FORTUNE – Those who carry a gene variant associated with the strongest risk of Alzheimer’s disease may lose their ability to detect smells before they begin to lose cognitive function, according to a new study published Wednesday in the journal Neurology.
Those who carry a gene variant associated with the strongest risk of Alzheimer’s disease may lose their ability to detect smells before they begin to lose cognitive function—a potential sign of more severe disease to come.
That’s according to a new study published Wednesday in the journal Neurology, by researchers at the University of Chicago.
Researchers followed more than 1,000 older U.S. adults for 10 years, testing their genes, as well as their ability to smell and think at various intervals.
Those who carry the APOE e4 gene variant—which has the strongest known association with developing the disease—began to struggle to detect smells between ages 65-69, a decade before those without the mutation. Both cognition and the ability to identify odors later declined more rapidly in carriers than non-carriers.
Those with the variant were nearly 40% less likely to have good odor detection at any given point in the study than those without the variant.
Given the results, “testing odor sensitivity may be useful to predict future impaired cognitive function,” the authors wrote.The study used data collected from the National Social Life Health and Aging
Project, which did not track whether participants eventually developed Alzheimer’s, Dr. Matthew GoodSmith, an internist at the University of Chicago and lead author on the study, told Fortune.
Still, the results “definitely suggest testing sense of smell as a potential diagnostic tool, or maybe as part of a battery of tools used to assess someone’s risk of developing full-blown Alzheimer’s disease,” he said …