack or stroke.
In addition, many factors linked to a higher risk of heart disease—diabetes, high blood pressure, high cholesterol, and obesity — are all more common in people with periodontal disease, according to a 2021 review article about oral health and cardiovascular disease in the American Journal of Preventive Cardiology.
One way to treat periodontal disease is for dentists and hygienists to use manual scalers or ultrasound devices to scrape away tartar above and below the gum line. Known as scaling and root planing, this deep cleaning is more extensive than the twice-yearly cleanings people typically get at the dentist. But while treating periodontal disease may help bring down levels of inflammatory markers in the bloodstream, there’s limited evidence it can reduce heart attacks or other cardiovascular problems.
Preventing periodontal disease
To prevent gum disease, daily brushing and flossing is essential — and can even reverse gingivitis before it worsens. If you’ve slacked off on your flossing, you may notice a little bleeding when you start up again, says Dr. Jiang. When that happens, some people get nervous and stop flossing. But don’t worry; just get back into the habit and chances are the bleeding will improve within a few days, she advises. If it doesn’t, and you notice other signs of gum disease (see box), schedule an appointment with your dentist.
A healthy diet can also help, says Dr. Jiang. Most people know that hard or chewy candy and other sticky sweets promote cavities. But sugary drinks like sodas (especially if you sip them throughout the day) also feed the bacteria that cause cavities and gum disease. "That’s also true for refined carbohydrates that stick to your teeth, like crackers and breads made with white flour," says Dr. Jiang. What’s more, a sugary diet is itself associated with higher heart disease risk. For more information on dental health, see Harvard Health Publishing’s Special Health Report, Dental Health for Adults (/DH).
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