Tooth Loss and Diabetes Increase Dementia Risk, Expert Explains Why

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Tooth loss, diabetes, and Alzheimer’s disease or dementia may seem like unrelated health issues. However, a growing body of evidence suggests that there may be a strong association between these conditions.

A new study published in the Journal of Dental Research supports this link, indicating that individuals with tooth loss and diabetes may be at increased risk for Alzheimer’s disease or dementia.

Tooth Loss and Diabetes Linked to Dementia

Researchers used data from the University of Michigan’s Health and Retirement Study. They included 9,948 older adults from 65 years to 85 and older, and analyzed 12 years of data (2006–2018) to observe cognitive changes over time.

At the start of the study, the participants completed a dental examination to determine how many remaining teeth they had. They also underwent blood tests to check for diabetes.

Participants were then monitored for signs of Alzheimer’s disease or dementia during the study period, as well as asked questions about tooth loss, diabetes, and other health and demographic factors.

The results of the study showed that individuals with tooth loss and diabetes were nearly three times more likely to develop cognitive disorders compared to those with neither condition. Adults aged 65 to 74 with diabetes and complete tooth loss had the fastest rate of cognitive decline.

While the study also found a slightly increased risk for those with diabetes or tooth loss alone, the association was not as strong.

Diabetes and Oral Health

The complications of diabetes can affect dental health.

“Dry mouth” is more common in people with diabetes, which could be a result of aging or medications, or the disease itself. The lack of saliva means food debris, sugar, acid, and bacteria aren’t washed away as easily. This can lead to gum disease.

A 2017 study from the British Medical Journal found evidence that a form of severe gum disease, called periodontitis, is an early sign of Type 2 diabetes. They also found that people with mild to moderate gum disease also had more relatives with diabetes than those with no, or severe, gum disease.

The study also found body weight was much higher in those with severe gum disease, with an average BMI of 27 or higher.

So why do tooth loss and diabetes increase Alzheimer’s risk?

3 Possible Reasons: Experts

1. Other Health Problems

“People with diabetes and poor oral health often have other health problems, such as high blood pressure, high cholesterol levels, and cardiovascular disease, which are also risk factors for dementia,” lead study author Bei Wu, who holds a doctorate in gerontology and is vice dean for research at NYU Rory Meyers College of Nursing and co-director of the NYU Aging Incubator, told The Epoch Times.

2. Inflammation

Another theory is that inflammation may play a role.

A 2019 study followed 12,336 people with an average age of 57 for roughly 20 years to find participants with the highest level of chronic inflammation experienced a nearly 8 percent steeper decline in cognitive ability compared with those who had the lowest inflammation levels.

“Chronic inflammation is a common feature of diabetes and poor oral health (like periodontitis), and it has been linked to increased risk of cognitive decline and dementia,” said Wu.

“In the United States, more than 75 percent of edentulous [lacking teeth] older adults wear dentures,” the Journal of Dental Research study authors wrote. “And it is known that biofilm that forms on dentures can house bacteria, yeasts, and fungus that result in inflammatory response in the oral tissues.”

Additionally, poor oral health and hygiene are linked to an increased risk of infections that can cause inflammation and further contribute to cognitive impairment.

3. Dietary Intake

Wu also pointed out the role diet plays. “Poor oral health affects dietary intake,” said Wu. “Healthy eating is also beneficial for cognitive health.”

A recent review of studies found that older individuals with oral health problems had poorer diets and consumed fewer nutrient-rich foods. They also had a low intake of fruits and vegetables, vitamin C, and vitamin E, and higher consumption of processed foods.

“Findings from this study provide some practical implications for maintaining cognitive health,” said Wu.

She noted that her study highlights the importance of regular dental visits, having good oral hygiene practice, adherence to diabetes treatment and self-care to control blood sugar levels, and cognitive screenings in primary care settings.

“Poor oral health, diabetes, and cognitive decline are all connected, and we’re beginning to understand how they may influence and exacerbate one another,” said Wu.