From: drarwingnuttephd@gmail.com   
      
   Decreased Ability to Identify Odors Can Predict Death    
   Olfactory dysfunction is a harbinger of mortality    
      
   Released: 25-Sep-2014 10:00 AM EDT    
   Embargo expired: 1-Oct-2014 2:00 PM EDT            
   Source Newsroom: University of Chicago Medical Center    
   more news from this source    
   Contact Information    
   Available for logged-in reporters only    
   Citations    
   PLOS One, October 1, 2014    
   Newswise -- For older adults, being unable to identify scents is a strong   
   predictor of death within five years, according to a study published October   
   1, 2014, in the journal PLOS ONE. Thirty-nine percent of study subjects who   
   failed a simple smelling    
   test died during that period, compared to 19 percent of those with moderate   
   smell loss and just 10 percent of those with a healthy sense of smell.    
   The hazards of smell loss were "strikingly robust," the researchers note,   
   above and beyond most chronic diseases. Olfactory dysfunction was better at   
   predicting mortality than a diagnosis of heart failure, cancer or lung   
   disease. Only severe liver damage    
   was a more powerful predictor of death. For those already at high risk,   
   lacking a sense of smell more than doubled the probability of death.    
   "We think loss of the sense of smell is like the canary in the coal mine,"   
   said the study's lead author Jayant M. Pinto, MD, an associate professor of   
   surgery at the University of Chicago who specializes in the genetics and   
   treatment of olfactory and    
   sinus disease. "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.   
   Our findings could provide a useful clinical test, a quick and inexpensive way   
   to identify patients    
   most at risk."    
   The study was part of the National Social Life, Health and Aging Project   
   (NSHAP), the first in-home study of social relationships and health in a   
   large, nationally representative sample of men and women ages 57 to 85.    
   In the first wave of NSHAP, conducted in 2005-06, professional survey teams   
   from the National Opinion Research Center at the University of Chicago used a   
   well-validated test--adapted by Martha K. McClintock, PhD, the study's senior   
   author--for this field    
   survey of 3,005 participants. It measured their ability to identify five   
   distinct common odors.    
   The modified smell tests used "Sniffin'Sticks," odor-dispensing devices that   
   resemble a felt-tip pen but are loaded with aromas rather than ink. Subjects   
   were asked to identify each smell, one at a time, from a set of four choices.   
   The five odors, in    
   order of increasing difficulty, were peppermint, fish, orange, rose and   
   leather.    
   Measuring smell with this test, they learned that:    
   *        Almost 78 percent of those tested were classified as "normosmic,"   
   having normal smelling; 45.5 percent correctly identified five out of five   
   odors and 29 percent identified four out of five.    
   *        Almost 20 percent were considered "hyposmic." They got two or three   
   out of five correct.    
   *        The remaining 3.5 percent were labelled "anosmic." They could   
   identify just one of the five scents (2.4%), or none (1.1%).    
   The interviewers also assessed participants' age, physical and mental health,   
   social and financial resources, education, and alcohol or substance abuse   
   through structured interviews, testing and questionnaires. As expected,   
   performance on the scent test    
   declined steadily with age; 64 percent of 57-year-olds correctly identified   
   all five smells. That fell to 25 percent of 85-year-olds.    
   In the second wave, during 2010-11, the survey team carefully confirmed which   
   participants were still alive. During that five-year gap, 430 (12.5%) of the   
   original 3005 study subjects had died; 2,565 were still alive.    
   When the researchers adjusted for demographic variables such as age, gender,   
   socioeconomic status (as measured by education or assets), overall health, and   
   race, those with greater smell loss when first tested were substantially more   
   likely to have died    
   five years later. Even mild smell loss was associated with greater risk.    
   "This evolutionarily ancient special sense may signal a key mechanism that   
   affects human longevity," noted McClintock, the David Lee Shillinglaw   
   Distinguished Service Professor of Psychology, who has studied olfactory and   
   pheromonal communication    
   throughout her career.    
   Age-related smell loss can have a substantial impact on lifestyle and   
   wellbeing, according to Pinto, a member of the university's otol   
   ryngology-head and neck surgery team. "Smells impact how foods taste. Many   
   people with smell deficits lose the joy of    
   eating. They make poor food choices, get less nutrition. They can't tell when   
   foods have spoiled or detect odors that signal danger, like a gas leak or   
   smoke. They may not notice lapses in personal hygiene."    
   "Of all human senses," Pinto said, "smell is the most undervalued and   
   underappreciated--until it's gone."    
   Precisely how smell loss contributes to mortality is unclear. "Obviously,   
   people don't die just because their olfactory system is damaged," McClintock   
   said.    
   The research team, which includes biopsychologists, physicians, sociologists   
   and statisticians, is considering several hypotheses. The olfactory nerve, the   
   only cranial nerve directly exposed to the environment, may serve as a   
   conduit, they suggest,    
   exposing the central nervous system to pollution, airborne toxins, pathogens   
   or particulate matter.    
   McClintock noted that the olfactory system also has stem cells which   
   self-regenerate, so "a decrease in the ability to smell may signal a decrease   
   in the body's ability to rebuild key components that are declining with age   
   and lead to all-cause mortality.   
   "    
      
   The study, "Olfactory Dysfunction Predicts 5-year Mortality in Older Adults,"   
   was funded by the National Institutes of Health--including the National   
   Institute on Aging, the Office of Women's Health Research, the Office of AIDS   
   Research, the Office of    
   Behavioral and Social Sciences Research--and the McHugh Otolaryngology   
   Research Fund, the American Geriatrics Society, and the Institute of   
   Translational Medicine at the University of Chicago.    
      
   [continued in next message]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)