If you notice a decline in your sense of smell, there may be reason for concern. Olfactory function naturally decreases with age, and its loss can also be an early indicator of neurodegenerative disorders. New research links a declining sense of smell to a faster accumulation of Alzheimer’s-related brain changes observed in brain scans.
A reduced ability to smell may signal upcoming memory issues and a higher risk of Alzheimer’s disease. The research strengthens the evidence that loss of smell is an early indicator of Alzheimer’s-related cognitive decline and the buildup of harmful proteins, such as amyloid and tau in the brain.
The study included 364 participants from the Baltimore Longitudinal Study of Aging, all cognitively normal at the beginning of the testing. For the next 2.5 years, they underwent baseline cognitive tests, odor identification assessments, and brain imaging scans.
To investigate the link between olfactory function and brain volume, researchers compared odor identification scores with brain MRI scans. Participants who developed cognitive impairment or dementia exhibited lower odor identification scores compared to those who remained cognitively normal.
The study results found that 5% of the monitored participants were diagnosed with mild memory impairment, a stage characterized by declining cognition that may progress to Alzheimer’s disease.
The brain scans showed that participants with a declining sense of smell exhibited brain changes characteristic of Alzheimer’s disease. As their olfactory function decreased, the presence of plaques and tangles increased in brain regions essential for learning and smell processing.
The study reveals a significant link between reduced smell sensitivity and an increased risk of developing mild cognitive impairment and other dementia types. Researchers plan to further investigate whether olfactory decline can predict other neurodegenerative changes associated with dementia.
To view the original scientific study click below:
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