Recent research shows those who had been hospitalized due to COVID-19 might already have a reduced sense of smell and taste, not just for the short term, but possibly for life.
Recent research shows those who had been hospitalized due to COVID-19 might already have a reduced sense of smell and taste, not just for the short term, but possibly for life.
In an observational study led by scientists from Oxford University (UK Biobank), brain scans of hundreds of individuals who had moderate to severe COVID-19 showed “significant and deleterious” effects on the gustatory and olfactory cortical systems. UK Biobank had already scanned more than 40,000 participants before the pandemic broke out, enabling them to invite people back in 2021 for a second imaging session.
The researchers compared before-and-after brain scans of 782 participants, 394 of whom had tested positive for SARS-CoV-2, while the remaining 388 had not had COVID-19 but were placed in a control group to match the sex, age, ethnicity and scan intervals of the positive group. All of the participants were over 45 years old.
Other factors that qualified the participants for the study included proximity to the testing clinic (living within 75 kms), consistent address (still living in the same site as when the first scan was taken), and had no incidental findings from their initial imaging session.
The comparisons showed that the virus made a noticeable effect on the brain with the loss of some grey matter in three areas: the left insula, the left lateral orbitofrontal cortex and the left parahippocampal gyrus.
Of the 394 who had COVID-19, the scientists then compared the brain scans of the 15 who had been hospitalized due to the virus and the 379 who had not. The comparison results were not significant overall, but they placed further weight on the findings from when the entire group’s scans were compared to the control group. What was observed in the 15 participants, however, was that a greater loss of grey matter in areas that were linked to the senses of taste and smell.
The study hasn’t been published yet, though it is already out in preprint format, and has made the rounds across various print and online channels. In an appearance on CBS’ “Face the Nation,” former Food and Drug Administration head Dr. Scott Gottlieb expressed concern over the findings, which he said suggested that COVID-19’s symptoms are persistent and could well go on through a person’s lifetime.
Meanwhile, Dr. Eric Holbrook, associate professor of otolaryngology at Harvard Medical School and rhinology chief at Mass Eye and Ear, cautions against making sweeping statements from one study alone. In an interview with the Boston Globe, Holbrook noted that the paper hasn’t been peer reviewed to date and the findings have yet to be vetted.
The study also acknowledges in its conclusion that it is the first longitudinal imaging study where COVID-19 patients had been scanned before they got sick with the virus.
