[Editor's note: we received two separate reports on this story and wanted to give attribution to both submitters. They are presented here in the order received.]
Failing a smelling test is a strong predictor of death within 5 years, according to a new study (full text).
Thirty-nine percent of study subjects who failed a simple smelling test died during that period, compared to 19 percent of those with moderate smell loss and just 10 percent of those with a healthy sense of smell.
The hazards of smell loss were "strikingly robust," the researchers note, above and beyond most chronic diseases. Olfactory dysfunction was better at predicting mortality than a diagnosis of heart failure, cancer or lung disease. Only severe liver damage was a more powerful predictor of death. For those already at high risk, lacking a sense of smell more than doubled the probability of death.
"We think loss of the sense of smell is like the canary in the coal mine," said the study's lead author Jayant M. Pinto, MD, an associate professor of surgery at the University of Chicago who specializes in the genetics and treatment of olfactory and sinus disease. "It doesn't directly cause death, but it's a harbinger, an early warning that something has gone badly wrong, that damage has been done. Our findings could provide a useful clinical test, a quick and inexpensive way to identify patients most at risk."
Hugh Pickens writes:
Mo Costandi writes at The Guardian that a new study shows that losing one’s sense of smell strongly predicts death within five years, suggesting that the nose knows when death is imminent, and 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.” Jayant Pinto of the University of Chicago prepared special felt-tipped pens scented with five common odors—fish, leather, orange, peppermint and rose—and presented them one by one to volunteers. After each presentation, the volunteer was shown pictures and names of four possible answers, and was asked to select the correct one. Getting one answer wrong was considered okay, or “normosmic”, but two or three errors labelled a person as “hyposmic”, or smell-deficient, and four or five counted them as “anosmic”, or unable to smell. Five years later, the researchers tracked down as many of the same participants as they could, and asked them to perform this smell test a second time. 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 researchers stress that it is unlikely to be a cause of death itself, arguing only that it is a harbinger for what is to come. 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 odours. Loss of smell may indicate that the body is entering a state of disrepair, and is no longer capable of repairing itself.
lhsi's summary was succint and concise but left out an important part. It makes it seem like the researchers don't even have any hypothesis linking the loss of smell to approaching mortality.
Hugh's summary contains bit too much details for summary, but also did describe the important part:
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 odours. Loss of smell may indicate that the body is entering a state of disrepair, and is no longer capable of repairing itself.
The story grabbed my attention because I have an elderly parent.
Thank-you for your feedback!
Ordinarily, I would merge the two submissions together. In this case, lhsi's submission had already been approved by another editor and was in the story queue. As I was looking through the submission queue, I saw Hugh's submission. It was then that I remembered I'd previously seen his
journal entry [soylentnews.org] on this story.
Given the very different perspectives and writing styles offered by both submitters, any attempt to merge the two would result in a dramatic change to their submissions... akin to putting words in their mouths. I found that choice unacceptable. Still, I wanted to give credit to both of them for their efforts and could only think of this approach to do so.
I am open to suggestions as to how else this could have been handled.
And, to keep this somewhat on-topic... though my sense of smell ordinarily takes a back-seat to visual, auditory, and tactile inputs, there have been times when a sense of smell was most important. Like noticing something in the fridge had gone bad and throwing it out instead of eating it and getting sick. Then there was the time when I had a really bad cold and everything smelled (and tasted) bland. I mostly lost my appetite, even though I knew I should eat to keep up my strength to fight what was ailing me.
There's something about the aroma of a cup of coffee, or freshly-baked bread or cookies, or of a burger on the grill that really whets my appetite!
About 20 years ago, I was diagnosed with and treated for cancer. I don't know if it was the cancer itself or the chemotherapy I received to fight it, but my senses of taste and smell were permanently altered. I was 17 years old at the time, and foods I normally enjoyed like strawberries, shrimp, mayonnaise, or coleslaw, I found I was repulsed by after the treatments were over and I was in remission. Just the smell of seafood, cabbage, or mayonnaise to this day makes me gag, even though I loved them before getting cancer.
I've also found that I enjoy foods that I didn't like before. I used to hate the smell and taste of coffee, for example, but one day a few years after my last treatment I realized I like the smell of it. I tried a cup, and absolutely loved it; now I can't get enough.
My doctor had warned me that many of his patients experienced dramatic changes in their bodies as a result of surviving cancer, and it looks like he was right in my case.
I have a mental illness called bipolar-type schizoaffective disorder. It's much like being manic-depressive and schizophrenic at the same time.
The last six or eight weeks I have been depressed. I did not catch on at first; it happened gradually I didn't really noticed but then I did start to notice that lots of things just aren't right. Much of what I commonly do, that I find interesting or enjoyable, I just cannot be bothered to deal with.
More recently it occurred to me that having lost interest in cooking is making my depression worse, because I don't look forward to my meals. I have been literally living on oatmeal and peanut butter and jelly sandwiches because it strikes me as too much effort to purchase the groceries required to cook any interesting meals, despite that I love to cook and that I love to it.
I know very well that if I persist on this course, the chances are quite good that before long I will become an ex-parrot at my own hand, so for the last little while I've been making a conscious, concerted effort to lift myself by my bootstraps, to do things I know I usually enjoy, even if they don't seem to me that I would enjoy them.
Like yesterday morning I went out to a deli and had a really tasty, nutritious breakfast.
Now suppose you lost your sense of smell. How much would you enjoy food? Cooking? Wildflowers? Walking in the woods or on the beach? The familiar smells of your home and your loved ones?
It would be quite unusual not to lose all of your will to live and so just give up.
It also can't help your lifespan if you eat bad or inferior food/drink more often than average because you can no longer smell that it's bad...
Have you considered other hobbies like recreational sports, art, music, literature?
"Without music, life would have been a mistake."
Editors done well here. You lot makes the difference - don't turn into cynical trolls like those at slashdot are half the time.
I thought you handled it well, far better than at the green site.