Not Smelling Death

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Okay, here's a cheery task. Make a list of conditions that could predict a person's death in five years. Ugh. How grim, but ok' cancer, stroke, congestive heart failure, emphysema, and kidney failure? Now you can add ' anosmia! Really? The loss of smell? I know, right?

A new study found losing our sense of smell is a predictor of death in older people. They asked about three thousand people ages 57 to 85 to identify five common scents. Five years later, the same people were called and assessed. Some of the older seniors had died and surprisingly, forty percent of them had failed the scent test five years earlier. So, their mortality rate was three times higher than those with healthy noses even after other factors were ruled out such as nutrition, mental health, smoking and alcohol.

So, why is the olfactory, or sense of smell, a predictor of impending death? This ancient ability is tied to good health and nutrition, warns us of environmental hazards, and is intimately tied to memory and emotions.

Normal olfactory function is unique in that it relies on cellular regeneration of the olfactory neuroepithelium and the hippocampus. Thus, olfactory dysfunction can result in the inhibition of stem cell turnover in olfactory tissue.

Could this indicate a problem with cellular regeneration reflecting a larger problem? The study doesn't answer this and many other questions. It certainly does not mean anosmia causes death but rather it could be a sign of health problems that directly affect longevity.

If you're concerned, there's a simple scent test available. People can use the results to search for interventions that may prolong their lives.

More Information

Olfactory Dysfunction Predicts 5-Year Mortality in Older Adults
Original research article describing the study and its results.
Pinto, J.M., K. E. Wroblweski, D.W. Kern et al PLOS One Vol 9, October 2014, e107541

Is loss of smell a 'harbinger of death'?
It's more like the canary in the coal mine.

Losing sense of smell may predict earlier death, research shows