Our sense of smell does more than help us enjoy food or detect dangers like smoke. Researchers from the University of Chicago Medicine have found that a weakening sense of smell over time may predict future memory problems and brain changes linked to Alzheimer’s disease and dementia.
Their study suggests that simple smell tests could help identify people at risk for cognitive decline before noticeable symptoms appear.
Alzheimer’s disease affects over 6 million Americans, leading to memory loss, mood changes, and difficulties with daily activities. Since early detection is key to better management, scientists are looking for new ways to spot the disease sooner.
This study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, offers a possible tool: tracking changes in a person’s ability to smell.
To conduct their research, the team analyzed data from the Memory and Aging Project (MAP), a long-term study that follows older adults to understand aging and neurodegenerative diseases. Participants took yearly tests measuring their ability to recognize specific scents, their cognitive function, and any signs of dementia.
The findings were striking. People who experienced a rapid decline in their sense of smell—while still having normal thinking ability—were more likely to show early signs of Alzheimer’s. These included smaller gray matter volume in brain regions linked to smell and memory, poorer cognitive function, and a higher risk of developing dementia later on.
The study also found that the risk from losing smell was similar to that of carrying the APOE-e4 gene, which is a well-known genetic factor for Alzheimer’s disease. This suggests that monitoring changes in smell could be just as important as genetic testing when assessing Alzheimer’s risk.
Looking ahead, the researchers plan to further confirm their findings by examining brain tissue for Alzheimer’s markers. They also hope to test smell-based screenings on a more diverse group of people to see if the results hold true across different populations.
This isn’t the first time scientists have linked the sense of smell to overall brain health. Earlier studies from the same research team found that older adults who had completely lost their ability to smell were three times more likely to die within five years—making it a stronger predictor of death than lung disease, heart failure, or cancer.
The results highlight the connection between smell and brain function, reinforcing the importance of paying attention to sensory changes as we age. If future studies confirm that smell tests can reliably predict cognitive decline, they could become a simple, non-invasive way to detect Alzheimer’s disease early—before irreversible brain damage occurs.
For those interested in protecting brain health, other studies suggest that a Mediterranean diet may help keep the brain strong, while blueberry supplements could slow cognitive decline. Additionally, research has linked vitamin D deficiency to a higher risk of Alzheimer’s and found that nighttime blood pressure issues may contribute to the disease.
By paying closer attention to changes in smell, we may gain valuable insights into our brain’s health and take earlier steps to prevent cognitive decline.
If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and extra-virgin olive oil could boost brain function.
For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and strawberries could help prevent Alzheimer’s disease
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