Your Sense of Smell Could Predict When You'll Die

[Buster's Uncle]

Your Sense of Smell Could Predict When You'll Die
LiveScience.com
By Elizabeth Palermo, Staff Writer  7 hours ago



If you want to know how long you'll live, your nose might help you sniff out the answer, a new study suggests.

In a study of older adults, researchers have found a link between the inability to identify certain scents— like peppermint or fish — and an increased risk of mortality over the next five years. Known as "olfactory dysfunction," the loss of smell is an even stronger predictor of when a person will likely die than conditions such as heart failure, cancer or lung disease, according to researchers at the University of Chicago.

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

For the study, researchers administered a simple smell test to 3,005 participants ages 57 to 85. Each participant was asked to identify five common smells: peppermint, fish, orange, rose and leather. The majority of participants (nearly 78 percent) were found to have normal smelling abilities, meaning they correctly identified at least four of the five smells. Nearly twenty percent correctly identified two or three of the five scents, and the remaining 3.5 percent of participants could identify none or only one of the five scents.

Five years after this initial smell test, the researchers confirmed which of the study participants were still alive. They found that 430 of the original smellers (12.5 percent) had passed away, including 39 percent of those who had shown significant loss of smelling power five years earlier (i.e., they had identified none or only one of the test scents). Nineteen percent of the participants who had exhibited moderate smell loss five years prior were among those who died. However, just 10 percent of those who aced their smell tests died within the five-year period, the study found.

"Obviously, people don't die just because their olfactory system is damaged," Martha McClintock, co-author of the study and a professor of psychology at the University of Chicago, said in a statement. However, a decreased ability to smell may signal what McClintock called a "decrease in the body's ability to rebuild key components that are declining with age," leading to death by other causes.

Olfactory dysfunction, as McClintock noted, could be a sign of slowed cellular regeneration. Or, it could be the result of years of toxic environmental exposures, the researchers said.

In the paper outlining their study, the researchers noted the role of olfaction (the ability to smell) as an ancestral chemical system that's linked to many physiological processes. For example, smell helps humans maintain proper nutrition, aiding appetite and preference for certain kinds of food. The ability to smell is also linked to the detection of environmental hazards and pathogens and is even associated with emotions and memory, the researchers pointed out.

Other studies on ways to predict mortality have focused more on physical indications that health might be failing. One study, conducted in 2011 by researchers at the University of Pittsburgh, found that people who walk 1 meter per second (about 2.25 mph) or faster consistently live longer than others of their age and sex who walk more slowly.

And a 2010 study based on a review of 28 smaller studies found that people who perform badly on simple physical tests — including those related to gripping, walking, rising from a chair and balancing on one leg — are at an increased risk of death compared with those who perform well on such tests.

But using smell to predict mortality might be easier than conducting tests for physical capabilities, Pinto said. The smell test conducted for the study used "Sniffin' Sticks," odor-dispensing devices that look like felt-tip pens and are loaded with aromas rather than ink.

"Our findings could provide a useful clinical test — a quick and inexpensive way to identify patients most at risk," Pinto said.

The study was published today (Oct. 1) in the journal PLOS ONE.


http://news.yahoo.com/sense-smell-could-predict-youll-die-185341887.html

[Buster's Uncle]

Loss of smell may be predictor of death in older adults: study
Reuters
By Bill Berkrot  8 hours ago



(Reuters) - Being unable to smell bacon frying may be far more dire than simply missing out on one of life's pleasures. In older adults, it could be a predictor of increased risk of death within five years.

In a study of more than 3,000 people aged 57 to 85, 39 percent of subjects who failed a simple smelling test died within five years, according to results published on Wednesday in the science journal PLOS ONE.

That compared with a 19 percent death rate within five years for those with moderate smell loss and 10 percent for those deemed to have a healthy sense of smell.

"Compared to a person with a normal sense of smell, a person with an absent sense of smell has three times greater risk of dying within a five-year span," Dr. Jayant Pinto, the study's lead author, said in a telephone interview.

"What this tells us is your sense of smell is a great indicator of your overall health," said Pinto, an associate professor at the University of Chicago who specializes in genetics and treatment of olfactory and sinus disease.

He likened the loss of smell to a canary in a coal mine. "It doesn't cause death, but it's an early warning that something has gone badly wrong."

The smell test was conducted in 2005 using "Sniffin' Sticks," which resemble felt-tip pens, that were loaded with five different odors subjects were asked to identify: peppermint, fish, orange, rose or leather.

Nearly 78 percent of those tested were able to identify at least four of the five scents and so classified as having normal sense of smell. Almost 20 percent got two or three of the scents right, while the remaining 3.5 percent could correctly identify one or none of the five, researchers said.

In 2010 and 2011, the survey team confirmed which participants were still alive. During the five years, 430 of the 3,005 subjects, or 12.5 percent, had died.

Researchers conducted interviews to adjust for variables and risk factors, such as age, smoking, alcohol use, overall health and socioeconomic status. In the end, those with greater smell loss when first tested were substantially more likely to have died five years later.

"It predicted it quite strongly," Pinto said.

Researchers noted that a healthy olfactory system has stem cells that self-regenerate. They speculated that a loss of smell could signal a decrease in the body's ability to rebuild key components and may be a harbinger of more serious health problems.

"If one's sense of smell is in decline, it's a warning sign for doctors taking care of such patients," Pinto said.

(Reporting by Julie Steenhuysen and Bill Berkrot; Editing by James Dalgleish)


http://news.yahoo.com/loss-smell-may-predictor-death-older-adults-study-183011322.html