Study in Twins Links Childhood Environment to Epigenetic Aging and Cognitive Decline

BUFFALO, NY — July 30, 2025 — A new #research paper was #published in Aging (Aging-US) on July 23, 2025, titled “Second generation DNA methylation age predicts cognitive change in midlife: the moderating role of childhood socioeconomic status.” In this study, led by Sophie A. Bell and Eric Turkheimer from the University of Virginia, researchers investigated how biological aging, measured through DNA methylation, is connected to changes in thinking skills during midlife and whether childhood socioeconomic status influences this relationship. Biological age provides a picture of how the body is aging that goes beyond simply counting years. In this study, researchers used both first- and second-generation DNA methylation clocks—tools that track chemical changes in DNA as markers of aging. GrimAge and PhenoAge, the second-generation clocks designed to reflect broader health and aging processes, were more accurate at predicting long-term changes in Intelligence Quotient (IQ) than the first-generation models that only estimated chronological age. The study analyzed 287 participants from the Louisville Twin Study, which is a long-term project that has followed twins from childhood into midlife. “DNAmAge was estimated with five commonly used algorithms, or epigenetic clocks (Horvath, Horvath Skin and Blood, GrimAge, and PhenoAge).” The results showed that twins with more rapid epigenetic aging had a larger drop in IQ scores. This pattern remained even after considering genetic background and early family environment, made possible by the twin-based design. Importantly, the relationship was strongest in twins who had grown up in families with lower socioeconomic status. This finding suggests that early-life disadvantage may make individuals more vulnerable to the effects of biological aging on brain health. This research adds knowledge to earlier work showing that childhood poverty can influence long-term health. It also highlights the value of second-generation epigenetic clocks as early indicators of brain aging. Unlike the first generation of clocks, these newer tools capture broader biological changes such as inflammation, disease risk, and behaviors like smoking. Although smoking partly explained the results because it strongly influences DNA methylation, it did not fully account for the association between accelerated biological aging and cognitive decline. This suggests that both life experiences and lifestyle factors shape body and brain aging. By combining decades of developmental data with a genetically informed twin design, the study provides new evidence that biological aging, especially when shaped by childhood adversity, is a key factor in midlife cognitive decline. These findings may inform early health strategies that consider both social and biological risks and support the use of second-generation methylation clocks to predict age-related cognitive changes. DOI - https://doi.org/10.18632/aging.206284 Corresponding authors - Sophie A. Bell - bvf7pa@virginia.edu, and Eric Turkheimer - ent3c@virginia.edu Video short - https://www.youtube.com/watch?v=vopDdS1olXw Sign up for free Altmetric alerts about this article - https://aging.altmetric.com/details/email_updates?id=10.18632%2Faging.206284 Subscribe for free publication alerts from Aging - https://www.aging-us.com/subscribe-to-toc-alerts To learn more about the journal, please visit our website at https://www.Aging-US.com​​ and connect with us on social media at: Facebook - https://www.facebook.com/AgingUS/ X - https://twitter.com/AgingJrnl Instagram - https://www.instagram.com/agingjrnl/ YouTube - https://www.youtube.com/@AgingJournal LinkedIn - https://www.linkedin.com/company/aging/ Bluesky - https://bsky.app/profile/aging-us.bsky.social Pinterest - https://www.pinterest.com/AgingUS/ Spotify - https://open.spotify.com/show/1X4HQQgegjReaf6Mozn6Mc MEDIA@IMPACTJOURNALS.COM