Sense of Smell Linked to Dementia Risk
According to a long-term study involving nearly 3,000 adults between the ages of 57 and 85, seniors who cannot identify at least four out of five common odors are more than twice as likely to develop dementia within five years as those with a normal sense of smell.
For the study, researchers used "Sniffin'Sticks," which look like felt-tip pens, but are infused with a distinct scent instead of ink. They asked study participants to identify each scent – peppermint, fish, orange, rose, and leather – one at a time. About 78 percent had a normal sense of smell and correctly identified four or five of the scents, 18.7 percent correctly identified two or three of the scents, and 3.2 percent identified not more than one scent correctly.
The study results were recently published in the Journal of the American Geriatrics Society. The findings support earlier research suggesting that olfactory dysfunction is associated with an increased risk of death within five years and is a better predictor of death than heart failure, cancer, or lung disease diagnoses.