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Have trouble smelling things? It could mean you’re dying

Have trouble smelling things? It could mean you’re dying

Researchers have given a new meaning to the age-old saying that the nose knows, with a new study that suggests the loss of smell may be a harbinger of death.

Scientists at the University of Chicago have discovered that that the decline in the ability to sense common odours in our elderly years doubles the probability of death within five year time.

They conducted a survey of just over 3,000 participants aged between 57 and 85, having them identify common smells like orange, peppermint, fish and leather. Five years later, nearly 15% had died, with nearly 60% coming from groups that had been identified as being either smell-deficient or completely unable to smell. The finding even held true when accounting for variables like age, sex, race, and socio-economic status, and even when accounting for disease, smoking and alcohol use.

Authors of the study published in the journal PLOS ONE, are quick to point out, however, that the inability to smell does not directly lead to death. Instead, they believe it is a natural signal that something physiologically has gone awry. The olfactory system relies on stem cell regeneration and renewal to function normally, and the decline in sensing odours may very well be a marker – the body’s own alarm system going off – warning us that this natural process has begun to slow down and turn off.

“We think loss of the sense of smell is like the canary in the coal mine,” said lead author Jayant M. Pinto, an associate professor of surgery at the University of Chicago, in a press statement.

The good news is that Pinto and his team believe their new findings can be used to our benefit.

”It doesn’t directly cause death, but it’s a harbinger, an early warning system, that something has already gone badly wrong, that damage has been done,” he said. “Our findings could provide a useful clinical test, a quick and inexpensive way to identify patients most at risk.”

Animals can easily beat humans when it comes to their olfactory abilities. While it’s estimated that humans have about 6 million smell-sensing cells, dogs have about 220 million. In terms of mammals and their olfactory receptor genes – genetic markers that are dedicated to smelling – the African elephant is king, with about 10 times more genes than humans.

Meanwhile, sharks have their smell tuned-in specifically for hunting down prey, so they have the ability to sense blood in as little concentrations as one part per billion in water.

Humans’ sense of smell has been short-changed with the common notion that we can only distinguish 10,000 distinct odours. This has been proven wrong in a study in the journal Science, that showed that humans actually have a much more powerful sense of smell than anyone ever thought, with the capability to detect over 1 trillion odours. And our sniffing skills have also been tied to some nifty abilities, including telling how much fat is in our food.

I guess I’m going to make sure from now on to stop and smell those roses – it may keep tabs on my health.