“The sense of smell seems to be a good indicator of aging brain health,” said Olofsson, an associate professor of psychology at Stockholm University. “We see smell function as the ‘canary in the coal mine,'” he added.
While a direct link between smell and an increased likelihood of death has not yet been found, dementia as a cause can be ruled out, even though it has been linked previously to a diminished sense of smell. It does not explain any part of the link between smell loss and mortality risk.
“So there has to be a different, yet unknown, biological explanation for the link,” says Olofsson.
Anosmia (an impaired sense of smell) affects nearly 7 out of 10 older people, compared to 15 percent or less of younger individuals, said researchers. Older research has suggested that seniors who performed poorly on smell tests were likely to die sooner than their better scent detecting peers, with researchers left wondering if this connection might apply to middle-aged people as well and if dementia plays any role.
The Swedish study tracked nearly 1,800 adults aged 40 to 90 years old for 10 years, looking at various results that tested the sense of smell and health conditions, including mental decline. During those 10 years, 400 of the participants died.
The results of the study did show a correlation between lower scores on identification tests of smells and a higher risk of death. But the researchers couldn’t actually prove that an inability to detect common odors predicted an early death. “This effect persisted after we adjusted for education level, health status and mental functioning, variables that might otherwise determine how well we age,” Olofsson said.
There are many reasons why a person may lose their sense of smell, such as an injury or infection. There is no need to panic if you or someone you know is losing or has lost their sense of smell, as it could be due to any number of logical reasons. Perhaps speaking to your doctor will shed some light on your own particular situation.
“If their doctor thinks it’s indicated, smell testing can be performed,” said Pinto, who specializes in sinus and nasal problems. “But many people think their sense of smell is worse than it actually is when tested. Flavor is mediated by smell, so if food tastes good, then things are probably OK.”
More information on this study can be found in the March 22, 2017 edition of the Journal of the American Geriatrics Society.