[Updated May 10, 2018]
A decade or more before memory-related symptoms of Alzheimer’s disease (AD) appear, disordered processes are underway in the brain – including changes that may affect sense of smell. In a study published in Annals of Neurology, researchers gave 183 community-living older adults cognitive tests to assess brain function, followed by tests of their ability to recognize and remember familiar odors, such as leather, menthol and grape.
People who had normal cognitive test results did significantly better on combined tests of identifying and remembering smells compared to people with mild cognitive impairment or AD. People who did worse on the tests than expected were more likely to carry gene variants linked to AD risk or show changes in an area of the brain associated with early AD. Although promising, further study is needed. Note that poor sense of smell doesn’t necessarily point to AD.
To Learn More: Annals of Neurology, December 2016