An inability to correctly identify familiar odors may be an early indication of the onset of Alzheimer’s disease, researchers report.
Dr. Robert S. Wilson told Reuters Health that difficulty identifying odors seems to be related the buildup of 'tangles' in the brain that appear early in the development of Alzheimer’s disease. “We found the correlation of difficulty identifying familiar odors with Alzheimer’s disease pathology even in people without dementia,” he added.
As reported in the January issue of the Journal of Neurology, Neurosurgery and Psychiatry, Wilson of Rush University Medical Center, Chicago, and colleagues performed brain autopsies on 129 elderly people who had died while participating in a memory and aging study.
The average age at time of death was 87.5 years. All of the subjects had undergone a standard 12-item Brief Smell Identification Test and had achieved correct scores ranging from 0 to 12.
After allowing for factors such as age and sex, the researchers determined that the density of tangles in the brain increased as correct smell scores went down.
“The results imply that trouble identifying familiar odors is a very early sign of Alzheimer’s disease,” concluded Wilson, “and that olfactory testing may be helpful in early identification of affected people.”
