Tooth loss linked to faster cognitive decline in Hispanic older adults

Older Hispanic adults who have lost all their natural teeth may face faster declines in cognitive function compared to those who still have their teeth, according to a new study published in Research on Aging. The findings also suggest that while both Hispanic and Black adults tend to begin with lower cognitive scores in late life, their rates of decline may be slower—unless tooth loss is a factor.

The researchers conducted the study to better understand how tooth loss, a condition known as edentulism, might influence age-related cognitive decline, particularly across different racial and ethnic groups. Prior research has shown that people of color in the United States are more likely to have poorer oral health, and that they often experience disparities in cognitive aging.

To investigate these questions, the research team analyzed data from the Health and Retirement Study, a long-running, nationally representative survey of adults aged 51 and older in the United States. The data included nearly 190,000 observations from over 23,000 people collected between 2006 and 2020. Roughly two-thirds of the participants identified as non-Hispanic White, about one-fifth were non-Hispanic Black, and 14% were Hispanic. Just over 13% of the total sample were edentulous at the start of the study.

Each participant completed multiple assessments over the years to track their cognitive performance. These assessments measured short-term memory, attention, and mental processing using a 27-point scale. Higher scores indicated better cognitive functioning. The researchers also gathered information on whether participants had lost all their teeth, as well as other factors like education, income, health status, and lifestyle behaviors such as smoking and physical activity.

At the beginning of the study, non-Hispanic White participants had the highest average cognitive scores, while Hispanic and Black participants scored lower on average. Specifically, Black and Hispanic individuals started with scores roughly two to four points lower than White individuals. People without teeth also had lower baseline scores compared to those who still had their natural teeth.

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Over time, cognitive scores tended to decline with age across the sample. But the rate of this decline varied by race and ethnicity. On average, non-Hispanic White participants experienced more rapid declines in cognitive function than Black and Hispanic participants. This pattern may reflect what researchers call a “floor effect,” meaning those who start at lower levels have less room to decline.

When the researchers focused on tooth loss, they found that edentulism was linked to faster cognitive decline across all groups. However, this effect was most apparent among Hispanic participants. For this group, having no natural teeth weakened the protective pattern of slower cognitive decline.

Hispanic participants without teeth declined about 0.03 points faster per year compared to their dentate Hispanic peers. This may sound small, but over a decade or more, the effect could be meaningful. Notably, edentulism did not appear to significantly speed up cognitive decline for Black participants in the same way.

The researchers propose several reasons why tooth loss might accelerate cognitive aging. People without teeth often have trouble chewing, which can reduce blood flow to parts of the brain involved in memory and thinking. Tooth loss can also be a sign of long-term gum disease, which increases inflammation throughout the body—a factor linked to brain aging. Another possibility is that people with no teeth may avoid certain healthy foods, leading to poor nutrition, which can also affect cognitive health.

These oral health challenges are not distributed evenly across the population. Previous studies have shown that Black and Hispanic Americans are more likely to suffer from complete tooth loss due to unequal access to dental care, lower income, and other social disadvantages. In the current study, Hispanic participants had the lowest rates of edentulism, but they also had the lowest levels of education and household wealth, on average.

Interestingly, while edentulism accelerated cognitive decline among Hispanics, it did not have the same effect in Black participants. The authors suggest a few possible explanations. Black participants in the study were more likely to be married or partnered, which may offer social support that buffers the impact of tooth loss. It’s also possible that lifelong exposure to poor oral health among Black adults may reduce the added burden of complete tooth loss, though this idea would need further study.

Another important finding was that regular dental visits were linked to better cognitive outcomes. People who saw a dentist in the past two years scored higher on cognitive tests than those who had not. This finding points to the potential benefits of preventive dental care—not just for oral health but possibly for brain health as well.

The study has some limitations. It relied on self-reported data about tooth loss, which may not be as accurate as clinical assessments. The researchers also used a brief cognitive screening tool rather than a full battery of cognitive tests. While the large, nationally representative sample is a strength, the study only included three racial and ethnic groups, which limits how broadly the findings can be applied. Finally, because the study is observational, it cannot prove that tooth loss causes cognitive decline—it can only show that the two are linked.

Even with these caveats, the study adds to a growing body of evidence suggesting that oral health and brain health are deeply connected. It also raises important questions about how health disparities in one domain—such as dentistry—can spill over into others. The findings suggest that improving access to dental care, especially for underserved communities, could be one way to help reduce inequalities in cognitive aging.

Future research should explore the biological and social mechanisms that explain why tooth loss affects some groups more than others. It may also be worthwhile to examine whether restoring missing teeth with dentures or implants can slow down cognitive decline. In the meantime, the authors recommend that healthcare providers include oral health as part of regular screenings for older adults, especially those at greater risk of tooth loss and cognitive impairment.

The study, “Trajectory of Cognitive Decline Across Different Racial/Ethnic Groups: The Role of Edentulism,” was authored by Ruotong Liu, Xiang Qi, Huabin Luo, and Bei Wu.