The gnarly plaque lurking on your gums and teeth may increase your chances of dying from cancer, new research suggests.
Many studies have linked oral health to chronic illnesses such as heart disease. This latest research, however, suggests that people who have more plaque on their teeth and gums are more likely to die prematurely from cancer.
The findings, which appear in the edition of BMJ Open, show only an association between plaque and a raised risk of early cancer death, and not a cause-and-effect relationship.
How the study was done
In the new study, nearly 1 400 Swedish adults were followed for 24 years. During this time, 58 of the subjects died, 35 from cancer.
Study participants were asked about smoking and other risk factors for cancer. Researchers examined dental-plaque buildup, tartar, gum disease and tooth loss among all participants. The individuals who died had more dental plaque covering larger surface areas of their teeth and gums than their counterparts who did not die during the study period.
Specifically, people with high amounts of dental plaque were 79 percent more likely to die prematurely, the study showed. That said, the absolute risk of any person with dental plaque dying early of cancer was low.
On average, female participants were 61 years old when they died and men were 60. Women would have been expected to live around 13 years longer, and the men an additional 8.5 years, the study authors wrote, so their deaths could be considered premature.
Inflammation may be to blame
The findings held even after researchers controlled for certain factors known to increase risk of cancer death. Although the study did not examine how the two may be connected, underlying inflammation may be the common denominator.
"Bacteria in the gums may trigger local inflammation, and these bacteria and inflammatory markers don't just stay where they are," said Dr. Joel Epstein, director of oral medicine at the City of Hope Cancer Center in Duarte, Calif. "They are measurable in the blood, so it becomes systemic and widely distributed."
Calling the new findings "interesting," Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, said they raise more questions than they answer.
"This study does not answer the question of whether or not dental plaque leads to cancer death," he said. "We only know how many people died, so we don't know if there is an increase in the incidence of cancer among people with plaque, or if, perhaps, it renders them more susceptible to treatment-associated infection."
The findings make sense to Saul Presser, a dentist in private practice in New York City.
"There have been reports recently of a connection between certain cancers and oral plaque accumulation," he said. "When one has a lot of dental plaque, this means that more microorganisms are present than if there was minimal plaque in the mouth. It has been shown that certain cancers can be related to some viruses and other microorganisms."
Good reason to keep teeth free of plaque
It is too early to say that this plaque directly causes cancer, he said, but "it would be wise for patients to minimise their oral plaque through good oral hygiene and regular dental exams and professional cleanings."
Epstein said the findings demonstrate the interconnectedness of the human body.
"This is interesting and impactful data that broadens the whole view of not being able to separate the mouth from other body parts," he said.
Caring for your teeth
Learn more about healthy teeth and gums at the American Dental Association.
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