Friendships, community ties and family bonds may apply the brakes to natural cell aging, providing a simple way to invest in health in older age. In a massive new study, scientists have found that social connections are tied to slower biological aging and less chronic inflammation.
In an ambitious analysis of 2,117 adults in the Midlife in the United States (MIDUS) study, Cornell University researchers have found that lifelong investment in social bonds and connection – “cumulative social advantage” – is key to staying healthier longer.
“This paper builds on a foundational study we published last year showing how cumulative social advantage relates to positive health outcomes,” said first author Anthony Ong, psychology professor in the College of Human Ecology at Cornell University. “This new study digs deeper into the same data to understand the biological mechanisms – essentially, how social connections get under our skin to affect aging at the molecular level.”
The researchers created an overall score of “social advantage” based on factors like parental warmth in childhood, emotional and social support in adulthood, and community or religious involvement. They then compared that score with biological markers of health, including epigenetic clocks that estimate biological age, measures of inflammation and prevalence of stress hormones. What they found was that people with higher social advantage tended to show younger biological age on two of the most accurate clocks that are seen as predictors of morbidity and mortality – GrimAge and DunedinPACE – along with lower levels of interleukin-6 (IL-6), an inflammation marker linked to disease. These links remained even after accounting for differences in income, education and demographics.
“Cumulative social advantage is really about the depth and breadth of your social connections over a lifetime,” Ong said. “We looked at four key areas: The warmth and support you received from your parents growing up, how connected you feel to your community and neighborhood, your involvement in religious or faith-based communities, and the ongoing emotional support from friends and family.”
While they found that more social investment throughout life was linked to lower levels of IL-6, a molecule implicated in heart disease, diabetes and neurodegeneration, there were no significant associations with short-term stress markers like urinary cortisol. As such, the signal is stronger in long-term social investment rather than day-to-day stress that these sorts of engagements might come with.
And unlike studies that have looked at factors such as whether someone is married or the size of their social circle, this study suggests that it’s less to do with whether you are surrounded by friends now, but more about the social wealth you’ve built over the years. Every act of support, connection or belonging adds a small “deposit” to that account – and those cumulative investments seem to pay off biologically, protecting against the wear and tear of aging.
“What’s striking is the cumulative effect – these social resources build on each other over time,” Ong said. “It’s not just about having friends today; it’s about how your social connections have grown and deepened throughout your life. That accumulation shapes your health trajectory in measurable ways.”
It’s also worth noting that “cumulative social advantage” theory suggests that the benefits of support and connection build up over time, while their absence compounds negative health outcomes. But access to these social resources isn’t equal. Factors like race, class and education shape who grows up with supportive parents, who finds the communities where they feel a sense of belonging, and who experiences strong, healthy relationships in adulthood.
That means people with fewer social opportunities may also miss out on the biological protection those ties provide – potentially accelerating aging and increasing vulnerability to illness. While observational, this study nonetheless adds to the growing body of evidence suggesting that social life is not just a matter of happiness or stress relief but can meaningfully impact physiological health.
“Think of social connections like a retirement account,” he added. “The earlier you start investing and the more consistently you contribute, the greater your returns. Our study shows those returns aren’t just emotional; they’re biological. People with richer, more sustained social connections literally age more slowly at the cellular level. Aging well means both staying healthy and staying connected – they’re inseparable.”
Earlier studies have found that social isolation can have a direct impact on brain health, and that keeping those friendship and communities ties can help stave off neurodegeneration and other chronic illnesses.
The study was published in the journal Brain, Behavior, & Immunity – Health.
Source: Cornell University
