Even after a mild infection, the overall size of the brain had shrunk, researchers found.
Scientists found significant differences in MRI scans before and after infection.
There were losses in grey matter in the olfactory areas, linked to smell, and regions linked to memoryBut the researchers do not know whether the changes are reversible or truly matter for health and wellbeing. But the number of people infected with the more recent Omicron variant reporting this symptom has fallen dramatically.Paula Totaro lost her sense of smell when she caught Covid, in March 2020.
"And that connection between what's in the external world and what goes into your brain and your mind is what is being exercised." UK Biobank chief scientist Prof Naomi Allen said: "It opens up all sorts of questions that other researchers can follow up about the effect of coronavirus infection on cognitive function, on brain fog and on other areas of the brain - and to really focus research on how best to mitigate that."