The loss of sense of smell and Alzheimer’s are linked

News 17 August, 2017
  • Antoine Lacroix

    Wednesday, 16 August, 2017 22:42

    Wednesday, 16 August, 2017 22:42

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    The difficulty to recognize odors could be an early symptom to help scientists monitor the evolution of Alzheimer’s in people at risk of developing the disease, according to a study from McGill University.

    “This is the first time we can clearly demonstrate that there is a direct link between the loss of the ability to recognize odors, and biomarkers that demonstrate the evolution of the disease “, points out Marie-Elyse Lafaille-Magnan, phd student at McGill University and lead author of the study.

    Close to 300 people, with an average age of 63 years and whose parent had suffered from the disease, were submitted to recognition tests odors, such as smoke, lemon, and the ” bubble gum “.

    Lumbar punctures

    Also, 100 participants volunteered to undergo a “lumbar puncture to measure the levels of proteins linked to Alzheimer’s disease in cerebrospinal fluid,” says Mrs. Lafaille-Magnan.

    “The topics which have had the most difficulty recognizing the smells were those in which the biomarkers of Alzheimer’s disease were the most abnormal,” says Judes Poirier, co-author of the study and director of the research Programme on ageing, cognition and Alzheimer’s disease at the Douglas Institute.

    “Often, it was noticed among the participants that their brains had difficulty associating the smell with the object that it represented. For example, some felt the lemon, but responded that it was another fruit, ” continued Mr. Poirier.

    The discovery is important because scientists want to detect the disease before the first symptoms of memory loss appear, since the brain lesions are too advanced at this stage.


    “If you want to have an impact on the person, it is necessary to take before. This is where the test odour becomes interesting, ” says Judes Poirier.

    The recognition tests odors could help scientists monitor the evolution of the disease in people at risk.

    “There is no drug that can delay the disease or to reverse the trend,” says Mr. Poirier. We have tested at least 260 since 2003 and nothing is satisfactory. “

    “The recognition test odours might help to see the effects of the drugs that are put to the test “, argues Marie-Elyse Lafaille-Magnan.

    We are reminded, however, that the loss of smell can be linked to other medical problems as Alzheimer’s disease and that further research will be needed to confirm the discovery.