Study Suggests Pandemic May Have Accelerated Brain Aging

More than five years into the Covid-19 pandemic, the lingering after-effects are still coming to light. A recent study published in Nature Communications indicates that the pandemic may have contributed to accelerated brain aging, even in individuals who were never infected with the virus.

Researchers from the University of Nottingham analyzed brain images taken before and after the onset of the pandemic. Their findings suggest that the brains of individuals who experienced the pandemic showed signs of aging more rapidly than those scanned prior to March 2020.

“I think what surprised me the most was that even people who hadn’t had Covid showed significant increases in brain aging rates,” remarked Ali-Reza Mohammadi-Nejad, a coauthor of the study, in a statement. “It really demonstrates how the overall experience of the pandemic, including isolation and uncertainty, may have influenced our brain health.”

The research utilized data from the UK Biobank, which collects biological information from approximately half a million individuals over time. This dataset provided MRI scans for nearly 1,000 adults. Some participants had two scans before the pandemic, while others had one before and another after the health restrictions were implemented.

“The longitudinal MRI data from the UK Biobank offered us a rare opportunity to observe how such a significant life event could affect the brain,” stated Stamatios Sotiropoulos, a professor of computational neuroimaging at the University of Nottingham and a coauthor of the study.

To evaluate “brain age,” the researchers trained a machine-learning model on over 15,000 healthy volunteers without chronic illnesses. This model allowed them to determine how much older or younger a brain appeared relative to its actual age. The findings indicated that the pandemic group’s mean brain age was, on average, 5.5 months older than the control group.

The study also found this acceleration in brain aging was particularly pronounced among older individuals, men, and those from lower socioeconomic backgrounds, including those facing educational, employment, or health challenges.

“Our study highlights that brain health is influenced not just by illness but by the environment we live in,” noted Dorothee Auer, the lead author of the study. “The pandemic particularly strained the lives of those already at a disadvantage.”

While signs of brain aging were evident across the board, only those who had contracted Covid experienced measurable cognitive decline. The pandemic group who had Covid between the scans showed decreased performance in mental flexibility and processing speed tests. On the other hand, those who were not infected did not experience significant cognitive changes, suggesting that structural changes in the brain do not always lead to functional symptoms.

However, the authors acknowledged some limitations in their observational study that could affect the results. For instance, the time intervals between the scans varied between the two groups, and the UK Biobank may not fully represent the most marginalized communities in the UK.

The researchers also pointed out the potential for reversal, as their analysis was based on scans taken at only two specific time points. This means there might be room for neurological recovery in subsequent years. “We don’t really know yet if the changes can be reversed, but it’s definitely an optimistic thought,” Auer concluded.