A new study has revealed that decreased ability to identify odours can predict death within five years. According to the study, 39% of respondents, who failed a simple smelling test, died during that period, compared to 19% of those with moderate smell loss and just 10% 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.
Study's lead author Jayant M Pinto, MD, an associate professor of surgery at the University of Chicago, said that they think loss of the sense of smell is like the canary in the coal mine. 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. Their findings could provide a useful clinical test, a quick and inexpensive way to identify patients most at risk.