If you are not a regular reader of the 21st Century Tech Blog, I have had COVID-19 twice. The first time occurred before any vaccines existed. I developed a heart condition, atrial fibrillation (A-Fib), when the virus infected the Left Atrium, one of the two upper chambers. It also caused Long COVID, leaving me in a brain fog that lasted almost six months. I stopped writing this blog during that period.
I recovered, and two years later, with vaccines up to date and the virus appearing to be in retreat, I went with my wife on holiday to the Caribbean. We upgraded our airplane tickets to business class to minimize exposure, wore our masks throughout the flight, and five days later, we had COVID again. Of the two weeks we were on holiday, a week was spent isolated in our hotel room, cleaning it, changing the bedding, and meals and sheets delivered outside our door. The local doctor saw us virtually, advising us to fly home, even if we were still testing positive. When we finally emerged, we were too exhausted to enjoy the last remaining days of our vacation. Getting back on the horse became hard, with us not flying again until last summer.
COVID-19 has changed humanity dramatically. Besides the more than 5 million people directly killed by the virus, and the millions more who died because the virus made them susceptible to other underlying conditions, COVID-19 changed how humans interacted in the face of isolation.
Now, two new studies have been published, one from the Harvard Medical School, and the second, involving a joint effort by researchers from the U.S., Sweden, Israel, Canada and the U.K., that suggest COVID-19 was even more problematic.
Harvard Study Shows The Pandemic Accelerated Brain Ageing
The first study looked at the brain health of 1,000 people during the pandemic, some infected and others not. The findings showed that structural changes to the brain, indicating accelerated ageing, happened whether individuals were infected or not. The changes were more noticeable in the elderly, in men, and disadvantaged people.
Were these changes reflected in cognitive decline? With those who were not infected, there was no evidence, but with those who contracted the virus, the answer is yes. This suggests that even if physical symptoms of brain ageing are present, it doesn’t necessarily lead to impaired memory or dementia.
How much had the brains aged during the pandemic when compared to the norm? The total was 5.5 months. The researchers concluded that over the five years of the pandemic, the virus did shape brains in vulnerable populations, but so did isolation, loss of employment and low income, as well as other health factors.
The researchers have called for further studies looking at ageing and brain function related to diseases that lead to pandemics. Their paper appeared in the July 22, 2025, edition of Nature Communications.
COVID-19 Study Linked To A Surge In Gut-Brain Disorders
A study comparing pre- and post-pandemic populations indicates gut-brain interaction disorders leading to increases in irritable bowel syndrome (IBS) and functional dyspepsia (FB). Using data sets collected between 2017 and 2023, the research is the first to do a population-wide comparison of gut-brain disorder rates before and after the pandemic. It revealed that incidents of IBS rose 28% and FB, 44%.
IBS is a chronic disorder that affects the gastrointestinal tract (GI), causing visible damage to the stomach and intestines. Estimated to affect between 10 and 15% of the human population, it is more prevalent in women, younger populations and in those living in cities. It is highest in Latin America and lowest in the Middle East. It is higher in low and middle-income countries, and regional diets, health care access and other factors are seen as contributors to it.
Dyspepsia is commonly known as indigestion. FB, however, is a chronic condition that causes pain, burning, bloating and early fullness when eating. It has no identifiable biochemical or structural cause. It is called functional because testing produces normal, or what gastroenterologists call, unremarkable findings.
The link to increased IBS may have more to do with reduced quality of life and increasing levels of depression and other mood disturbances associated with the period of the pandemic.
The research has been published in a paper released on July 30, 2025, in the journal Clinical Gastroenterology and Hepatology.
