Scientists are now saying that Alzheimer’s may actually start in your nose, more specifically the area of the brain responsible for smell.
This has some experts thinking that the disease itself could be related to some type of environmental agent that ultimately enters the brain through the nose.
This theory is called the olfactory vector hypothesis.
And one of the biggest reasons this theory has gained so much ground is because the nerves associated with the sense of smell, called the olfactory nerves go directly into the brain.
In fact, this is one of the ways the polio virus entered the body during the height of the polio epidemic.
Does Alzheimer's Start In The Nose?
One major concern for health officials is that if someone were to inhale something like aluminum dust, it could be transported directly to the brain.
This happens at a rate of two millimeters per hour, which equates to about two inches per day.
And while it’s true there have been cases where people born without olfactory nerves have developed Alzheimer’s the theory does appear to have a lot of circumstantial evidence.
Regardless, one of the earliest confirmed signs of Alzheimer’s is a change is a person’s ability to smell.
These changes take place in what doctors call the preclinical phase. Meaning, prior to the onset of cognitive decline.
The fact that a loss of smell precedes cognitive decline makes it potentially one of the best ways to catch Alzheimer’s in the early stages.
For the past several years, researchers have tried to find markers of hidden brain decline within people’s ability to smell.
And typically, these tests are performed utilizing functional MRI. An expensive test with the ability to detect subtle changes in the brain due to Alzheimer’s in response to a variety of different scents.
And while this technology is impressive…
A group of researchers at the University of Florida have discovered that all you really need is a jar of peanut butter and a ruler.
The Peanut Butter Smell Test
Based on the fact that the left side of the brain processes what we smell from the left nostril and the right side of the brain processes what we smell from the right nostril, researchers set up an experiment.1
Subjects were asked to close their eyes and mouth as they breathed normally and plugged one nostril.
Researcher then took a foot-long ruler and held it at length away from the unplugged nostril.
Next, they opened a jar of peanut butter at the end of the ruler and moved it one centimeter closer with each exhale until the subject could smell the aroma.
The test was then repeated with the opposite nostril.
Here’s what they found…
In normal healthy elderly subjects, they smelled the peanut butter when it came within 18 centimeters’ or 7 inches away from their nose.
In the Alzheimer’s patient’s the right nostril was about the same…7 inches.
But in the left nostril the peanut butter had to get all the way up to two inches away before they could smell it.
And these findings were consistent in every person suspected of having Alzheimer’s disease.
The $2 Test VS a Million Dollar MRI
The difference was so great and so consistent it’s now been suggested that a cut off value be created for the diagnosis of Alzheimer’s.
And when compared to other causes of dementia these cutoff values remained consistent and specific for Alzheimer’s.
Said another way…there were no false positive’s or false negatives.
And when compared to normal healthy people the findings were 100% positive and 92% specific.
Meaning that if you did have Alzheimer’s there was a 100% chance that you’d have the left nostril discrepancy.
And if you had the discrepancy there was a 92% chance that you had Alzheimer’s which means there were some false positives…but not many!
The Only Way To Truly Diagnose Alzheimer’s
When it comes to Alzheimer’s the only true diagnosis happens after death using an autopsy. And the current medical standard of care is to use pet scans and spinal taps which are both invasive and expensive.
Researchers are now saying…The Peanut Butter Smell Test may be just as effective and a lot more practical.
So, if you’re concerned that you may have Alzheimer’s…grab a jar of peanut butter and ruler and find out.