A Cornell University study found that lifelong social bonds can slow biological aging. Using DNA-based epigenetic clocks, researchers showed that people with deep, consistent friendships have younger cellular profiles and lower inflammation levels.
Can strong friendships actually help you stay young? A new study from Cornell University suggests they just might — not just emotionally, but biologically.
Researchers have found that people with deep, long-lasting social connections show slower biological aging at the cellular level. Using advanced “epigenetic clocks,” which measure changes in DNA to estimate biological age, scientists discovered that individuals with richer social networks and lifelong emotional support appeared biologically younger than their actual age.
The study, published in the journal Brain, Behavior, and Immunity – Health, analyzed data from over 2,100 adults who participated in the long-running Midlife in the United States (MIDUS) study.
Social Connections That Build Over a Lifetime
Lead researcher Anthony Ong, a psychology professor at Cornell, and his team coined the term “cumulative social advantage” to describe the lifelong accumulation of supportive relationships — from parental warmth in childhood to friendships, community involvement, and faith-based connections in adulthood.
“Cumulative social advantage is about the depth and breadth of your relationships over time,” Ong explained. “It’s how your social world expands and deepens throughout life that really shapes your health trajectory.”
The researchers found that people with stronger lifelong social support had slower epigenetic aging and lower levels of chronic inflammation, a key driver of diseases like heart conditions, diabetes, and neurodegeneration.
Friendship as a Biological Shield
Two key biological markers — known as GrimAge and DunedinPACE — revealed that those with sustained friendships and emotional support aged more slowly than those with weaker social ties. These measures are among the strongest predictors of overall lifespan and health.
Interestingly, while social advantage was linked to reduced inflammation (notably lower levels of the molecule interleukin-6), it had little connection to short-term stress hormones like cortisol. This suggests that long-term emotional stability may play a stronger role in cellular health than short-term stress responses.
It’s Not Just About Having Friends — It’s About Staying Connected
Unlike earlier research that looked at isolated factors like marital status or social activity, this study viewed relationships as a lifelong network of support. “It’s not just about having friends today,” Ong said. “It’s about how those connections have evolved and grown over decades. That accumulation shapes your biological health in measurable ways.”
The findings emphasize that consistent and meaningful relationships can act as a protective layer for the body — potentially as powerful as healthy eating or regular exercise in slowing aging.
The “Retirement Account” of Social Life
Ong compared social connections to saving for retirement:
“The earlier you start investing and the more consistently you contribute, the greater your returns,” he said. “Those returns aren’t just emotional; they’re biological.”
In other words, maintaining friendships and nurturing social bonds doesn’t just make life happier — it could actually make it longer and healthier.
As this study highlights, aging gracefully may depend not only on what we eat or how we move, but also on how well we stay connected — to friends, family, and community.
