You may have heard that if a loved one has a failing sense of smell, he or she is headed for Alzheimer's disease. Not necessarily true, according to a new report in the journal The Laryngoscope.
Dr. Mehmet Oz, for example, offers an Alzheimer's smell test on his website, probably based on earlier research suggesting a link between a difficulty in identifying scents like banana and cinnamon to the presence of Alzheimer's lesions in the brain. Clinicians have sometimes used smell tests as part of a clinical assessment, although they're not among the key tests used to diagnose Alzheimer's.
The new study, conducted by Robert Wood Johnson Foundation Clinical Scholars at the University of Michigan and the VA Center for Clinical Management Research, is the first systematic review of the quantity and quality of so-called olfactory identification tests as prognostic tools for Alzheimer's. The authors reviewed nearly 1,200 articles dating back to 1984.
Although the team found evidence that loss of smell is associated with Alzheimer's, there's not enough proof to conclude that loss of smell is a predictor for developing the disease, reports Medical News Today. The researchers note that several different medical problems are also associated with loss of smell. There are also several other possible explanations for an association between smell changes and dementia, such as age or dehydration.
"A nonspecific association between poor smell function and Alzheimer's dementia is not the same as actually being able to use a smell test to predict Alzheimer's," says Gordon Sun, a general otolaryngologist at the University of Michigan. "This study helps set the record straight about where the evidence currently stands."
He adds: "Understandably, researchers, clinicians, and the public are eager for a simple, accurate, and inexpensive way to predict or diagnose Alzheimer's early -- but we're not there yet."
Not by a nose.
Image by Flickr user Mark Watson (kalimstuk), used under a Creative Commons license.
I am 57 and never smelled anything in my life! Was 6 years old before I discovered that I was different. My Dad's sense of smell was not much better but mom’s was very acute. For those with loved ones who have developed what may seem like a strange desire for sweets – just remember, the taste buds on their tongue provide for sweet, sour, bitter and salt (which are the only things I have enjoyed for half a century and am doing quite fine…). So maybe their “new” likes are more about the tongue than alzheimer’s??? Dad passed 3 years ago from complications following an automobile accident and mom is now in late stages of AZ but she doesn’t seem to have lost her sense of smell. :))
@skuramoto, I'm placing this message already sent to you on the article for any others suffering the same problem. Hi skuramoto, so sorry to hear of the ruptured aneurysm and the loss of smell. However, don't give up on the smell not returning, mine went after severe sinusitis for a whole year (no smell or taste at all). My Dr suggested I imagine I could taste/smell things, obviously it's never happened to him!! Anyway, one day it came back just as though a switch had been flicked on and has been fine ever since!! I sincerely wish the same for you, but never give up! This comes along with a huge {{{hug}}} and a prayer for your well-being. Love and best wishes, Sue x
Anonymous, I'm glad you made it. Vice President Joe Biden, as you know, also had a ruptured brain aneurysm and so did my former neighbor across the street. I hope your sense of smell comes back.
I had a ruptured brain aneurysm 20 months ago and lost my sense of smell. The doctors say it may come back, but I need to give it about two years. I hope it does because I miss the smell of the roses from my garden and the smell of food. Discovered that I had lost my sense of smell when I couldn't smell tea at a tea shop. That was a sad day but things are improving.
This all makes sense. he seems to no only have lost his sense of smell but also his appetite! i have read before that that is also a sign of progressing AZ. The only thing he wants are sweets... ice cream, donuts, candy! Salad? Forget it. Meat... doesn't like his bottom plate so has trouble chewing! His blood sugar is elevated and i am afraid it is just a matter of time until he develops full blown diabetes! Life is not getting easier on this, my 76th birthday! This caregiver is hanging by a very thin thread!
My mother had alzheimers and lost her sense of smell and didn't seem to enjoy anything but sweets.
I have had MS for 20 years and 6 years ago started gradually losing my sense of smell and taste. After I year I had lost all my sense smell and most of my taste. I live in a bush fire zone but definitely never smelt when there was a fire or back burning going on. This persisted for several years. Then 3 years ago I started taking low dose naltrexone (it modulares the immune system) after a year I noticed my taste and then smell returning, I now have about 80% of my taste back but only about 60% of my smell. For me the sense of smell definitely seems to be more sensitive/vulnerable I can smell the fragrance in flowers faintly and sometimes rain. Yesterday I left an oven glove on the stove and smelt it burning (after a bit). I have trouble with word retrieval but so far by brain seems unchanged. So mariaconz seems to be spot on about smell being related to lesions.
how, interesting! i have been noticing that Cort doesn't smell things that I smell, ie wood smoke from a chimney. he always had the more acute sense smell of the two of us! Never thought about it being connected to AZ! Do you think that means that, if there were a fire in the house, he wouldn't notice!
My father-in-law has Alzheimer's and has lost his sense of smell and taste. He now adds Sweet & Low to everything he eats....soup, hamburgers, hot dogs, etc.
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Just from my own experience: my mom has Alzheimer's (so did three of her siblings; they have all died.) Mom came to live with me almost two years ago. I had a home health aide for her, but Mom stopped exercising and walking -- and watched tv all day. I knew the arrangement wasn't the best for her. But I didn't want to move her to assisted living.... until one very scary evening when I got home from work. The aide had left for the day. I walked in - and the smell of gas was so intense I gagged. Mom had somehow turned on the gas stove - but it wasn't lit. She was in a fog of propane gas -- DID NOT SMELL A THING. The worst part: she was sitting next to the pellet stove!!! Propane gas and a spark -- Mom almost blew herself up, and not once noticed the gas odor. That made up my mind about moving her to a safer place. But it also abruptly proved that AD damages parts of the brain that do not involve memory.
PoloMom, excellent point! Maybe there is a possibility that one has not lost the sense of smell, but fails to recognize the scent or the name of the scent.
There is the possibility that one has not lost the sense of smell, but fail to recognize that is what happening or the name of what they can smell. I would rely on tiny changes in actions, reactions, and other common everyday functions first. I remember being astonished when one evening, when my sister was confused by something very simple. It was the first time the Alzheimer's bell went off in my thinking process. All had semd so normal until that night. Slowly the bells kept ringing.
I recall reading a few years ago that high doses of antibiotics like penicillin can cause loss of smell/taste, and this has been my experience. At least I hope that's the explanation. Anyone know about this?
My mother had Alzheimer's and died at age 86. She lost her sense of smell a year before she died. I don't think any one test can fit all people. It seems every- one has different problems at different times during the course of Alzheimer's. Along with every one else,I pray they do come up with a true way of finding it early.
...the science in this case as written isn't convincing. So far too little is known about Alzheimer's and the brain. If scientists were talking about pregnancy and birth, that would be one thing. Physicians root around in women's organs all the time. Neurology is something else again.
My husband lost his sense of smell about 20 years ago. He now has Parkinson's with Lewy body dementia.
cyhaynes, I believe you! And I don't believe the study that said that losing the sense of smell is not a predictor of Alzheimer's. Lesions on the brain would naturally impair the senses. My mother-in-law has Alzheimer's and she's lost her taste for food.
My mom did lose sense of smell.....developed Alzheimer's.
The jury is still out.