Tooth loss is a risk factor for cognitive impairment and dementia — and with each tooth lost, the risk of cognitive decline grows, according to a new analysis led by researchers at NYU Rory Meyers College of Nursing and published in JAMDA: The Journal of Post-Acute and Long-Term Care Medicine. However, this risk was not significant among older adults with dentures, suggesting that timely treatment with dentures may protect against cognitive decline.-Science Daily
According to the Centers for Disease Control and Prevention, around one in every six people aged 65 and older has lost all of their teeth at some point. According to previous study, tooth loss is associated with a decline in mental performance, with researchers proposing a variety of potential reasons for this association. Because missing teeth make it difficult to chew properly, they may lead to nutritional deficits and cognitive abnormalities. A increasing body of evidence also suggests a link between gum disease, which is a major cause of tooth loss, and cognitive impairment, according to the researchers. Apart from that, dental decay may be an early sign of long-term socioeconomic difficulties, which are also risk factors for cognitive impairment. Given the staggering number of people diagnosed with Alzheimer’s disease and dementia each year, as well as the opportunity to improve oral health across the lifespan, it is critical to gain a better understanding of the relationship between poor oral health and cognitive decline, said Bei Wu, PhD, Dean’s Professor in Global Health at NYU Rory Meyers College of Nursing and co-director of the NYU Aging In Research Center.
Using longitudinal investigations of tooth loss and cognitive impairment, Wu and her colleagues performed a meta-analysis of their findings. There were a total of 34,074 individuals in the 14 studies that were included in their analysis, as well as 4,689 instances of patients with impaired cognitive function. Even after accounting for other variables, the researchers discovered that individuals who had greater tooth loss had a 1.48 times higher chance of having cognitive impairment and a 1.28 times higher risk of being diagnosed with dementia. The researchers discovered that adults who had lost teeth were more likely to have cognitive impairment if they did not have dentures (23.8 percent) compared to those who did have dentures (16.9 percent); however, a subsequent analysis revealed that the association between tooth loss and cognitive impairment was not significant when participants were wearing dentures. An analysis of a subset of eight studies was also carried out by the researchers in order to determine whether there was a “dose-response” relationship between tooth loss and cognitive impairment — that is, whether having a greater number of missing teeth was associated with a greater risk of cognitive decline.
According to their research, each extra missing tooth was linked with a 1.4 percent higher chance of cognitive impairment and a 1.1 percent increased risk of being diagnosed with dementia, respectively. In a statement, Xiang Qi, a doctoral candidate at NYU Meyers, said, “This ‘dose-response’ relationship between the number of missing teeth and the 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.” In the words of Wu, “Our results highlight the significance of maintaining excellent dental health and the role it plays in helping to retain cognitive functioning.”