Odor Identification Tests Can Identify Patients Vulnerable to Developing Alzheimer’s Disease

Researchers now have even more evidence backing up the theory that reduced sense of smell is an indicator of the early stages of dementia. The findings may allow scientists to create simple tests for identifying patients at high risk of developing Alzheimer’s disease. The details are in a paper that was just published in the Journal of Alzheimer’s Disease.

Alzheimer’s is a serious age-related disease, typically affecting patients 65 years and older, in which the connections between brain cells begin to die. The disease is progressive and eventually results in severe memory loss, disorientation, and impaired mental processes. There is no cure but therapy and medication can help the patient cope with symptoms. Although the disease is irreversible, early identification can make treatments more effective. Studying people who are vulnerable to the disease but are not yet showing symptoms could also be valuable to research.

A team of scientists designed an experiment to determine if “sniff tests” could be used to identify patients in the earliest stages of Alzheimer’s disease. Loss of smell is often an early symptom of dementia. The team used a test called Sniffin’ Sticks Odor Identification Test. They tested 728 individuals and the participants had to identify 16 different scents. Some of the participants were already suffering from dementia or were in the early stages of Alzheimer’s while others were completely healthy. The participants were also given a cognitive test called the Montreal Cognitive Assessment, currently used to identify patients in the earliest stages of dementia.

The research team found that while both the sniff test and cognitive test could help identify patients with early signs of Alzheimer’s, the sniff test correctly identified more patients. The team determined that odor identification tests could be more useful to doctors than current cognitive assessments. The only problem is the length of the sniff test—it can take up to 8 minutes for a patient to complete it. The research team is currently working to develop a shortened and more practical version of the sniff test. The new test will take about 3 minutes and may be useful to doctors trying to identify patients at risk of developing dementia.


Quarmley et al. Odor Identification Screening Improves Diagnostic Classification in Incipient Alzheimer’s Disease. Journal of Alzheimer’s Disease (2016).

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