Tooth Loss & Poor Oral Hygiene Linked to Higher Cancer Risk

Individuals who have lost teeth face a 16% higher risk of developing esophageal cancer, according to a large-scale study released this week by researchers at Dong-A University and Chung-Ang University in South Korea. The research, published in the Journal of Clinical Periodontology, also found that those brushing their teeth fewer than three times daily have a 14% increased risk of the same cancer.

The findings, presented at a commemorative event hosted by Dong-A Pharmaceutical and the Korean Academy of Periodontology on Tuesday, underscore a growing body of evidence linking oral health to systemic diseases, including cancers. Esophageal cancer, currently the sixth leading cause of cancer death globally, often presents with few early symptoms, earning it the moniker “silent killer.”

The study analyzed the health records and insurance claims of approximately 7 million South Koreans. Researchers determined that individuals with periodontal disease – an infection of the gums and bone supporting the teeth – exhibited a roughly 10% increase in esophageal cancer risk. Notably, this correlation remained consistent regardless of smoking or obesity status, suggesting a direct link between oral health and cancer development independent of established risk factors.

“This research is significant because it demonstrates a clear association between oral hygiene and esophageal cancer risk in a nationwide cohort,” said Dr. Jae-Yong Park, a gastroenterologist at Chung-Ang University College of Medicine, during his presentation. “Preventing esophageal cancer requires not only avoiding alcohol and tobacco but also maintaining diligent oral hygiene through proper brushing habits.”

The study also highlighted the importance of consistent oral hygiene practices. Individuals who skipped brushing before bed or maintained irregular brushing schedules showed an 8% increase in esophageal cancer risk. Those who did not use dental floss or interdental brushes experienced a 10% higher incidence rate.

Researchers theorize that inadequate oral hygiene leads to bacterial proliferation in the mouth, triggering chronic inflammation of the gums. When swallowing and eating, these bacteria travel to the esophagus, potentially causing persistent inflammation and disrupting the immune response, ultimately elevating cancer risk.

Further research from researchers at Chosun University Dental School has revealed a potential pathway extending this connection to colorectal cancer. Their work, focusing on the bacterium Fusobacterium nucleatum, suggests that certain oral bacteria can survive the acidic environment of the stomach and reach the colon, exacerbating inflammation and promoting tumor growth. The team identified a specific subtype, Fna C2, possessing acid-resistance mechanisms that allow it to thrive in the gut, contributing to a more favorable environment for cancer development. Experiments involving mice demonstrated increased tumor formation in those administered Fna C2.

“Our findings suggest that the oral microbiome plays a crucial role in influencing the gut environment and potentially impacting colorectal cancer development,” stated Professor Jung-Ki Kuk of Chosun University Dental School’s Oral Biochemistry Laboratory. “This opens up possibilities for targeted microbial therapies to address these imbalances.”

Experts emphasize that the mouth serves as a gateway to overall health, and neglecting oral hygiene can have far-reaching consequences beyond dental issues. The recommended routine remains consistent: brushing two to three times daily, flossing or using interdental brushes, and regular dental check-ups.