The Peanut Butter Sniff Test for Alzheimer's


Have you had your peanut butter today? If so – could you smell it?

Dumb question. Right?

Well maybe yes, maybe no.

A recent study by researchers at the University of Florida came up with the peanut butter sniff test to determine if someone is in the early stages of Alzheimer's.

On first hearing this, I thought it sounded pretty ridiculous. The test consisted of testing a group of people, some with known early-stage Alzheimer's, by asking them to smell peanut butter, first with one nostril, then the other.

The patients with known Alzheimer's were not able to smell the peanut butter as soon in their left nostril as those who had no known symptoms of Alzheimer's disease. It seems that cognitive impairment is more evident in the left side of the brain than the right side, therefore the sniff test shows promise of being an early indicator of the disease.

Or so the researchers say.

I tried the test on myself – I couldn't smell the peanut butter at all! But then I can't smell much of anything. Ever since I used a certain anti-cold product several years ago I have had a significant loss of smell.

So I have to wonder what that has to say about my cognitive abilities. Maybe I am in full-blown dementia and just don't know it!

Purveyors of the test say we shouldn't try the test on ourselves, lest we send ourselves into a panic over the possibility that we are declining into dementia.

I haven't tried it on Charlie yet, but I plan to.

We all know he is suffering from a form of dementia, so I am anxious to see how good his nose is working, just to prove-disprove the test.

Well – it's time for my evening snack – toast with peanut butter.

In case a member of your family is one of those working on the peanut butter research, forgive me for my skepticism.

Marlis describes herself as a “Gramma who loves technology and has a lot to say.” She blogs about whatever catches her interest: food, books, family and more. For, she writes about the issues facing the elderly and her experiences caring for her husband, Charlie, who suffers from dementia.

View full profile

You May Also Like

Free AgingCare Guides

Get the latest care advice and articles delivered to your inbox!


I hace noticed quite a few older people no longer can smell and most do not have alzheimers. they also lose their sense of taste. my SIL also took that cold med several yrs ago(before they took it off the market) and she lost all sense of smell. her dr at the time said many used the product and lost their sense of smell.
My husband, who is a medical professional, says that the "crossover" of brain control occurs at the neck. Although the right side of the brain controls the left arm and leg, and vice versa, the left side of the brain does indeed control the left nostril. Although I have my doubts about the validity of this study, the author is correct about which side of the brain controls the left nostril.
In a very interesting article published this month (march 2014) published in the prestigeous medical Journal of Craniofacial Surgery , with the title “Lateralized Differences in Olfactory Function and Olfactory Bulb Volume Relate to Nasal Septum Deviation” we can see that up to 72% of patients with left septal deviation have lateralized nasal obstruction on olfactory bulb that leads to HYPOSMIA (partial loss of olfactory function in the obstructed nostril).
In that common cases of LEFT septal deviation with lateralized nasal obstruction, using the so called ”smell test “ someone could be misdiagnosed as having AD or some dementia . while only havING a left septal deviation.


“ One of the most common reasons for partial nasal obstruction is nasal septal deviation .
The effect of a partial lateralized nasal obstruction on olfactory bulb volume remains unclear.
Thus, the aim of this study was to investigate the side differences in olfactory function and obstruction on olfactory bulb in patients with serious nasal septal deviation.
Sixty-five volunteers were included: 22 patients with serious RIGHT obstruction on olfactory bulb and 43 patients with LEFT OBSTRUCTION ON OLFACTORY BULB.
The patients’ mean AGE WAS 22 YEARS OLD.
All participants received volumetric magnetic resonance imaging scans (MRI) of the entire brain and detailed lateralized olfactory tests.
The majority of the patients exhibited an overall decreased olfactory function (as judged for the better nostril: functional ANOSMIA (total loss of olfactory function) in 3% of patients, HYPOSMIA (partial loss of olfactory function in 72% of the patients, NORMOSMIA (normal olfactory function) in 25% of the patients , which seems to be mostly due to the OVERALL SEVERE CHANGES in nasal anatomy.
As expected, olfactory function was significantly lower at the NARROWER SIDE as indicated for odor thresholds, odor discrimination, and odor identification (P ≤ 0.005).
When correlating relative scores and volumes (wider minus narrower side), a significantly positive correlation between the relative measures emerged for OBSTRUCTION ON OLFACTORY BULB volume and odor identification, odor discrimination, and odor thresholds.

(abstract pasted from the Journal of Craniofacial Surgery-March 2014-Vol. 25 - Issue 2: p 359-362)