Loss of smell from COVID-19 may increase dementia risk

Credit: CC0 Public Domain

Scientists from the University of Chicago found loss of smell from COVID-19 may create a future ‘dementia wave’.

They reviewed studies about the effect of COVID-19 on the olfactory system and whether loss of smell associated with COVID-19 infection may increase the risk of developing dementia later in life.

The research is published in the Journal of Neurophysiology and was conducted by Leslie M. Kay et al.

Loss of smell (anosmia) is one of the hallmark symptoms associated with the first wave of COVID-19 in 2020, with an estimated 77-85% of people infected with the virus reporting loss or alteration of smell (parosmia).

Although most people recover quickly from this dysfunction, an estimated 15 million people around the world are considered “smell long haulers” after otherwise recovering from COVID-19. They experience persistent anosmia or parosmia.

Studies have shown that the olfactory sensory epithelium—located in the upper area of the nose, close to where the olfactory nerve enters the olfactory bulb in the brain—carries a high viral load in people infected with SARS-CoV-2.

The olfactory bulb is the structure in the brain that manages the sense of smell and sends sensory information to other areas of the brain for processing.

These other brain regions are involved with learning, memory, and emotion.

Due to the proximity of the olfactory sensory epithelium to the olfactory bulb, COVID-19 infection could affect cognitive function even after recovery.

A link between a disrupted sense of smell and dementia has also been found in some people with neurodegenerative conditions such as Alzheimer’s and Parkinson’s disease.

Animal studies have shown that damage to the bulb results in anxiety and a depression-like

The review offers evidence that suggests inflammation introduced to the olfactory nerve and damage to the olfactory bulb via COVID-19 infection and immune response may also cause degeneration of brain structures connected to the olfactory system and cognitive impairment.

More research is needed and is possible due to the technological advances available to scientists during the current pandemic.

The team says while a catastrophe on many levels, the COVID-19 pandemic presents an opportunity to improve human health.

If you care about COVID, please read studies about the antibodies that block all the COVID-19 variants, and this anti-inflammatory compound may treat severe COVID-19.

For more information about COVID, please see recent studies about a major cause of COVID-19 death in older people, and results showing CBD from cannabis may help inhibit COVID-19.

Copyright © 2022 Knowridge Science Report. All rights reserved.