Brushing and flossing your teeth are certainly important for keeping your mouth healthy, but some evidence suggests that the state of your gums is associated with risk of getting cancer—and not just cancer of the mouth.
Background: This isn’t the first time that gum disease, or periodontitis, has been linked to health beyond the mouth. The association between gum disease and cardiac health is somewhat controversial, though, as there is no evidence that preventing or treating gum disease can reduce cardiovascular disease. But several small studies have found links between gum disease and certain types of cancer.
Study: Researchers used data from the Women’s Health Initiative, a very large study that began in the late 1990s with healthy postmenopausal women. At the beginning of the study, all of the women answered questions about their health and lifestyle, and annual questionnaires collected afterward captured health outcomes and more information about various risk factors. This particular analysis included only women who responded to the questionnaire that asked specifically about oral health. Women who already had been diagnosed with cancer were excluded. In total, information about 65,860 women was included in this analysis. The researchers then looked for associations between self-reported gum disease and different types of cancer.
Results: More than 7,000 cancers developed in the study group after an average of slightly more than eight years and about 17,100 women reported gum disease. Women who reported having gum disease were more likely to report smoking, secondhand smoke exposure, alcohol consumption and cancer diagnosis. There were no differences in body mass index, physical activity or diabetes between people who reported gum disease and those who did not. After adjusting for age, body mass index and smoking, having gum disease was associated with 14% increased risk for any type of cancer, 13% increased risk for breast cancer, 31% increased risk for lung cancer, 23% increased risk for melanoma, and 73% increased for gall bladder cancer. Cancer of the esophagus, though, was three times more likely for women with gum disease.
Surprising finding: When only people who never smoked cigarettes were included, risk for any cancer was still higher for women with gum disease (12% increased risk), but risks for breast cancer or lung cancer were no longer increased. Melanoma was 42% more likely among nonsmokers with gum disease, and cancer of the upper gastrointestinal tract (the esophagus and stomach combined) was more than twice as likely.
Bottom line: This is not the first study to find associations between gum disease and cancer, but it is the first in women only and among the largest. The strongest association was found between gum disease and esophageal cancer. Although this study does not prove that gum disease causes any type of cancer, including esophageal cancer, a plausible explanation for the association may be a matter of simple geography. Bacteria and other pathogens from the mouth move most easily to the esophagus, an adjacent area, through normal ingestion of saliva.