Researchers from Rush University Medical Center in Chicago discovered that the more everyday odours a person can identify, the more likely they are to be alive several years later. They found that having difficulty identifying familiar smells in old age could be associated with an increased risk of death.
The researchers gave more than 1,000 volunteers, aged between 53 and 100, a standard 12-item smell test.
"We used a scratch and sniff test for each odour where the participant had a choice of four options, the Daily Mail quoted study leader Dr Robert Wilson as saying.
"The odours were fairly familiar such as smoke, lemon, black pepper, chocolate and cinnamon," he added.
The researchers then followed the participants, none of whom had dementia or Parkinson's disease at the time, for four years.
During this period, 321 individuals or 27.6 per cent died.
Amazingly, they found that the risk of death was 36 per cent higher for those who only got six of the answers correct compared to those who managed to identify 11 out of 12. This association was true even when age, disability, depression, brain dysfunction and leisure activity was taken into account.
"The results indicate that difficulty identifying familiar odours in old age is associated with increased risk of death," Dr Wilson said. The study appears in January's edition of the journal Chemical Senses.