A SIMPLE smell test could reveal if you're at higher risk of dying in the next six years.
Loss of smell could predict future illness, signalling conditions such as and frailty, scientists said.
Previous research has shown that older adults with a have a higher risk of mortality, but the mechanisms behind this link have remained unclear.
Scientists from the Karolinska Institute in found that adults who frequently were more likely to die in the next six years – with their risk jumping by 6 per cent study each time they got it wrong.
Study participants were adults between the ages of 60 and 99 whose smelling skills were put to test with what's known as the Sniffin’ Sticks Odour Identification task.
They were given sixteen felt tip pens with distinct smells one after the other, and allowed to smell them for five seconds each.
The 2,524 participants were asked to name what they were smelling if they were able to.
Otherwise, they were given a multiple choice and asked to select the correct one out of four.
They got one point with each correct answer – so if someone were to name every single smell they'd get 16 points.
Participants were categorised as – smell blind – if they got six points or less.
Those who were able to correctly identify 11 to 16 smells were normosmic – meaning they had a normal sense of smell.
After 6 years, about 18 per cent of participants had died and 9 per cent had developed dementia.
After 12 years, 39 per cent had passed away and 15 per cent had the memory-robbing disease.
Researchers compared this information to their smell tests to assess their likelihood of dying after six and 12 years.
Each incorrect answer on the odour identification test was associated with a 6 per cent increased risk of death after six years, and with a 5 per cent increased risk at 12 years.
So if someone got a score of 6 on their smell test, they had a 42 per cent increased risk of death from any cause after six years and a 34 per cent increased risk at 12 years.
Researchers found that anosmic people had a 68 per cent higher risk of death after six years compared to normosmic participants.
For people who performed poorly on their smell test, dementia was the biggest risk factor for early death after six years, followed by .
At the 12 year mark, frailty became a bigger risk factor, scientists said.
“Dementia explained 23 per cent of the olfaction-mortality association at six years,” they wrote.
“However, this association was absent at 12 years.
“Frailty accounted for 11 per cent of the total association at 6 years and remained the only meaningful mediator at 12 years, accounting for 8 per cent of the total association.”
They concluded: “Overall, our findings reinforce olfactory deficits as a marker, rather than a direct contributor, to outcomes linked to increased mortality.”
Researchers said better understanding of the relationship between poor sense of smell and mortality could help find ways to improve the survival and quality of life for people with “olfactory deficits”.
