People who lose their sense of smell in middle or old age are at an increased risk of dying early, a new study claims.
Researchers from Stockholm University in Sweden followed about 1,774 adults aged 40 to 90 years for 10 years. After controlling for demographic, health-related, and cognitive confounders, each additional correctly identified odour lowered the risk of mortality by 8 per cent, researchers said. About 23 per cent of the participants died.
Individuals who performed at chance level on tests (indicating complete olfactory loss) were at a 19 per cent higher risk of death than individuals with normal smell function, researchers said.
The results contribute to the growing evidence that olfactory assessments might provide insights on the ageing brain, researchers said.
"Our results were not explained by dementia, which was previously linked to smell loss. Instead, mortality risk was uniquely predicted by smell loss," said Jonas Olofsson, senior author of study published in Journal of the American Geriatrics Society.
"In our future research, we will try to pinpoint the biological processes that can explain this phenomenon," Olofsson added.