Failing sense of smell may be the
canary in the coal mine as they put it in predicting death among the elderly according to a new study. The study was published in the journal PLOS ONE, showing that 395 of participants in the study lost their smell and died within 5 years. 19% of those described with
moderate smell loss and 10% of those who had a healthy sense of smell died within the same period of time.
The study came from the University of Chicago, and it was part of the National Social Life, Health, and Aging Project (NSHAP). It was, as Agence France-Presse puts it,
the first in-home study of social relationships and health in a large, nationally representative sample of men and women ages 57 to 85. Agence France-Presse describes it saying,
The hazard of smell loss were ‘strikingly robust’, according to researchers, who said that olfactory dysfunction was better at predicting mortality than a diagnosis of heart failure, cancer or lung disease.
The only thing that was a more powerful predictor of impending death was severe liver damage.
It’s still not 100% clear what the connection between your sense of smell and death is. Martha McClintock, a senior author in the study says,
Obviously, people don’t just die because their olfactory system is damaged. Some researchers, for obvious reasons, believe that it could be an indication or symptom of other problems.
Jayant Pinto, associate professor of surgery at the University of Chicago and lead author of the study says,
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 NSHAP study was conducted in 2 stages. In the first stage, 3,005 participants were involved between 2005 and 2006, and they measured how well participants were able to identify 5 well-known scents. In the second section, 5 years later, they identified who out of the 3,005 were still alive. 12.5% were dead, and there were 2,565 left living.