If you can smell peanut butter, you may not have Alzheimer’s

Question

In the article titled "If you can smell this, you may not have Alzheimer's" writer Dan Nosowitz, freelance writer and editor of Popular Science claims that a low-cost and noninvasive way of finding out if you have Alzheimer's is if you can't smell the scent of peanut butter. He referenced one experiment taken by researchers at the University of Florida which essentially said that if you are cognitively declining, one of the first things to be affected is the first cranial nerve that is associated with smell. Upon further research, it is true that the sense of smell is a common thing to lose if diagnosed with Alzheimer's. So based on the study conducted by the University of Florida, the claim appears to be true yet can be misleading if taken seriously because of its clickbaity nature. In a study done in 2014 by the University of Pennsylvania as a follow up to the one taken by the University of Florida, they were unable to produce the same results and released the statement "Intriguing results don't always hold true across all study populations" (Dr. Wint 2014).  All in all, although Nosowitz's claim is true in some implications, it may not be entirely true in others.

Answer 1

The article cited points to the University of Florida's research center for Smell and Taste Studies as it's leading argument that this claim is true. However, in further research and a look at the National Library of Medicine's test on this diagnostic and its results came back inconclusive with a failure to replicate UF's results. Studies performed by scientists such as Richard L. Doty, Inna Chung, and many others prove that there is no meaningful left vs. right nose side difference in patients with AD or probable for AD in their ability to detect peanut butter odor. Here's an article that helps explain these results in detail as well as the original University of Florida report on this claim.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4167392/#:~:text=A%20widely%20publicized%20study%20by,of%20Alzheimer's%20disease%20(AD).

https://ufhealth.org/news/2013/uf-researchers-find-peanut-butter-test-can-help-diagnose-alzheimer-s-disease

Comments

Your comment includes sources to trusted and peer reviewed studies, which is incredibly important, to further expand on your point it seems as though the original article completely missed the results of the study, even claiming that it could be a "early warning system for those with Alzheimer’s" which is harmful and damaging. There is currently no universal way to predict if somone will have Alzheimers, and the only indiactors could be different across population groups, as stated in this article: https://www.nia.nih.gov/health/alzheimers-causes-and-risk-factors/alzheimers-disease-genetics-fact-sheet#:~:text=Each%20person%20inherits%20two%20APOE,best%20for%20that%20particular%20group.

Answer 2

Although the source provides good reasoning and evidence to support their claim about smelling peanut butter can tell you if you have Alzheimers or not, this is a topic that needs deeper examination because there could be other factors that could lead to you not being able to smell. In an attempt for further examination, there was a follow up study conducted by the University of Pennsylvania in 2014 to attempt to replicate the University of Florida's study. They found that they were unable to replicate the study and determine if the ability to smell peanut butter can be an early sign of Alzheimers. Because no one has been able to replicate the study, we can't be sure that this is a real remedy or not. 

https://health.clevelandclinic.org/peanut-butter-test-may-detect-alzheimers

Answer 3

The claim is based on a study done at the University of Florida in 2013 but the investigators that published their study said that follow-up research would be required. According to an article published four years ago by the Cleveland Clinic (a monthly indexed, national peer-reviewed medical journal): a 2014 study at the University of Pennsylvania "could not replicate their results". The second study tested 15 patients with Alzheimer’s and found no difference in the ability to smell peanut butter in their different nostrils. Though both studies are around ten years old and could be worth revisiting for now this is false.

https://health.clevelandclinic.org/peanut-butter-test-may-detect-alzheimers