Think Living Through The COVID-19 Pandemic Aged You Faster? You Might Be Right

Dealing with challenging times can make us feel we’ve aged decades in just a few months. The last five years of the COVID-19 pandemic certainly qualify as challenging times for most, and a new study is suggesting that that feeling of rapid aging might be more than just a feeling. If these results are borne out, the pandemic literally aged people’s brains – even those who didn’t actually catch COVID. 

As you might expect from such bombshell findings, experts are already differing in their interpretations, but one thing they can seemingly agree on is that this study merits a very close look. 

The team, led by Dr Ali-Reza Mohammadi-Nejad of the University of Nottingham, trained machine learning models on data from over 15,000 healthy participants in the enormous UK Biobank dataset. They then applied the trained models to the analysis of brain scans from a further 996 people. 

These 996 were split into two groups. The control group (564 people) had their brains scanned twice before the pandemic. The “Pandemic” group (432 people) had their brains scanned once pre-COVID, and once after the start of the pandemic. 

By comparing the two scans for each person, the researchers were looking for any evidence of changes that might indicate accelerated brain aging. This included observing changes in gray and white matter volume.

In the Pandemic group, there were noticeable differences in the pre- and post-COVID scans, suggesting more rapid brain aging. Even in those who had not actually caught COVID at the time of their second scan, this was evident – in other words, it wasn’t the disease itself that was at fault. Rather, the authors suggest, the isolation, disruption, and stress people experienced during 2020 could have altered their brains.

"Our findings provide valuable insight into how the COVID-19 pandemic affected brain health," the authors write, "demonstrating that the general pandemic effects alone, without infection, exerted a substantial detrimental effect on brain health [...] in a healthy middle-aged to older population."

That’s not to say that SARS-CoV-2 infection had no impact. Those with a history of infection between their scans showed decreases in certain cognitive abilities such as processing speed, which were not seen in those without infection.  

Before you give in to panic, it’s important to understand what these results don’t tell us, and the limitations of a study like this. 

“While this is a very carefully conducted analysis, we have to be cautious with interpretation,” commented Professor Masud Husain of the University of Oxford for the Science Media Centre. Husain was not a member of the study team but is a professor of neurology and cognitive neuroscience.

“The brain age difference between the two groups (as indexed by brain scanning) was on average only 5 months, and difference in cognitive performance between groups was only on the total time taken to complete one of the tests. Is this really going to make a significant difference in everyday life?”

Living through the early days of a pandemic was, at best, stressful for pretty much all of us – it stands to reason that would have some deeper impact on our bodies, but that doesn’t mean it has to be catastrophic.

The study authors themselves pointed out that the aging signatures they observed might not be permanent. In a statement seen by IFLScience, senior author Professor Dorothee Auer said, “We can’t yet test whether the changes we saw will reverse, but it’s certainly an encouraging thought.”

The findings in people who caught COVID are perhaps more instructive. Scientists have long accepted that COVID-19 goes way beyond a typical respiratory infection and can involve many body systems, including the brain.

“Among those infected with COVID-19, the increased brain age correlated with lower scores in a test of thinking skills like attention and problem-solving. This might help explain why some people who had COVID-19 have impaired cognition,” commented Dr Maxime Taquet, also of the University of Oxford, to the Science Media Centre.

Taquet added that “it is also possible that the observed association is primarily biological, driven largely by undetected infections.” Asymptomatic infections with SARS-CoV-2 are more common than was understood in the early days of the pandemic, and the patchy availability of testing likely means that a lot of infections went undetected. Perhaps those without a documented history of infection in this study did have COVID at some point after all.

The findings add to the growing body of knowledge of how global crises like pandemics can impact our health, even beyond the direct effects of the disease itself. The authors conclude that while more research is still needed, it’s vital that we learn these lessons to do whatever we can to combat these effects next time around.

The study is published in Nature Communications.