Social inequalities accelerate biological aging

Biological aging does not always follow the pace of time. Some people age faster than others, and this phenomenon is closely linked to the social conditions in which they live. A thorough analysis of 140 studies involving over 65,000 individuals reveals that people from disadvantaged backgrounds or marginalized groups experience faster cellular aging. This process, measured by tools called epigenetic clocks, shows that social inequalities leave a lasting imprint on health.

Epigenetic clocks are algorithms that assess biological age by analyzing chemical modifications in DNA. They make it possible to distinguish a person’s actual age from the state of their body. Early versions of these clocks were remarkably accurate at estimating chronological age but struggled to reflect health differences between individuals. More recent versions, however, incorporate indicators related to mortality and physical decline. They thus capture the effects of living conditions on the body much more effectively.

The analysis shows that people in economic precarity or from ethnic minorities exhibit accelerated aging compared to those with better social conditions. This gap is particularly pronounced with third-generation epigenetic clocks, designed to measure the rate at which the body deteriorates over time. Among these, tools named DunedinPoAm and DunedinPACE, as well as GrimAge, prove the most sensitive to social disparities. The results indicate that children growing up in modest families age faster biologically, a phenomenon that persists into adulthood.

Ethnic differences also play a role. In the United States, Black individuals exhibit faster biological aging than White individuals, a gap also observed, to a lesser extent, between Latino people and White people. These disparities are partly explained by the accumulation of stress, unfavorable environmental exposures, and unequal access to healthcare. The latest generation of epigenetic clocks, which assess the rate of physical decline rather than absolute age, reveal these gaps with increased clarity.

Researchers emphasize that these tools could help understand how social inequalities become embedded in the body. They also pave the way for early interventions to limit the damage caused by unfavorable environments. However, their use raises questions about the representativeness of the data, which is still too often focused on affluent populations in wealthy countries. To refine these measurements, it will be necessary to expand studies to include more diverse social and geographical contexts.

Our References

Original Reference

DOI: https://doi.org/10.1038/s41562-026-02477-6

Title: Social determinants of health and epigenetic clocks: a systematic review and meta-analysis of 140 studies

Journal: Nature Human Behaviour

Publisher: Springer Science and Business Media LLC

Authors: Y. E. Willems; A. D. Rezaki; M. Aikins; A. Bahl; Q. Wu; D. W. Belsky; L. Raffington