Patients with gum disease may have a 25% higher risk of having gastric cancer (GC) in the stomach lining in the area closest to the esophagus compared to those with healthy teeth. The study was recently published in BMC Oral Health.
This study offers further evidence linking poor oral health to stomach cancer, the authors wrote.
“Our findings suggest that individuals with odontogenic inflammation are at higher risk of developing GC,” wrote the authors, led by Zengliang Ruan of the Southeast University School of Public Health in China (BMC Oral Health, July 21, 2025, Vol. 23, 434).
This study analyzed data from Sweden’s population-based Dental Health Register, which includes dental health records and tooth counts for adults ages 19 and older who visited a dentist between 2009 and 2016. Researchers grouped participants based on dental health conditions, including caries, root canal infection, mild inflammation, and periodontitis, they wrote.
GC diagnoses were identified using the Swedish Cancer Register and classified by the International Classification of Diseases. Also, the analysis accounted for age and other confounding factors to further explore links between oral health and GC risk.
Poor dental health was linked to a higher risk of GC, while having more remaining teeth was associated with a lower risk. Compared to individuals with healthy teeth, those with periodontitis had an 11% increased risk of GC (95% confidence interval [CI]: 1% to 21%) and a 25% increased risk of cardia GC (95% CI: 7% to 46%), they wrote.
Additionally, the risk of both cardia, cancer that starts in the upper part of the stomach near the esophagus, and non-cardia GC, which develops in the main body of the stomach, rose gradually as the number of teeth decreased.
Associations between dental health and non-cardia GC in men, women, and older adults were only marginally significant. Sensitivity analyses confirmed the link between poor dental health, fewer teeth, and increased GC risk.
The study, however, had limitations. The data did not include lifestyle factors like diet, alcohol use, and smoking, so researchers could not directly account for their impact, the authors added.
“Promoting dental health in the general population could have significant public health implications in preventing this disease,” Ruan and colleagues concluded.
