COVID loss of smell: A sign of Alzheimer’s?

If COVID-19 took away your sense of smell, you’re not alone! Research shows more than 27 million people have experienced COVID-related smell or taste loss.

About 5% of COVID patients worldwide have reported loss of smell that lasts longer than six months.

“We don’t really understand why that happens. We believe it’s due to some inflammatory response of the smell nerve that occurs in these patients,” said Dr. Justin Turner, Associate Professor of Otolaryngology-Head and Neck Surgery at Vanderbilt University Medical Center.

While this side effect of the virus can be annoying, researchers are finding it may also be a predictor for cognitive decline in some people.

New findings presented at the Alzheimer’s Association international conference suggest there might be a link between loss of smell during COVID and cognitive decline. Researchers followed 766 adults ages 55 to 95 after their COVID infection. They found two-thirds of those infected had some type of cognitive impairment at the end of that year. In half of the participants, the impairment was severe.

In another study, unrelated to COVID, researchers found that a decline in sense of smell can predict loss of cognitive function and be a warning sign of structural changes in areas of the brain important in Alzheimer’s and dementia.

While more research is needed to confirm the relationship between loss of smell and brain health, doctors say the good news is most people with COVID do recover.

“It appears that the majority of patients get their smell function back within a couple of weeks,” Turner said.

Turner said while there are no sure ways to bring smell back, systemic corticosteroids given early on may help. And, doctors are also using a method called olfactory retraining where patients smell different scents to retrain their nerves as a possible solution for smell recovery.