A recent study from the University of Osaka highlights the link between high blood sugar and an increased risk of tooth decay. Researchers discovered that elevated blood sugar levels raise the sugar content in saliva, promoting the development of cavities.
Led by lecturer Akito Sakanaka, the research team examined the oral health of 60 participants, including both individuals with and without diabetes. The study focused on how blood sugar influences oral health by analyzing freshly secreted saliva from the participants’ salivary glands to track the movement of glucose and other metabolites into the mouth.
The findings revealed that people with higher blood sugar levels experienced a greater transfer of glucose and fructose into their saliva. These individuals were also more likely to develop dental plaque and cavities.
Further analysis of dental plaque showed a shift in the oral microbiome. Bacteria associated with tooth decay flourished, while beneficial bacteria that help maintain oral health diminished. This bacterial imbalance led to an environment more conducive to sugar breakdown and acid production, which accelerates tooth decay.
Interestingly, the study also tracked diabetic patients during hospitalization. When their blood sugar levels were controlled, sugar concentrations in their saliva dropped, and the balance of their oral bacteria improved. Harmful bacteria decreased, while beneficial bacteria increased—changes that occurred without any dental interventions.
Sakanaka emphasized that these results suggest controlling blood sugar can significantly impact oral health, independent of dental treatment. “Our findings show that blood sugar levels directly influence tooth decay,” he said. “Next, we plan to investigate the effects of saliva sugar in healthy individuals.”