Covid pandemic may have sped up brain aging, even for those who never had it

(CN) — Living through the Covid-19 pandemic likely took more of a toll on global brain health than previously thought. Although the CDC says nearly 77% of Americans have contracted coronavirus, even those who didn’t catch the disease may not be safe from its side effects.

Since the virus was first discovered in late 2019, more than 704 million cases and 7 million deaths have been reported globally. While many cases develop into long or long-haul Covid, a condition that comes with a variety of lasting side effects such as fatigue and headaches, scientists theorized the impacts could run deeper.

Researchers from the University of Nottingham’s School of Medicine first obtained longitudinal brain scans from UK Biobank — scans from nearly 1,000 healthy adults taken at various times before and after the pandemic. The scans, analyzed in a study published Tuesday in Nature Communications, gave scientists “a rare window to observe how major life events can affect the brain,” said Stamatios Sotiropoulos, a co-lead author on the study and a professor of computational neuroimaging at the university.

Once all the brain scans were prepared for the researchers, a guessing game commenced: Using machine learning and advanced imaging, researchers estimated the “brain age” of each scan, or how old their brain appeared to be compared to the subject’s actual age. There was a clear pattern: Those who lived through the pandemic had consistently older brains, with a special emphasis on the brains of elderly people, men and those from “disadvantaged backgrounds.”

“What surprised me most was that even people who hadn’t had Covid showed significant increases in brain aging rates,” said Dr. Ali-Reza Mohammadi-Nejad, who led the study. “It really shows how much the experience of the pandemic itself — everything from isolation to uncertainty — may have affected our brain health.”

The study, supported by the National Institute for Health and Care Research, the Nottingham Biomedical Research Centre and the Medical Research Council DEMISTIFI program, showed that those who were infected with the disease in between brain scans had a noticeable decrease in cognitive abilities like mental flexibility and processing speed. However, researchers believe current data suggests a subject who never contracted Covid-19 may not face symptoms from their aged brain and that brain aging could even be reversible.

Dorothee Auer, a senior author on the study and a professor of neuroimaging at the university, emphasizes that the study’s findings show general brain health relies not only on actual physical health but also on the conditions of everyday environments and our quality of life.

“The pandemic put a strain on people’s lives, especially those already facing disadvantage,” said Auer. “We can’t yet test whether the changes we saw will reverse, but it’s certainly possible, and that’s an encouraging thought.”