A group of researchers in Argentina has determined that those who had a lingering loss of their sense of smell when suffering with covid-19 are more likely to also experience memory loss.

The research was conducted by Gabriela Gonzalez-Alemán at the Pontifical Catholic University of Argentina in Buenos Aires.

Gonzalez-Alemán and her colleagues analysed data from 766 adults aged 60 years or older who had no history of cognitive impairment. Each had taken a PCR test at a covid-19 testing clinic in northern Argentina, and nearly 90% tested positive.

A loss of smell is linked to Alzheimer’s and, following the dissemination of her research, Gonzalez-Alemán said: “There are lots of signs that make us think maybe the biological processes in covid-19 cognitive impairment could be the same in neurodegenerative disorders.”

The team of researchers also studied the severity of the covid-19 symptoms along with the effects after three months. Around two-thirds had some form of memory loss, with around half of this group finding it severe enough to affect their daily lives.

The findings support another growing theory in that covid-19 could enter the brain through the nose. Given that most brain cells lack the ACE2 receptor the virus normally uses to break into cells, direct infection of the brain is considered less likely than through some form of mechanism that targets cells in the nose, thus leading to the common loss of smell symptom in many covid-19 sufferers.

It has been proposed that the coronavirus can build tiny tunnels in nose cells, using these as a shuttle route through to brain cells where infection can then occur.

Gonzalez-Alemán stated she is looking to recruit more patients to further their research into this area to better understand the link between sense of smell and cognitive function.