A new study from researchers in the United Kingdom has found that the coronavirus may cause long-term brain loss and could be the reason some COVID-19 patients lose their sense of smell and taste.
"In short, the study suggests that there could be some long-term loss of brain tissue from COVID, and that would have some long-term consequences," former FDA Director Scott Gottlieb, MD, said on CNBC's The News with Shepard Smith.
"You could compensate for that over time, so the symptoms of that may go away, but you're never going to regain the tissue if, in fact, it's being destroyed as a result of the virus," said Gottlieb, who is also a CNBC contributor.
According to the study, researchers in the United Kingdom had access to brain image testing on about 40,000 people that was done before the start of the coronavirus pandemic.
In 2021, they asked hundreds of those people to come back for more brain scans. Almost 800 responded. Of those patients, 404 had tested positive for COVID-19, and 394 had usable brain scans that were taken before and after the pandemic.
Comparison of the before-and-after brain scans found "significant effects of COVID-19 in the brain with a loss of grey matter" in parts of the brain connected to smell and taste.
"All significant results were found in the primary or secondary cortical gustatory and olfactory areas, in the left hemisphere, using grey matter information (volume, thickness)," the study found.
Loss of smell and taste is one of the hallmarks of a COVID-19 infection. Research shows it can continue up to 5 months after the virus first strikes.
"The diminishment in the amount of cortical tissue happened to be in regions of the brain that are close to the places that are responsible for smell," Gottlieb said. "What it suggests is that the smell, the loss of smell, is just an effect of a more primary process that's underway, and that process is actually shrinking of cortical tissue."
CNBC. "New Covid study hints at long-term loss of brain tissue, Dr. Scott Gottlieb warns."
MedRxiv. "Brain imaging before and after COVID-19 in UK Biobank."