Our sense of smell does more than alert us to potential dangers or pleasant aromas—it might also serve as a window into brain health.
Researchers at the University of Chicago Medicine have discovered that a decline in the ability to smell over time could predict cognitive decline and brain changes associated with Alzheimer’s disease and dementia. This finding offers a new possibility for earlier detection and better management of these conditions.
Alzheimer’s disease, which affects over 6 million Americans, is marked by memory loss, mood changes, and difficulties in daily tasks. Early detection is critical for slowing its progression and improving quality of life.
The research team’s study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, suggests that simple smell tests might help identify early signs of cognitive impairment.
The study relied on data from the Memory and Aging Project (MAP), a long-term investigation into chronic conditions and neurodegenerative diseases. Participants in this study were tested annually for their ability to recognize certain smells, along with assessments of their cognitive function and dementia symptoms.
The researchers uncovered a striking pattern: people who experienced a rapid decline in their sense of smell during periods of normal cognition were more likely to develop signs of Alzheimer’s disease.
These signs included reduced gray matter in brain regions linked to smell and memory, worsened cognitive abilities, and an increased risk of dementia. Surprisingly, the risk from smell loss was comparable to that associated with carrying the APOE-e4 gene, a well-known genetic factor for Alzheimer’s.
This connection between smell and brain health emphasizes the importance of further research. The team plans to examine brain tissue for specific markers of Alzheimer’s and test the reliability of smell tests as a screening tool for early dementia detection.
They also aim to study how these findings apply to more diverse populations to see if underrepresented groups are similarly affected.
The significance of the sense of smell in overall health has been a key focus for the researchers. Previous studies revealed that older adults who lost their sense of smell were three times more likely to die within five years—a stronger predictor of mortality than conditions like lung disease, heart failure, or cancer.
For those interested in protecting brain health, adopting lifestyle changes may also help. Studies suggest that following a Mediterranean diet, rich in fruits, vegetables, whole grains, and healthy fats, could support cognitive function. Blueberry supplements have also been linked to preventing cognitive decline.
Additionally, vitamin D deficiency and nighttime blood pressure problems have been associated with a higher risk of Alzheimer’s and vascular dementia.
The findings from this study open a promising avenue for using smell as a potential tool for early detection of Alzheimer’s and related conditions. By identifying risks earlier, patients and doctors can take steps to manage the disease more effectively, potentially improving outcomes and quality of life.
If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and higher magnesium intake could help benefit brain health.
For more information about brain health, please see recent studies about Vitamin B9 deficiency linked to higher dementia risk, and results showing flavonoid-rich foods could improve survival in Parkinson’s disease.
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