You’ve probably seen the news. It’s been shared on Facebook no telling how many times. If you GOOGLE you will get close to 179,000 hits that tell you about it.

Basically, the headlines tout the ability to test for Alzheimer if you open a jar of peanut butter, hold it up to your nose (a certain distance) and holding one side of your nose, see if you can smell it. Supposedly the sense of smell is one of the first things to go when you are a victim of Alzheimer’s.

This all fits into our 21st century mindset: to have quick and simple answers.

So having succumbed and sniffed the peanut butter myself, I did wonder…

What if you had a cold? What if you had an infection some time back and it left you permanently unable to smell on one side of your nose? Maybe you got hit in the nose and your deviated septum didn’t allow the odor molecules to filter up to where they were supposed to? And lastly, I wondered just how good was the science of this whole thing?

The way we get news and information scares me. Not to get on a soapbox, but you can’t believe everything you see on the internet. Even though we increasingly consider ‘trending’ and popularity as signals that whatever is being passed around has to be true.

Here are the facts about the peanut butter smell test:

  1. Our sense of smell is dependent upon the olfactory nerve and it is one of the first things to be affected by cognitive decline.
  2. Researchers from the U. Of Florida’s McKnight Brain Institute in the lab of Kenneth Heilman, measured the ability of patients who had been diagnosed with Alzheimer’s. One study with 94 patients.
  3. The current criticisms are:
    1. NPR reported that the study, at 94 patients, was “too small to be conclusive.”
    2. In 2012, a systematic review  found that while there may be “an association between decreased olfaction and AD,” “rigorously designed longitudinal cohort studies are necessary to clarify the value of olfactory identification testing in predicting the onset of AD.
    3. Ivan Oransky, global editorial director of MedPage Today, also criticized the media’s favorable coverage of the study, noting that the journal in which it was published, the Journal of the Neurological Sciences, “is ranked in the bottom third of neuroscience journals by Thomson Scientific‘s impact factor, 162 out of 252.” He also asked three other Alzheimer’s researchers–Richard Caselli, Sam Gandy, and George Bartzokis–what they thought about the proposed test, and their responses were less than enthusiastic. For example, Bartzokis said, “The principal problem with smell tests is that they are nonspecific and therefore only one small piece of the diagnostic puzzle.”
    4. In 2014, in an effort to reproduce the results,  a study was published, also in the Journal of the Neurological Sciences, which found no evidence of a left-right asymmetry in nasal function in Alzheimer’s disease patients.

Science is wonderful. News… not so much these days.