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Lost Sense of Smell Is a Strong Predictor of Death Within 5 Years
HughPickens.com writes: Mo Costandi reports at The Guardian that a new study shows losing one's sense of smell strongly predicts death within five years, suggesting that smell may serve as a bellwether for the overall state of the body, or as a marker for exposure to environmental toxins. "Olfactory dysfunction was an independent risk factor for death, stronger than several common causes of death, such as heart failure, lung disease and cancer," the researchers concluded, "indicating that this evolutionarily ancient special sense may signal a key mechanism that affects human longevity." In the study, researchers tested a group of volunteers for their ability to correctly identify various scents. Five years later, they retested as many of the volunteers as they could find.
During the five-year gap between the two tests, 430 of the original participants (or 12.5% of the total number) had died. Of these, 39% who had failed the first smell test died before the second test, compared to 19% of those who had moderate smell loss on the first test, and just 10% of those with a healthy sense of smell. Despite taking issues such as age, nutrition, smoking habits, poverty and overall health into account, researchers found those with the poorest sense of smell were still at greatest risk. The tip of the olfactory nerve, which contains the smell receptors, is the only part of the human nervous system that is continuously regenerated by stem cells. The production of new smell cells declines with age, and this is associated with a gradual reduction in our ability to detect and discriminate odors. Loss of smell may indicate that the body is entering a state of disrepair, and is no longer capable of repairing itself.
During the five-year gap between the two tests, 430 of the original participants (or 12.5% of the total number) had died. Of these, 39% who had failed the first smell test died before the second test, compared to 19% of those who had moderate smell loss on the first test, and just 10% of those with a healthy sense of smell. Despite taking issues such as age, nutrition, smoking habits, poverty and overall health into account, researchers found those with the poorest sense of smell were still at greatest risk. The tip of the olfactory nerve, which contains the smell receptors, is the only part of the human nervous system that is continuously regenerated by stem cells. The production of new smell cells declines with age, and this is associated with a gradual reduction in our ability to detect and discriminate odors. Loss of smell may indicate that the body is entering a state of disrepair, and is no longer capable of repairing itself.
1. Harvest nose stem cells from homeless people
2. ???
3. Profit!
Something smells funny about this story.
is what so often keeps you out of trouble such as knowing when food has gone bad or you need to wash. From working in a nursing home, I think it is the lack of smell that kills a lot of people. I'm sure the lack of stem cell regeneration hurts, but not knowing when to was your hands or not knowing if food is bad can be a killer for someone with a weak immune system.
Man this thing is drawing some invalid conclusions. Gotta love these digested tertiary sources.
"Olfactory dysfunction was an independent risk factor for death, stronger than several common causes of death, such as heart failure, lung disease and cancer," the researchers concluded, "indicating that this evolutionarily ancient special sense may signal a key mechanism that affects human longevity."
I doubt the "loss" of smell is the cause of much at all but rather can be a symptom of a problem. Sounds like just another Corn-Flake theory...Most people who were involved in accidents or became sick had some sort of breakfast that morning.
DAMN YOU EVIL BREAKFAST!!!
Lolz
So that's why if they can't smell their own urine, they usually die within a few years. Good to know it's not just "because they got used to the smell." And no, I'm not being facetious here.
"Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
The nose knows...
It's the slashdot beta, it sucks so bad that there are a few hundred flies around it.
OK, Ok, I agree, correlation is not causation. I am not claiming to be an expert or have all the answers. All I am doing is raising the question: Why do they always occur together? Is it a mere coincidence? I report, fair and balanced, and you decide. That is all I am saying.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
"...may indicate that the body is entering a state of disrepair, and is no longer capable of repairing itself."
Yeah. There's a name for that. It's called "getting old".
Can you smell it? Good, you're healthy.
We already know dead people don't smell well.
My father was a masonry construction worker. He lost his sense of smell 50 years before he died from throat cancer (doctors gave him six months, but he died six weeks later). The study was off by a factor of 10.
Not really happy to read this. Part of my cancer treatment was radiation therapy to the head. I had a severe loss of taste, but smell was nearly intact. With an overly sensitive nose, I guess I was down to what would be a "normal" level. Considering what could have happened (a partial list): loss of sight, loss of hearing, loss of hair, damage to vision, damage to tears, difficulty in swallowing, loss of muscle control of tongue, loss of teeth, loss of smell, inability to chew, and more. Losing taste for a few months was not bad. I ate a lot of Indian food. The problem was eating enough to maintain weight to have the treatment mask fit. Allowable weight variation was zero lbs. I just used a portion control. I am athletic and continued bike miles during treatment. I would do the "french fry" trick in reverse. In a typical diet, you set aside the four fries you are "allowed" to eat, creating a DO NOT EAT pile. I created a somewhat larger pile of YOU MUST EAT THIS. As a conditioned (albeit older athlete) I knew how much to eat to balance calories out with calories in. I was used to being so tired that taste really was never an issue. Tasting takes effort. BTW, taste did come back but still not at 100%. Considering the option -- death -- loss of taste temporarily was OK.
In GOP USA time to go to lockup to be your doctor as that will black list you and lockup will be the only place to see a doctor.
There's too much coke and too much smoke
Look what's going on inside you
Ooooh that smell
Can't you smell that smell
Ooooh that smell
The smell of death surrounds you
"Flyin' in just a sweet place,
Never been known to fail..."
Smell is the shittiest sense we have - there are no "good" smells except those that seem to overpower the most shitty smells and/or the utter lack of smell. Smell exists almost exclusively to tell us what to avoid - you might as well be saying "people who just had their eyes gouged out after seeing without issue for their entire lives and going unassisted in a city are likely to be hit by a car within 5 years" - given the number of things in our modern lives that can kill us immediately or via long-term exposure it's no real shocker that without a sense of smell people will off themselves on accident.
Wow, I lost most of my sense of smell over 10 years ago after what my doctors suspect was a virus. I still feel pretty good. I'm in good health with low cholesterol and normal blood pressure. Overall, I feel pretty good for a dea
if nobody will go into the room to check on the patient because the door is melting, that's also a solid indication that first one in can turn off the IV drip.
if this is supposed to be a new economy, how come they still want my old fashioned money?
Nobody tell CmdrTaco about this.
This sounds like a Telomere Canary. That is, an outward sign that cells are no longer able to replicate accurately.
Well, my sense of smell is intact. I excercised it thoroughly but accidentally by going to a hobby store two Saturdays ago. and passing the gaming tables.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
That you know their time is up.
First off, the original article is open access at PLOS ONE here: http://www.plosone.org/article...
The summary statement, "The tip of the olfactory nerve, which contains the smell receptors, is the only part of the human nervous system that is continuously regenerated by stem cells", implies several things that are misleading and/or totally untrue.
The tip of the olfactory nerve is the olfactory epithelium, where the olfactory sensory receptor cells are located. The olfactory nerve travels through the cribriform plate, a porous area of skull, where it then synapses with the olfactory bulb. The olfactory bulb has several cell types, and only one of these, inhibitory granule cells, is continually regenerated via neuroblasts migrating along the rostral migratory stream from the sides of the lateral ventricles. These cells are thought to play a role in associative learning and coding of new olfactory cues. The olfactory nerve does not have a capacity for self-renewal, nor do any of the olfactory receptor cells.
Furthermore, there is more than one area where neurons undergo continual self-renewal. The dentate gyrus of the hippocampus also fosters a neurogenic niche, and these new cells have important implications for learning, memory, stress, and emotion that we are just beginning to understand.
Thirdly, we don't really know if neurogenesis in the olfactory bulb has anything at all to do with the observed results because this was not measured in the study, but it is a plausible hypothesis for future study.
As a side note, one of the very intriguing aspects of neurogenesis is that after cortical injuries such as trauma or stroke, neuroblasts from the ventricles migrate toward the lesion, rather than toward the olfactory bulb. These cells are capable of forming electrochemically active synapses at the lesion site and appear to aid in recovery. Unfortunately, astrocytic scarring and inflammation limit the regenerative capacity of these cells - but this is an area of intense research in the field of neurotrauma. My current (undergraduate) research is focused on analyzing the effects of post-injury recovery environment (for rats) on subventricular and hippocampal neurogenesis.
For a good summary on neurogenesis:
http://chuang01.web.wesleyan.e...
Our sense of smell is the sense running at the lowest level. It's wired straight into the brain in the shortest path of any sense.
This is why the peanut butter smell test can help diagnose Alzheimer's disease. I would expect nontraumatic loss of smell to highly positively correlate with damage to the structures of the temporal lobe (amygdala, basal ganglia, etc). This is where memory lives (in all its forms).
Smell is a pretty raw sense, as opposed to say, vision, which is highly processed by many different cortical systems and areas. I would therefore expect it to yield the best raw cerebral status metadata.
I either NEVER had a sense of smell, or at least not since I was 5 years old. So I should have died over 25 years ago.
It is a minor inconvenience... I have to be careful about gas leaks and such.
As for food, I have a good enough sense of taste to distinguish most foods so it's not like I feel like I'm eating sawdust like some people assume.
A for the rest, just minor stuff:
Visually check to make sure I didn't step in dog poo
Don't use any fragrance or cologne... I'll never get it right
Make sure I'm always clean, and have deoderant on
etc
I always joked that I had no sense of smell. It was there, but something had to really stink to get up my nose. Considering that I also couldn't breathe through one of my nostrils, this made sense to me. Finally, after much testing and worried about sleep apnea, we found the cause of my blocked airways. A structure in my nose was trying to grow a third airway. Doing this pushed my septum over and made my one nostril's airway extremely narrow. I had surgery a few months ago to remove this structure and to fix my deviated septum. My breathing is amazingly better. (Being able to breathe through both nostrils still feels weird.) I'm waiting to see if it improves my sense of smell as my nose adjusts to its new normal.
My sci-fi novel, Ghost Thief, is now available from Amazon.com.
Slowly, camera zooms in on his nose. "Oh God. I can't smell anything. I CAN'T SMELL ANYTHING!!!"
..."Perfect Sense" http://www.imdb.com/title/tt14... Great movie.
I would think that mysteriously loosing one of your senses would be a good indicator that there is something wrong with you.
Most of us can't smell anything with a cold... so we'll all die from a 5-year cold.
I worked for several years with what was essentially concentrated vinegar. (Household is typically a 5% solution. The stuff we used was around 85%). While the area was well ventilated, my sense of smell hasn't recovered over 10 years later. I retained some sense of smell, but it has to be very bad for me to notice. My wife complains that I'm not bothered by the baby's stinky boom-booms. I call it a superpower.
scents.
My dog has no nose.
How does he smell?
Terrible.
Four years ago, I lost my sense of smell. No other physical manifestations. After a month without any smell (quite disconcerting - couldn't smell coffee, food, or anything, Took much of the color out of life), Kaiser hospital did a cat scan of my head and reported a very minor nasal obstruction, probably mucus.
Over the next few months, a weird constellation of symptoms showed up: severe anxiety. Sudden, severe depression. Occasional double vision. Absolute insomnia for four days. Bizarre - in my life, I'd never felt anything like this. (I don't do drugs, alcohol, or have any history of mental troubles)
Then my pee turned black. My wife took me to the hospital...
After sonograms & catscans, the radiologist found a walnut sized tumor on my pancreas.
The doctor looks at me and asks if I have any kids. "Sure, two of 'em," I replied.
"Then you'd better get to an attorney and make your will. Don't waste any time."
Less than 5% of pancreatic cancer patients live for 5 years. After making my will, I had a Whipple operation (don't ask), the surgeon removed the tumor (along with a gall bladder, and god knows what else). I'm still alive today, almost 4 years later, writing Python code and shell scripts. Within my field, I'm moderately well known, so I'm posting this anonymously.
Here's the important part: Pancreatic and other cancers often show strange pro-dromal symtoms, months before the obvious manifestations occur. Things like sudden onset, severe anxiety. depression, and emotional distress. And the sudden loss of smell. Sure, laugh at the postings here. But take it seriously if this happens to you or someone you know.
Loss of smell might just be from a common cold. But it may be a prodromal indicator of something serious.
Olfactory genes have a higher rate of mutation than most other genes because the DNA they are in gets packed more tightly and gets replicated later than other genes. As a result, they often show up as false positive in cancer gene searches. Read more here:
http://www.nature.com/nature/journal/v499/n7457/full/nature12213.html
This might mean that they're a canary-in-the-coal-mine: If someone's DNA replication is starting to suffer in general, olfactory genes might be where the breakdown shows up first and most dramatically.
Contrary to all the speculative guesses in the comments, the researchers do have a hypothesis for this.
From the linked PLOS article:
2bits.com, Inc: Drupal, WordPress, and LAMP performance tuning.
What's this stuff in the back of the fridge? It doesn't smell bad. I think I'll reheat it for lunch.
Have gnu, will travel.
mod parent up. This guy has actually paid his dues.
... the reason I poot a so much because I'm just checking on her health and stuff.
It little behooves the best of us to comment on the rest of us.
What did they die from?
Doctor, I have lost my sense of smell. Can you give me an anti-death pill please? Thanks.
Doctor, I just died. Can you revive me please?
Doctor, I want to live forever. Please give me more anti-death pills please?
While they did control for "cognitive deficits" to some extent, what they did not control for is the likelihood that some subjects had pre-clinical Alzheimer's or Parkinson's disease (among other things), both of which are associated with very early olfactory deficits (prior to cognitive deficits). In fact, the aggregates that cause Parkinson's disease appear in the olfactory bulb before any other brain area. So it would be interesting to know about the neuropathology of the individuals who died during the 5-year period.
Of course, if this is just used as a diagnostic, then it doesn't matter. Having a bad sense of smell might be a good reason to get tested for other conditions, or to get early intervention for AD or PD. But it probably isn't as causal as the numbers in the paper would suggest.
I lost my sense of smell over 15 years ago.
+1 to smoking, and for making this report complete bullcrap!
This is a story that has accumulated rounding and restatement errors in the process of being reported and summarized.
Fortunately, several Slashdot commnters with better acquaintance with the last decade of detailed stem cell research have clarified that the presence and operation of stem cells in the organs of small is more complicated and limited than the article summary suggests.
Several comments from persons who have experienced changes in their sense of smell make the point that changes in the sense of smell can be extremely important indicators changing conditions within the body.
My sense of smell changed 30 years ago when I quit smoking cigarettes and I am now in my late 60s. But what I would say personally is the interesting thing about the sense of smell is it is a subtle and very primary sense. The phrase "smells funny" is a turn of phrase or piece of speech that is based on a genuinely deep seated, direct and powerful sense.
Regarding "... more likely to die in 5 years..." this is a chance finding from a too small sample size. Much more important is the broader message: pay attention to your senses, take care of them, maintain a rich consciousness of how you and your body traverse this life.
This is useless without more information/data.
Old people are more likely to lose their sense of smell.
Old people are more likely to die within 5 years.
Therefore, people who lose their sense of smell are more likely to die within 5 years.
This is the whole "ice cream causes drownings" all over again.