Dementia: Loss of smell may predict risk

Covid and dementia are linked in devastating ways. As type 1 spread through the population in 2020, nearly 25 percent (18,420) of those who died also had Alzheimer’s disease or another disease that causes dementia. Now, a new study has found another link and it could have implications for large swaths of the country.

The newly presented findings, which have not been published in a peer-reviewed journal, found that loss of smell during Covid may be a stronger predictor of cognitive decline, regardless of disease severity.

The preliminary findings, which qualifies experts for further research, were presented Sunday at the Alzheimer’s Association International Conference in San Diego.

Study co-author Gabriela Gonzalez Aleman, professor at Pontificia Universidad Catolica Argentina in Buenos Aires, said it was too early to tell if cognitive impairment was permanent.

The study followed 766 adults between the ages of 55 and 95 for a year after infection.

Read more: Dementia warning: New study links a popular drink in the UK to ‘impaired cognitive performance’

Nearly 90 per cent had a confirmed case of Covid and all completed regular physical, cognitive and neuropsychological tests over the course of one year.

Two-thirds of those diagnosed had some form of cognitive impairment at the end of that year. In half of the participants, the vulnerability was severe.

There are some limitations to the study. The researchers did not have solid data on the state of patients’ cognitive function before they contracted Covid in order to compare with the outcome at the end, but they asked the participants’ families about their pre-infection cognitive function and did not include people who had it. Perceptual impairment evident before the study.

The relationship between the loss of smell caused by the Covid virus and dementia requires further investigation, but evidence published elsewhere suggests that it is not a far-fetched idea.

do not miss
The popular drink in the UK is a ‘known’ cause of cancer [ADVICE]
Heart attack: an ear sign that can predict the event [TIPS]
“It’s a Terrible Death” illness killed Randy Newman [INSIGHT]

Alzheimer’s disease, which is characterized by memory loss, is one of the most common causes of dementia.

For the study, the team tracked 364 participants from the Baltimore Longitudinal Study of Aging (BLSA) over an average period of about 2.5 years. The BLSA study, led by the NIA, is the longest-running study of healthy aging in America.

Participants were initially cognitively normal and given baseline cognitive tests, odor identification tests, and a positron emission tomography (PET) scan, a type of brain imaging that can detect deposits of amyloid beta and tau associated with Alzheimer’s disease and related dementia.

During the study period, 17 participants, or five percent of all trackers, were diagnosed with mild cognitive impairment (MCI), including 11 cases associated with Alzheimer’s disease, three cases with vascular dementia, and one with frontotemporal dementia. Two were unspecified based on clinical characteristics.

The research team found that each score with lower performance on the odor identification test was associated with a 22 percent higher chance of developing mild cognitive impairment.

This relationship remained similar even after investigators adjusted for age, gender, race, education, olfactory test transcript, apoprotein E (APOE ε4) gene status, smoking, elevated depressive symptoms, and vascular disease.

Brain PET scans of this subgroup of participants showed that lower olfactory scores were associated with higher levels of Alzheimer’s disease in the brain, particularly in areas associated with the sense of smell, including parts of the orbitofrontal cortex, and areas important for memory and learning, such as the temporal lobe.

Furthermore, participants with reduced sense of smell over time had higher levels of amyloid and tau in some areas related to olfactory function and memory.

Amyloid and tau are two key proteins thought to interfere with communication between brain cells in some types of dementia.

Leave a Reply

%d bloggers like this: