• Posted July 18, 2025

Poor Oral Health Potentially Linked To Chronic Health Problems

Poor dental health could be a harbinger of chronic illnesses like type 2 diabetes and heart disease, a new study warns.

People with missing teeth, coated tongues and other signs of poor oral health also were more likely to have elevated blood sugar, high cholesterol and diminished kidney function, researchers reported recently in the Journal of Oral Rehabilitation.

“Overall, our results suggest that a decline in oral function can be a risk factor for lifestyle-related diseases. Thus, maintaining good oral health is the first step in maintaining overall health,” researcher Dr. Mitsuyoshi Yoshida, chair of dentistry and oral-maxillofacial surgery at Fujita Health University in Japan, said in a news release.

For the study, researchers tracked the health of 118 men and women 50 or older. They compared results of dental exams in 2021 with those from physical exams in 2021 and 2023.

The dental exams looked at level of tongue coating, dryness of mouth, number of remaining functional teeth, maximum tongue pressure, ability to chew and swallow, and oral diadochokinesis (OD) – a test measuring the speed and accuracy with which a person can repeat syllables.

Results show that:

• People with high blood sugar had significantly lower numbers of remaining teeth and worse OD scores.

• People with high cholesterol had coated tongues and worse OD scores.

• People with diminished kidney function had coated tongues, fewer remaining teeth and worse OD scores.

“The results of this study indicate that a decline in oral function may increase the risk of lifestyle-related diseases and facilitate the progression of frailty,” researchers wrote in their paper.

Oral health could be linked to these chronic illnesses through unhealthy bacteria growing in a poorly tended mouth, or by the inflammation found in diseased gums and teeth, researchers speculated.

Researchers noted that this was an observational study and could not draw a direct cause-and-effect link between dental health and chronic disease.

The association might also run the other way, with chronic diseases increasing risk of poor oral health rather than the other way around.

The research team said larger studies involving more people are needed to better understand how dental health and chronic diseases are related.

In the meantime, they argue it couldn’t hurt to include tooth counts and OD tests as part of a person’s regular check-up, since these might be indicators of hidden disease.

“Implementing oral function tests during health check-ups might lead to better health promotion,” the researchers concluded.

More information

The Cleveland Clinic has more on how oral health relates to overall health.

SOURCES: Fujita Health University, news release, July 10, 2025; Journal of Oral Rehabilitation, April 17, 2025