For the elderly, poor smell may signal the beginning of the end

If your grandmother can't differentiate between smells, it may be sign the Grim Reaper is on his way to visit -- at least that's the conclusion of researchers at the University of Chicago.
In a survey of 3,000 men and women, ages 57 to 85, those with the poorest sense of smell were four times more likely to die within the following five years. For those able to properly identify smells, the chance of dying within five years was 10 percent. For those incapable of differentiating between odors, the chance of dying rose to 39 percent. Moderately capable sniffers had a 19 percent chance of dying within five years.
To measure a person's sense of smell, experimenters presented participants with a magic marker-like smelling stick, called Sniffin' Sticks, which emitted one of several smells -- including peppermint, fish, orange, rose and leather. The men and women were asked to correctly identify the stench.
Remarkably, the researchers at Chicago's School of Medicine found that only severe liver damage was a better predictor of mortality than olfactory dysfunction. A diagnosis of heart failure, cancer or lung disease were all less reliable indicators.
"We think loss of the sense of smell is like the canary in the coal mine," lead study author Dr. Jayant M. Pinto, said in a press release. Pinto is an associate professor of surgery and an expert in genetics; he specializes treatment of diseases affecting the olfactory system and sinuses.
"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," Pinto added. "Our findings could provide a useful clinical test, a quick and inexpensive way to identify patients most at risk."
"Of all human senses," Pinto said, "smell is the most undervalued and under-appreciated -- until it's gone."
The study was published this week in the journal PLOS ONE.