The Hidden Signal: How Does Your Nose Detect the Scent of Impending Death

If you’re eager to learn how long you’re going to live, a sniff may help you find out, according to a new study.

The study was done with elderly adults and what the researchers discovered was a connection between the inability to identify some scents, like fish or peppermint, and a higher risk of mortality in the next five years. 

Known as olfactory dysfunction, the loss of smell is an even stronger predictor of a person’s chance of death than conditions like cancer, lung disease, and heart failure.

The lead author of the study, Dr. Jayant Pinto, an associate professor of surgery at the University of Chicago, explains that they think that sense of smell is like the canary in the coal mine. 

It can’t cause death directly, but it may be an early sign that something has gone wrong and that damage has happened.

The Link Between Smell & Incoming Death

For the purposes of the study, researchers did a test with 3,005 participants aged 57 to 85. Each participant was asked to identify five common smells: fish, peppermint, orange, leather, and rose. 

Most of the participants, around 78 percent of them, were found to have a normal smelling ability and were able to correctly identify at least four of the five smells. 

Almost twenty percent correctly identified two or three of the five scents whereas the rest 4.6 percent of participants were able to identify none or only one of the five scents.

Five years after this test, the researchers confirmed which of the participants in the study were still alive. 430 of them or 12.5 percent had passed away, including 39 percent of those who had loss of smelling power five years earlier. 

19 percent of the participants who had a moderate loss of smell five years prior were among the ones who died. But, only 10 percent of those who aced the tests died in these five years. 

According to Martha McClintock, co-author of the study and a professor of psychology at the University of Chicago, people don’t die only because their olfactory system is damaged. 

A lowered sense of smell may signal what McClintock refers to as a decrease in the body’s capacity to rebuild key elements which decline with age and lead to death by other causes.

Olfactory Dysfunction: A Sign of Slowed Cellular Regeneration

According to McClintock, olfactory dysfunction may be a sign of slowed cellular regeneration or a consequence of years of toxic environmental exposure. 

According to the researchers, the ability to smell is associated with numerous physiological processes. For example, it helps humans maintain a balanced nutrition by aiding appetite and preference for specific foods. 

It’s also associated with the detection of hazards and pathogens and even with emotions and memory. Other studies for morality prediction were focused on physical indications that one has failing health. 

In one 2011 study done by a team of researchers at the University of Pittsburgh, it was found that the people who walked a meter per second or faster consistently lived longer than others of the same age and sex but who walked slower. 

Another 2010 study based on a review of 28 smaller studies concluded that people who didn’t perform well on physical tests associated with walking, gripping, balancing on one leg, and rising from a chair had a higher risk of death in comparison to the others who performed well on these tests.