Decreased ability to identify odours can predict death
The ability to distinguish between odours declines steadily with age, and age-related smell loss can have a substantial impact on lifestyle and wellbeing for the elderly.
“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 odours that signal danger, like a gas leak or smoke. They may not notice lapses in personal hygiene,” said 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.
“Of all human senses,” he said, “smell is the most undervalued and underappreciated—until it’s gone.”
And for older adults, being unable to identify scents is also a strong predictor of death within five years, according to a study. 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 Pinto, the study’s lead author. “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. University of Chicago Medicine and Biological Sciences
