Is Flossing Good for Your Heart?
Hujoel and his colleagues looked at data from a large government study that tracked more than 8000 subjects, aged 25 to 74 years old, between 1982 and 1992. At the start of the study in 1971 to 1975, none of the subjects had a history of heart disease, although more than half of them had some type of gum disease, either periodontitis or gingivitis (both of which involve inflammation of the gums).
The researchers noted that the participants with gum disease tended to be male, less educated, black, and poorer than the study participants with healthy gums. They also were older and were more likely to have other heart disease risk factors, including diabetes, high blood pressure and high cholesterol levels, being overweight and smoking.
In fact, Hujoel comments, "The biggest challenge in studying this kind of association is that the risk factors for gum disease are very similar to the risk factors for heart disease. For instance, a textbook example is smoking: It is probably one of the biggest risk factors for gum disease, and it is very well known that it is also a risk factor for heart disease. So given that there are so many common risk factors for both diseases, it is very difficult to completely eliminate any [confusion between the risk factors] that may be occurring."
During the follow-up, about 15% of the participants had either died of heart-related causes, been hospitalized for heart disease or had surgery to clear up blocked arteries.
Overall, the researchers found that people with gum disease were two-and-a-half times more likely than those with healthy gums to experience a medical "event" related to heart disease. But when they took into account the other heart disease risk factors (such as diabetes, smoking, obesity, etc), they found that people with gum disease were not at greater risk for developing heart disease.
"Some people strongly believe there is a link [between gum disease and heart disease], but the evidence is pretty strong that we are looking at a small association," says Hujoel, pointing out that his study did find a small but insignificant link.