Our sense of smell does more than help us enjoy food or avoid danger—it might also give us clues about our brain health. A new study by researchers at the University of Chicago Medicine has found that people who lose their sense of smell over time may be at higher risk of memory problems and brain changes linked to Alzheimer’s disease.
This study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, suggests that a simple smell test could help detect early signs of cognitive decline before major symptoms appear.
Alzheimer’s is a serious brain condition that affects more than six million people in the United States. It causes memory loss, mood swings, and difficulty doing everyday tasks. Because there is no cure, finding ways to catch it early is very important. Early detection may help doctors slow the disease or manage it more effectively.
To better understand how smell is connected to brain health, the researchers used data from the Memory and Aging Project (MAP), a long-term study that follows older adults to learn more about aging and brain diseases. Participants in this study took smell tests each year, along with memory and thinking tests. The researchers also looked for signs of dementia over time.
They found something remarkable: people who lost their sense of smell more quickly—while they were still thinking normally—were more likely to develop signs of Alzheimer’s later. These signs included smaller areas of the brain linked to smell and memory (specifically in the gray matter), poorer thinking skills, and a higher chance of being diagnosed with dementia.
Even more striking, the risk of dementia linked to smell loss was about the same as the risk from having the APOE-e4 gene—a well-known genetic factor that increases a person’s chance of developing Alzheimer’s.
This isn’t the first time the sense of smell has been linked to brain health. In earlier studies, researchers found that older people with no sense of smell were three times more likely to die within five years than those who could smell normally. In fact, it was a stronger predictor of death than other major illnesses like heart disease or cancer.
The research team now hopes to examine actual brain tissue to confirm their findings and to test whether smell tests could be a reliable tool for doctors. They also want to include more people from different backgrounds in future studies to make sure the results apply to everyone.
This research highlights how important the sense of smell might be—not just for enjoying life, but for understanding how our brains age. If a simple smell test can spot early changes in the brain, it could become a powerful, low-cost way to identify people at risk of Alzheimer’s long before symptoms start.
If you’re interested in protecting your brain health, scientists also recommend healthy habits like following a Mediterranean diet, staying active, and getting enough sleep. Some research even shows that foods like blueberries and nutrients like vitamin D may help slow memory loss. Other studies are exploring how blood pressure problems at night may increase the risk of Alzheimer’s.
This growing body of research points to one clear message: taking care of your senses—especially your sense of smell—could also mean taking care of your brain.
If you care about Alzheimer’s disease, please read studies that bad lifestyle habits can cause Alzheimer’s disease, and strawberries can be good defence against Alzheimer’s.
For more information about brain health, please see recent studies that oral cannabis extract may help reduce Alzheimer’s symptoms, and Vitamin E may help prevent Parkinson’s disease.
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