Researchers at the University of Osaka have found that sustained high blood sugar levels raise the risk of tooth decay as sugars transfer from blood to saliva. In a survey of around 60 diabetic and nondiabetic individuals, higher blood sugar was linked to increased glucose and fructose in saliva, along with greater tooth decay and plaque.
A research team from the University of Osaka has determined that sustained high blood sugar levels, caused by diabetes and other factors, elevate the risk of tooth decay because sugars in the blood transfer to saliva. Led by lecturer Akito Sakanaka, the team surveyed around 60 diabetic and nondiabetic individuals to explore blood sugar's impact on oral health. They collected glandular saliva—freshly secreted from salivary glands—to analyze the transfer of sugars and blood-derived metabolites.
The findings indicated that individuals with higher blood sugar levels experienced greater transfers of glucose and fructose from blood to saliva, leading to increased tooth decay and dental plaque. An examination of dental plaque revealed a rise in bacteria that cause decay and a decline in those that support oral health. The oral microbiome became more inclined to break down sugars and produce acid, facilitating tooth erosion.
In contrast, when diabetic patients were hospitalized and their blood sugar was controlled, sugar levels in saliva decreased, and the mouth's bacterial balance improved, with fewer decay-associated bacteria and more beneficial ones. This improvement occurred without any dental treatment, suggesting that effective blood sugar management directly enhanced oral health.
"We've found that blood sugar levels affect tooth decay," Sakanaka said. "We want to investigate the amount of sugar supplied through saliva and the effects on healthy people."
The study was published in the international journal Microbiome late last year.
