We talk a lot about the loss of smell with the Covid-19. But this can also be a sign of other pathologies, such as Alzheimer’s, for example. If a study had already looked into the question in 2011, a recent analysis revealed by a researcher from the National Institute of Scientific Researchin Canada, confirms this hypothesis.
Alzheimer’s disease, which currently affects 900,000 people in France, cannot be treated, but can be slowed down if it is detected very early on. Professor Charles Ramassamy, of INRS explained to Radio-Canada that “studies have confirmed that the dysfunction of olfactory identification would make it possible to distinguish cognitively healthy people from people who have a moderate cognitive deficit or who have Alzheimer’s disease“. A Chinese study from 2020 had also observed that patients with proven cognitive decline had more difficulty recognizing odors.
Detect the disease early to prevent its development
This symptom of altered and lost sense of smell could help predict the development of the memory disorder. The olfactory dysfunction would be located in the brain at the same level as the cognitive alterations of Alzheimer’s disease. The symptom is easier to detect, and manifests itself long before the memory loss : “Mechanisms in the brain could start 10, 20, 30 years before the first symptoms. The more we can identify early markers in time, the more we can turn on a little red light that will tell us to be careful and we can do additional tests to go further.“, underlined the doctor Ramassamy.
In 2011, the Journal of Neuroscience published research explaining that a weakened sense of smell could be a warning sign of Alzheimer’s. The conclusions of the study are always indicated on the site Fisher Center for Alzheimer’s research foundation. In 2017, another American study published in the journal Neurology showed that the participants who had the most difficulty recognizing smells were those with the most abnormal biomarkers of Alzheimer’s disease. “This is the first time that we have succeeded in clearly demonstrating that there is a direct link between the loss of the ability to recognize odors and the biomarkers that show the evolution of the disease.“underlined then Marie-Elyse Lafaille-Magnan, researcher at McGill University and lead author of the study.
- Odor identification as a biomarker of preclinical AD in older adults at ris, neurology2017.
- Journal of Neuroscience2011.
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