A toothache or painful gums may feel like a local problem, but a new study led by NYU Shanghai Provost and Distinguished Global Professor of Public Health Bei Wu suggests that oral health may be connected to the risk of developing dementia later in life, especially for people who carry a higher genetic risk.
Published in GeroScience, the study found that several indicators of poor oral health, including painful gums, toothache, denture use, and a greater number of oral health conditions, were associated with a higher risk of dementia. The study is among the first to examine multiple oral health indicators in conjunction with two measures of genetic risk, a polygenic risk score and APOE ε4 status. Dementia risk was highest among people who had both poor oral health and elevated genetic susceptibility, pointing to the mouth as a possible window into brain health and healthy aging.
“Dementia is a complex condition influenced by age, genetics, vascular health, lifestyle, and broader aging-related processes,” explained Wu. “At the same time, oral health is increasingly recognized as an important component of overall health, but it is still often overlooked in conversations about brain aging and dementia prevention.” The team wanted to know whether oral health problems were linked to later dementia risk, and whether that link was stronger among people with higher genetic risk.
The study analyzed data from the UK Biobank, a large population-based cohort of more than 500,000 adults in England, Scotland, and Wales. The final sample included 364,557 participants who were free of dementia at baseline and had complete oral health and genetic data. Over a median follow-up of 13.64 years, 7,553 participants developed dementia, including 3,277 with Alzheimer’s disease and 1,578 with vascular dementia.
“Using data from the UK Biobank allowed us to follow a large cohort of adults over time and examine how oral health and genetic susceptibility jointly relate to dementia risk,” said Yunrui Liu, a postdoctoral associate at NYU and first author of the study. “We looked at self-reported indicators such as painful gums, bleeding gums, loose teeth, toothache, and denture use, as well as the total number of oral health conditions each participant reported.”
Genetic susceptibility was measured through an Alzheimer’s disease polygenic risk score, which reflects the combined contribution of many genetic variants, and APOE ε4 carrier status, one of the strongest known genetic risk factors for Alzheimer’s disease and dementia.
The results showed a clear pattern. Painful gums, denture use, and a greater number of oral health conditions were associated with higher risks of all-cause dementia, Alzheimer’s disease, and vascular dementia. Toothaches were associated with all-cause dementia and Alzheimer’s disease, but not clearly with vascular dementia. These associations remained even after the researchers accounted for age, lifestyle, socioeconomic factors, and other health conditions.
The study also calls for careful interpretation of the impact of denture use. “Because the UK Biobank does not include detailed measures such as the number of missing teeth or remaining teeth, denture use was treated as a proxy for severe or irreversible tooth loss relative to participants who reported no oral health problems,” explained Xiang Qi, assistant professor at NYU Rory Meyers College of Nursing and co-author of the study. “It should not be read as evidence that dentures themselves increase dementia risk.”
Genetic susceptibility was by far the strongest predictor of dementia in the study, with the highest-risk genetic groups carrying several times the risk of those at lowest genetic risk. When oral health was considered together with genetic risk, those with both poor oral health and elevated genetic risk stood out as the highest-risk group, even though the extra risk associated with the combination was modest. The pattern suggests that oral health may be relevant not only on its own, but also as part of broader dementia risk assessment.
“While genetic risk cannot be rewritten, daily behaviors and proactive healthcare can be controlled,” Wu said. “Taking care of your oral health is a highly practical and accessible way to actively participate in protecting your brain.”
The research team includes collaborators from NYU Shanghai, NYU Rory Meyers College of Nursing, and East Carolina University.