A survey of 3,000 adults found 39% with the poorest sense of smell were dead within five years - compared to just 10% who identified odors correctly.
Scientists say the loss of smell sense does not cause death directly, but may be an early warning sign.
Researchers from the University of Chicago asked a representative sample of adults between the ages of 57-85 to take part in a quick smell test, reports BBC.
The assessment involved identifying distinct odors encased on the tips of felt-tip pens.
The smells included peppermint, fish, orange, rose and leather.
Five years later some 39% of adults who had the lowest scores (4-5 errors) had passed away, compared with 19% with moderate smell loss and just 10% with a healthy sense of smell (0-1 errors).
Greatest Risk
And 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.
Lead scientist, Prof Jayant Pinto, said: “We think loss of the sense of smell is like the canary in the coal mine. It doesn’t directly cause death, but it is a harbinger, an early warning system that shows damage may have been done.”
The findings could provide a useful clinical test, a quick inexpensive way to identify patients most at risk, he said.
Exactly how smell loss contributes to lifespan remains unclear, but the researchers put forward a number of possible reasons behind the link.
