The study, funded by the National Institute on Aging and presented at the Alzheimer's Association International Conference in Toronto, shows that a decreased ability to identify odors correlates with dementia and Alzheimer's disease, and likely allows for the prediction of developing cognitive decline.
The people who developed the diseases showed low scores in odor identification testing.
"Our research showed that odor identification impairment, and to a lesser degree, entorhinal cortical thickness, were predictors of the transition to dementia," said Seonjoo Lee, assistant professor of clinical biostatistics in psychiatry at Columbia University Medical Center. "These findings support odor identification as an early predictor, and suggest that impairment in odor identification may precede thinning in the entorhinal cortex in the early clinical stage of Alzheimer's disease."
Currently, Alzheimer's disease can only be positively identified after it has reached the later stages, after the brain is already significantly damaged. Some 5.4 million Americans are thought to have Alzheimer's disease, according to the Alzheimer's Association.