Especially the lack of social interaction during the lockdowns led to epigenetic changes in the genetic material of adolescents
© MPI Psychiatry
To the Point
- Epigenetic clocks: Researchers used epigenetic clocks to measure changes in DNA methylation, which affects gene activity and relates to aging and disease risk.
- Covid-19 stress and epigenetic aging: The Covid-19 pandemic caused stress that sped up biological aging at the DNA level, especially in adolescents.
- Findings in adolescents: Adolescents showed the strongest link between perceived pandemic stress-especially social isolation-and faster epigenetic aging, unlike children or adults.
Led by postdoctoral researcher Alicia Schowe at the Max Planck Institute of Psychiatry in Munich, an interdisciplinary collaboration between four German universities (Bielefeld, Bonn, Bremen, Saarland) investigated the biological correlates of pandemic-related stress using epigenetic clocks. These clocks measure age-related changes in DNA methylation, a chemical process along the DNA strand that regulates gene activity, and compare this to the pace of change that would be expected for someone’s chronological age. An increased pace of DNA methylation change in these epigenetic clocks has been linked to a higher long-term risk of developing diseases such as cancer or type 2 diabetes.
The team used data from the ongoing TwinLife Epigenetic Change Satellite project. This project recruited just over 1.000 participants in Germany, including children aged eight to ten, adolescents aged 14 to 16, and adults aged 20 to 29. The researchers collected saliva DNA samples from the participants, once before the first Covid-19 lockdown in March 2020, and once after the second lockdown in winter of 2021 until spring 2022. The team wanted to know: How did subjective stress measures (such as participants’ perceived pandemic burden and threat) and objective stress measures (such as regional incidence rates and lockdown policies) affect the participants epigenetic aging?
Accelerated aging
The results: The pandemic accelerated the pace of epigenetic aging among all participants. This change was most pronounced in participants who had poorer health outcomes before the pandemic. Interestingly, subjective and objective measures of stress – particularly perceived pandemic burden – played a significant role only among adolescents, not children or adults. The lack of social interaction was particularly significant for them.
The fact that they were not allowed to see their friends not only affected their mood but also left epigenetic traces in their bodies. “This suggests that adolescence may be a time period that is especially sensitive to the effects of stress – this could be due to the changes happening in the body during puberty, or because lockdown measures, like restrictions on seeing peers, had a particularly strong impact on this age group”, lead author Schowe explains. The changes in epigenetic aging observed in children and adults could be linked to other pandemic-related factors, like an increase in sedentary lifestyle.
Vulnerable groups
In more detailed analyses, the researchers wanted to explore which factors made participants particularly vulnerable to stress. “Across all age groups, stress was most significantly felt by those who were already at risk before the pandemic, whether due to poorer physical health, lower subjective well-being or lower socio-economic background”, says Elisabeth Binder, director at the Max Planck Institute of Psychiatry and senior author of the study. Notably, objective measures like incidence rates or lockdown measures did not predict the subjective, perceived stress reported by participants.
This is the first study to explore the impact of stress caused by the Covid-19 pandemic on epigenetic aging. It shows that societal crises may have measurable biological impacts, and that, in this case, these impacts disproportionately affected adolescents and populations that were vulnerable before the pandemic. Long-term follow-up studies are needed to determine whether this translates into an increased risk of illness for these populations in the future.
