One tablespoon of peanut butter and a ruler can help confirm early Alzheimer’s disease diagnoses, according to University of Florida researchers.
Jennifer Stamps, a UF graduate student at the UF McKnight Brain Institute Center for Smell and Taste, said she got the idea to use peanut butter to test smell sensitivity when working with Dr. Kenneth Heilman, a professor in UF College of Medicine’s department of neurology.
While shadowing in Heilman’s clinic, Stamps said she saw that patients suffering from cognitive deficiencies were not being tested for their sense of smell, which is one of the first things affected during a cognitive decline, according to a press release.
For people diagnosed with Alzheimer’s disease, the part of the temporal lobe evolved from the smell system is one of the first parts of the brain that degenerates. It is also the same portion of the brain that takes part in forming new memories.
Stamps said she decided to use peanut butter for her test because it is easy to access and is a “pure odorant” detected only by the olfactory nerve.
“Dr. Heilman said, ‘If you can come up with something quick and inexpensive, we can do it,’” Stamps said.
A clinician administered the test to patients using about one tablespoon of peanut butter and a metric ruler to conduct the study.
After the patients closed their eyes and mouth and blocked one of their nostrils, the clinician held the ruler next to the open nostril as the patient breathed normally.
The clinician moved the peanut butter, which was held in a small plastic cup, up the ruler one centimeter at a time toward one nostril until the patients could detect the smell.
The distance was recorded and the same steps were taken with the patients’ second nostril.
The study showed a large difference between the right and left nostrils' ability to detect the odor for patients in the early stages of Alzheimer’s disease.
In most cases, the left nostril was more impaired and did not detect the odor until the peanut butter was about 10 centimeters closer to the nose.
Patients suffering from other types of dementia had different results. The patients either had no difference in odor detection between nostrils or had right nostrils that were worse at detecting the peanut butter odor.
Stamps and Heilman said the peanut butter test could be helpful for clinics that don’t have access to the necessities to perform more elaborate tests.
UF Health will use the peanut butter test, as well as other clinical tests, to help determine neurological functioning in patients with memory disorders.
“At the moment, we can use this test to confirm diagnosis,” Stamps said. “But we plan to study patients with mild cognitive impairment to see if this test might be used to predict which patients are going to get Alzheimer’s disease.”