It has been known for at least 20 years that Alzheimer's Disease damages your ability to smell early on in the course of the disease. Ten years ago, a list of 10 scents were identified as significant indicators that a person would end up with Alzheimer's if the person was unable to smell them. This month, a new test has been made known to the public in which peanut butter helps to confirm an Alzheimer's diagnosis.
Peanut butter was chosen because it is a pure odorant meaning that it triggers just the olfactory bulb and not other closely associated nerves. It is also cheap, easily identified and readily available. Peanut butter has a unique scent while others may be misidentified as a related scent. For example, you might think a lemon was a lime.
The test checks to see if a person can smell the peanut butter at the same distance through their left nostril as they can through their right nostril. That's it. Pretty simple. The findings indicate that if you cannot smell the peanut butter through your left nostril or have to be much closer to it than when you smell it with your right nostril, you may have Alzheimer's. If you can smell it more easily with your left than your right or if you smell it equally well in both, then you may not need to worry about Alzheimer's. You may have something else going on; just not Alzheimer's.
I've been reading about the test and all the excitement over it for a week now and, against the standard Mythbuster type warnings of "Do not try what you're about to see at home", I tried it. (Did you honestly expect anything different from me? I've got Theo Gray's Mad Science: Experiments You Can Do at Home - But Probably Shouldn't sitting on my dining table right now, after all.)
I'm happy to report that as of this writing, I can smell peanut butter a mile a way. Take a lid off and the smell of it fills a room for me. Then again, I'm not the target demographic for the test and just did it out of curiosity. Before you ask... No. I'm not planning to ask Lyn to participate in the test. She'll well beyond the early stages of Alzheimer's and I'm not sure she can understand what I would be asking of her.