In a study of more than 60,000 dental patients, those with gum disease were twice as likely to have had a heart attack, stroke or severe chest pain.
Previous studies have linked periodontitis and clogged arteries, but this is the first to investigate the link in a group of people this large, the researchers say.
At the Academic Centre for Dentistry Amsterdam, the largest dental school in the Netherlands, investigators reviewed the medical records of 60,174 patients age 35 and older, looking for an association between periodontal gum disease and atherosclerotic cardiovascular diseases such as angina, heart attack and stroke.
About 4 percent of patients with periodontitis had atherosclerotic cardiovascular disease, compared to 2 percent without periodontitis, the researchers found. Even after taking other risk factors for cardiovascular disease into account, such as high blood pressure, high cholesterol, diabetes, and smoking, those with periodontal disease were still 59 percent more likely to have a history of heart problems, according to a report in the Journal of Epidemiology and Community Health.
In periodontal disease, the advanced stage of the gum disease gingivitis, the gums pull away from the teeth and create pockets that can become infected. Periodontitis has also been tied to other conditions such as skin disease and dementia. "It's clear that periodontitis is associated with chronic inflammation, so it makes sense biologically that if you have a heavy infection in your mouth, you also have a level of inflammation that will contribute to heart conditions," said Panos Papapanou of Columbia University in New York, who has studied the association between gum disease and heart disease but wasn't involved in the current study.
The research team suggests that gum disease develops first and may promote heart disease through chronic infection and bacteria in the circulatory system.
Dr. Bruno Loos, the senior author of the new report, said by email that "plausible mechanisms to explain the relationship" may include a common genetic background for the way the body handles inflammation, oral bacteria and immune responses.
Still, this kind of observational study can't prove that gum disease causes heart problems.
"The association ... does not provide proof (of causation), even when the results from our study corroborate findings from previous similar research," study coauthor Geert van der Heijden said by email. Papapanou told Reuters Health that while the new findings are from patients with a relatively high socioeconomic status, "we're repeatedly seeing the same conclusion."
"It seems all over the globe we have to consider this relationship," Loos said.
In the U.S., heart disease is the leading cause of death, according to the Centers for Disease Control and Prevention. Each year, more than 600,000 people die from heart disease, which accounts for one in four deaths. Dr. Frank Scannapieco, chairman of the Department of Oral Biology at the University at Buffalo in New York, who wasn't involved with the study, commented to Reuters Health that while the association of periodontitis and coronary disease is "robust," the strength of the link is "moderate compared to traditional risk factors such as hypertension."
Papapanou advises: "Take care of your oral health for oral health itself. If you know there's a positive association between oral health and other diseases, would you ignore it? I wouldn't."