How A Peanut Butter Test May Detect Alzheimer’s

Alzheimer’s is an extremely terrible and debilitating illness that impacts many people. Sadly, Alzheimer’s also takes its toll on the friends and family of the person diagnosed with it, leaving everybody in an extremely tough position. Adjusting to a life with Alzheimer’s is no easy task, so being able to catch it early on is invaluable. Recently, a new method has been developed to catch early stage Alzheimer’s and it’s extremely simple, as well as inexpensive. All it takes is some good ol’ peanut butter.

peanut butter

Peanut butter. Creamy or crunchy – and oh, so spreadable – but not exactly your first thought as a game changer in Alzheimer’s research.

But it may well be, according to researchers at the University of Florida who conducted the peanut butter smell test hoping to find a relationship between loss of smell and the detection of early-stage Alzheimer’s.

They were able to use the test to confirm an Alzheimer’s diagnosis. But they would like to be able to predict which patients are going to get Alzheimer’s disease.

Researchers at the University of Florida’s McKnight Brain Institute Center for Smell and Taste found that by placing a tablespoon of peanut butter on a ruler, they could identify early stages of Alzheimer’s based on studying the subjects’ ability to detect its odor at different distances.


This is because the ability to smell is linked to the first cranial nerve and its impediment is one of the first signs of cognitive decline. The researcher responsible for choosing peanut butter, graduate student Jennifer Stamps, said that the nutty spread was an ideal pick because it is a “pure odorant,” which means it is solely detected by the olfactory nerve (the collection of sensory receptors in your sinuses responsible for picking up on odors). Plus, it’s inexpensive and easy to access.

Patients who participated were told to close their eyes, block one nostril, and breath normally while a clinician slowly moved the peanut butter up the ruler one centimeter at a time until the patient was able to detect the odor. The distance was recorded and then repeated again using the other nostril—after a 90-second break.

What researchers found is peculiar. The sense of smell in the left nostril specifically was severely impaired in the tested group who already had early-stage Alzheimer’s.

In order for people to smell the peanut butter through their left nostril, the container had to be an average of 10 centimeters closer to the nose than for the right nostril.

“This is a significant part of this study,” says Dylan Wint, MD, who works in the Cleveland Clinic Lou Ruvo Center for Brain Health.

“There are a lot of studies about Alzheimer-related brain shrinkage starting on the left side of the brain, which is where the temporal lobe degenerates first.”