Epigenetic aging clocks sped up during the COVID-19 pandemic in a 1,028-person German study

What the study did

A German team from the Max Planck Institute of Psychiatry, Bielefeld University and partners used an existing twin and family study that had already collected saliva DNA before the first COVID-19 containment measures in March 2020. They collected saliva again in 2021, after the second phase of measures. The sample included 1,028 people: 359 children (average age 9.5), 385 adolescents (average 15.5) and 284 adults (average 24.3).

They measured four epigenetic clocks, which estimate biological age from DNA methylation: DunedinPACE (pace of aging), GrimAge2, Horvath and PedBE (a clock designed for children). They then tested whether changes were linked to objective pandemic stressors, how burdened people felt, and risk factors present before the pandemic.

What it found

Epigenetic age acceleration rose significantly across all age groups on PedBE (b = 0.17) and GrimAge2 (b = 0.08), and pace of aging rose on DunedinPACE (b = 0.13), all with p < 0.0001. Poorer physical health before the pandemic and lower parental socioeconomic status were linked to larger increases. Objective pandemic stressors were not. In adolescents, feeling more burdened by the pandemic was linked to a larger rise in pace of aging (b = 0.04, p = 0.01).

What it does not prove

There was no comparison group that lived through the same period without a pandemic, so normal developmental change, sampling differences and other events cannot be fully separated from pandemic effects. The clocks were measured in saliva, and the participants were young, so we do not know whether the changes persist or relate to later disease. A faster clock reading is a biomarker shift, not a diagnosis.

The Youthful take

This study supports what many clinicians suspect: psychosocial stress may show up in biological aging markers, and adolescence may be a sensitive window. The more practical message is that baseline health and resources shaped who changed most. Aging clocks are most useful for tracking groups over time, and we treat any single person's clock result as one data point among many, not a verdict.