One's ability to identify different smells may impact longevity

In a recent study of older adults, those with a reduced ability to identify certain odors had an increased risk of dying during an average follow-up of 4 years. The mortality rate was 45% in participants with the lowest scores on a 40-item smell test, compared with 18% of participants with the highest scores.

The study included 1169 Medicare beneficiaries who scratched and sniffed individuals odorant strips and chose the best answer from 4 items listed as multiple-choice.

"The increased risk of death increased progressively with worse performance in the smell identification test and was highest in those with the worst smelling ability, even after adjusting for medical burden and dementia," said Dr. Davangere Devanand, lead author of the Annals of Neurology study. "This was a study of older adults—the question that remains is whether young to middle-aged adults with impaired smell identification ability are at high risk as they grow older."