Testing people’s sniffing power should become a regular part of a visit to the doctor, researchers have said.
They have found that older people with a poor sense of smell are up to 50 per cent more likely to die in the next 10 years.
Their findings, published in the journal Annals of Internal Medicine, show that, compared with older adults with a good sense of smell, those with poor nasal discernment were at a 46 per cent higher risk for death at 10 years and 30 per cent at 13 years.
Professor Honglei Chen, an epidemiologist who’s focused his research on the sensory deficit in older adults, said: ‘Poor sense of smell becomes more common as people age, and there’s a link to a higher risk for death.
‘Our study is the first to look at the potential reasons why it predicts a higher mortality.’
Using figures from the National Institute on Ageing in the US, Prof Chen and his research team reviewed information from almost 2,300 participants aged between 71 and 82 over a 13-year period.
The participants included men and women, black and white people, who completed a smell test of 12 common odours.
Researchers then classified participants as having good, moderate or a poor sense of smell.
Prof Chen said the results were minimally affected by sex, race or other demographic and lifestyle factors.
But he said the surprising revelation was that the healthier participants at the start of the study were found to be largely responsible for the higher risk.
Prof Chen said poor sense of smell is known as an early sign for Parkinson’s disease and dementia and is associated with weight loss.
However, those conditions only explained 28 per cent of the increased risk, leaving most of it unexplained.
Prof Chen, of Michigan State University, said: ‘We don’t have a reason for more than 70 per cent of the increased risk.
‘We need to find out what happened to these individuals.’
He says that poor sense of smell may be an ‘early and sensitive’ sign for deteriorating health before it’s even recognised in the doctor’s office.
Prof Chen said: ‘It tells us that in older adults, impaired sense of smell has broader implications of health beyond what we have already known.
‘Incorporating a sense of smell screening in routine doctor visits might be a good idea at some point.’
Prof Chen added that if someone believes they are having trouble smelling, they should talk to a doctor.
He added: ‘It’s always prudent to talk to a physician about your health concerns.’