People carrying the genetic variant associated with the risk of Alzheimer’s disease would lose their ability to detect odors earlier than people who do not carry this genetic variant, we learn in a study published in review Neurology.
Early detection of the disease
“Testing a person’s ability to detect odors can be a useful way to predict future cognition problems,” said lead author Dr Matthew GoodSmith of the University of Chicago (USA). ‘study.
“While further research is needed to confirm these findings and determine what level of smell loss would predict Alzheimer’s risk, these results may be promising, particularly in studies aimed at identifying people at risk for early dementia. of disease.”
For this study, the researchers recruited more than 865 people and tested both their ability to detect an odor and their ability to identify the odor they smelled. The thinking and memory skills of these people were also tested twice, five years apart. Finally, DNA samples provided researchers with information about carriers of the gene associated with an increased risk of Alzheimer’s disease.
A loss of sense of smell from the age of 65
The findings of the study indicate that carriers of the gene variant are 37% more likely to have a loss of smell. And they begin to suffer from mild anosmia between the ages of 65 and 69.
Thinking and memory skills were similar between the two groups at the start of the study. But as expected, those who carried the gene variant experienced faster declines in thinking skills over time than those who did not. “Identifying the underlying mechanisms will help us understand the role of smell in neurodegeneration,” said Dr. Matthew GoodSmith at theAmerican Academy of Neurology.
Source : Association of APOE ε4 Status With Long-term Declines in Odor Sensitivity, Odor Identification, and Cognition in Older US AdultsNeurology, July 2023