Early life experiences may leave enduring marks on health that persist across decades and throughout the body, according to a study published on June 18 in the journal Science. Researchers from Arizona State University, Vanderbilt University, and collaborating institutions studied a group of free-living rhesus macaques to provide molecular evidence that early adversity imprints lasting changes at the epigenome—the biological layer regulating gene activity.
The research team analyzed DNA methylation patterns, which are markers of aging and can be used to estimate both chronological and biological age. Using data from 237 macaques living in semi-natural conditions on Cayo Santiago, Puerto Rico, researchers developed tissue-specific "epigenetic clocks" capable of predicting age within about one year. They found that aging-related changes in DNA methylation were highly dependent on tissue type.
"At a molecular level, aging looks very different depending on which tissue you examine," said Amanda Lea, assistant professor of Biological Sciences at Vanderbilt University and co-senior author. "Blood, which is most commonly measured in human studies, only captures part of the picture." Some tissues showed strong age-related patterns while others exhibited more subtle changes.
The study also examined how early life adversity—such as maternal loss or low social status—affected DNA methylation. "We found that each type of adversity tends to affect specific regions of the genome," said Lea. "But once it targets those regions, the effects are often shared across multiple tissues." The researchers identified thousands of genomic regions where methylation was associated with early adversity; however, these effects did not always align with accelerated aging.
"In some cases, adversity-related changes looked like accelerated aging. In others, they went in the opposite direction," explained co-lead author Rachel Petersen. This suggests that early adversity reshapes the epigenome in complex ways rather than simply speeding up biological aging.
The findings underscore the importance of studying multiple tissues when investigating how environmental exposures impact health over time. "Different tissues have their own epigenetic landscapes and respond differently to both age and adversity," said Baptiste Sadoughi, an ASU postdoctoral researcher. The use of rhesus macaques living in naturalistic social environments allowed for unique insights into how detailed life histories connect with molecular changes across body systems.
