Each Missing Tooth Increases Your Chances of Dementia and Cognitive Impairment, Study Says

Nobody really wants to lose their teeth, but few people realize the implications of such a loss above and beyond the obvious: paying dental bills, dealing with dentures, and struggling to chew food or talk the same way you did before.

But rest assured, there are other side effects to losing some or all of your teeth. Studies have shown that one of those side effects is an increased risk for cognitive impairment and dementia.

Researchers at NYU Rory Meyers College of Nursing conducted a meta-analysis of 14 longitudinal studies of tooth loss and cognitive impairment. The studies involved 34,074 adults, 4,689 of whom suffered from cognitive impairment.

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After controlling for other factors, adults who were categorized as having more tooth loss were found to be 1.48 times more likely to develop cognitive impairment and 1.28 times more likely to be diagnosed with dementia.

“Given the staggering number of people diagnosed with Alzheimer’s disease and dementia each year, and the opportunity to improve oral health across the lifespan, it’s important to gain a deeper understanding of the connection between poor oral health and cognitive decline,” said Bei Wu, Ph.D., Dean’s Professor in Global Health at NYU Rory Meyers College of Nursing and co-director of the NYU Aging Incubator, as well as the study’s senior author. “Our findings underscore the importance of maintaining good oral health and its role in helping to preserve cognitive function.”

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The researchers also used a subset of eight studies to look for a “dose-response” association between tooth loss and cognitive decline. In other words, they wanted to know if more teeth lost equated to a greater risk of cognitive decline. And, in fact, their hunches proved correct. Each additional missing tooth was associated with a 1.4 percent increased risk of cognitive impairment and 1.1 percent increased risk of being diagnosed with dementia.

“This ‘dose-response’ relationship between the number of missing teeth and risk of diminished cognitive function substantially strengthens the evidence linking tooth loss to cognitive impairment, and provides some evidence that tooth loss may predict cognitive decline,” said Xiang Qi, a doctoral candidate from NYU Meyers.

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There are several possible explanations for the link between tooth loss and cognitive decline. It’s possible that tooth loss may simply reflect socioeconomic disadvantages that put people at an increased risk of dementia. But it’s also possible that tooth loss causes gum disease, which can lead to cognitive decline. Or it may be that tooth loss causes difficulty chewing, which leads to nutritional deficiencies and changes in the brain.

The data say, however, that the risk was not significant among older adults with dentures. Adults with missing teeth but no dentures had a 23.8 percent likelihood of developing cognitive impairment compared to 16.9 percent of those who did have dentures. This suggests that getting dentures in a timely manner could protect against cognitive decline for people with significant tooth loss.

According to the CDC, roughly one in six adults over the age of 65 have lost all their teeth. There are so many great reasons to take care of your teeth, but we hope staving off dementia is high on your list!

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