Assessing older people’s sense of smell may assist in determining their risk for impending dementia or Alzheimer’s disease, according to a new study.

Of the nearly 600 study participants, who had average age of 80, those who were found to have difficulty identifying familiar odors at study onset developed mild cognitive impairment on follow-up, according to researchers at Rush University Medical Center, Chicago. The study subjects who made four errors on the odor identification test were 50% more likely to develop mild cognitive impairment than a person making just one error, investigators said.

Researchers used a 12-item “scratch and sniff” test to assess the seniors’ ability recognize familiar odors. They followed participants for up to five years to reassess for incidence of cognitive impairment.

Study results were published in the Archives of General Psychiatry.