Persistent dental plaque may increase the risk of dying early from cancer, according to authors of a study published in the journal BMJ Open.
Dental-plaque levels were higher in the 35 people who died from cancer than in the rest of the 1,400 study participants tracked over 24 years in Sweden. Demographic data showed the women should have lived 13 more years and the men an extra 8.5 years, so the deaths would be considered premature, said the authors, led by Birgitta Soeder, professor emerita of preventive dentistry at the Karolinska Institute in Stockholm.
Dental plaque is made up of bacteria covering the surfaces of the teeth and may lead to tooth decay and gum inflammation. The researchers, who said the study only found an observed association between dental plaque and cancer, said toxins from plaque may enter the blood to spread to different parts of the body “with potential systemic consequences.”
“The high bacterial load on tooth surfaces and in gingival pockets over a prolonged period of time may indeed play a role in carcinogenesis,” the authors said in the published paper. “Further studies are definitely required, however, to determine whether there is any causal element in the observed association reported here.”
Earlier studies have suggested people with severe periodontal disease may be at increased risk for developing diabetes, and infections around the teeth may be a signal of heart disease. Statistical analysis of the research in Sweden made adjustments for some potential risk factors associated with premature death, such as education, smoking, frequency of dental visits and income level.
Still, “this association may not be causal,” Paul Pharoah, lecturer in cancer epidemiology at the University of Cambridge in England, said in an e-mailed statement. “Although some factors were controlled for, there are very likely to be other factors, such as diet and obesity, that would be associated with both plaque and mortality.”