Each Tooth Worth $30,000? Brushing Three Times Daily Cuts Cancer Risk 30%

As South Korea enters a super-aged society, oral health is emerging as a key indicator that goes beyond simple hygiene to influence overall physical health. In particular, a series of studies revealing links between tooth loss and cancer incidence are raising alarm.

According to a recent study published in the international journal *Oral Health & Preventive Dentistry*, a research team at Korea University analyzed 13,616 adults who participated in the Korea National Health and Nutrition Examination Survey (2010–2018). The study found that people who had lost eight or more teeth were 1.23 times more likely to have cancer than those who had lost none.

Similar results were confirmed in a large-scale longitudinal study. A research team from Seoul National University Hospital's Public Healthcare Center and Seoul Metropolitan Government-Seoul National University Boramae Medical Center tracked 3,845,280 adults who underwent oral examinations in 2009 over a 10-year period. The group with tooth loss showed higher incidence rates across multiple cancer types. By cancer type, colorectal cancer increased by 13%, liver cancer by 9%, stomach cancer by 8% and lung cancer by 4%. Those with gingivitis also showed 8% and 7% higher risks of liver cancer and colorectal cancer, respectively.

The association was particularly pronounced among those aged 50 and older. Tooth loss was found to raise overall cancer risk by 18% in this age group.

Experts point to chronic inflammation as the key underlying cause. Periodontitis is a representative chronic inflammatory disease caused by bacterial plaque. The problem is that the inflammation does not remain confined to the mouth but spreads throughout the body via the bloodstream. Experts explain that inflammatory mediators weaken immune function and over time create conditions conducive to the development of various diseases, including cancer.

Studies have accumulated showing higher cancer prevalence among periodontitis patients, and this tendency becomes more pronounced as the number of lost teeth increases. However, researchers also note that the possibility of "reverse causality" cannot be ruled out — cancer itself or immunosuppression from cancer treatment may worsen oral health.

Daily oral hygiene habits were also confirmed as an important variable. The Korea University team's analysis found that the cancer prevalence rate among people who brushed fewer than three times a day was 3.2%, compared with 2.2% among those who brushed three or more times daily. Brushing three or more times a day was associated with approximately 30% lower cancer prevalence.

Experts emphasize that tooth loss should not be dismissed as a simple sign of aging. Oral health can serve as a "warning signal" for overall physical health.

Lim Ji-jun, president of the Korean Dementia Oral Health Association, said, "Tooth loss can be a signal alerting us to problems with our overall health." He added, "In a super-aged society, oral health management at both the individual and national levels is needed for healthy aging."

"A single tooth is worth approximately $30,000, and it has a significant impact on healthy life expectancy," Lim said. "Proper brushing and plaque management alone can reduce the risk of not only periodontal disease but also pneumonia and dementia."

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