Toxic relationships (especially in the family or at work) accelerate aging

The protagonist of The Anniversary, the award-winning novel by Italian writer Andrea Bajani, decides to separate himself from his parents, cut off all communication with them, to escape the distress caused by the relationship, irrevocably marked by the totalitarianism and persistent violence — both physical and emotional — exerted by his father. Unwittingly, with this distancing aimed at protecting his emotional well-being, this adult man is also buying himself a ticket to a longer and better life.

That, at least, is what the results of a recent study published in the journal PNAS suggest. It concluded that negative connections in a person’s close social network (those who routinely make life more difficult) are associated with faster biological aging. Specifically, the researchers found that each additional toxic person was linked to a modestly accelerated rate of aging and approximately nine months of additional biological age, as well as higher levels of inflammation, depression, anxiety, and a greater burden of chronic diseases.

Until now, the relationship between “unwanted loneliness” and accelerated aging had been extensively studied. However, for Byungkyu Lee, a professor in the Department of Sociology at New York University and lead author of the study, these findings shift the focus from the benefits of supportive relationships to the health costs of toxic relationships. “Much of the scientific literature has focused on social support as a protective factor, but our results suggest that negative bonds can also be biologically embedded, especially when they involve people who are central to daily life,” he explained to EL PAÍS.

For Consuelo Borrás, leader of the MiniAging research group at the INCLIVA Health Research Institute and author of 100 años no es nada (100 Years Is Nothing, 2026), the research results are “solid” and serve to reaffirm the importance of social relationships as a pillar of healthy aging, as important as diet, exercise, or sleep. “What makes this work especially valuable is that it measures biological aging with epigenetic clocks based on DNA methylation. It is the first study to quantify with this precision the specific effect of toxic relationships on biological aging,” she notes.

Stress as a driver of aging

In 2009, Australian biochemist Elizabeth Helen Blackburn received the Nobel Prize in Medicine (shared with Carol Greider and Jack Szostak) for the discovery of telomerase, an enzyme that adds DNA to the ends of chromosomes (telomeres), protecting them from degradation during cell division, and which plays a fundamental role in cellular aging and cancer development.

Five years earlier, as José Viña, professor of physiology at the University of Valencia, recalls, Blackburn had led research demonstrating how perceived life stress accelerated telomere shortening. This mechanism, according to the author of La ciencia de la longevidad (The Science of Longevity, 2025), is precisely what could underlie the link between toxic individuals and accelerated aging.

Lee shares this view, pointing out that difficult relationships can generate repeated tension and emotional strain that keep the body’s stress response systems activated over time. “When this happens repeatedly, it can affect inflammation, immune function, sleep, and other physiological systems closely related to aging,” the researcher says.

This reflection is also supported by Borrás, who emphasizes that sustained stress promotes a state of low-grade systemic inflammation, known as “inflammaging,” which is one of the hallmarks of aging. “The study itself finds higher levels of C-reactive protein in people with more toxic relationships, a chronic inflammation that alters DNA methylation patterns and leaves a detectable molecular footprint in our epigenome,” she adds.

What’s curious about the study’s results is that toxic close relatives (father, mother, brother, children, or in-laws) or toxic non-relatives like bosses or coworkers, show an impact on biological age that a toxic partner, however, does not. For Borrás, a possible explanation for this apparent contradiction lies in the relationships themselves. You can separate from a toxic partner. However, it’s more difficult to divorce parents, children, or a boss. “A conflictive relationship with a relative is more chronic, harder to avoid, and, above all, more ambivalent, combining emotional obligation and affective bond with conflict. The study shows precisely that ambivalent relationships are more damaging than exclusively negative ones. This combination of obligatory proximity and sustained tension seems to generate particularly toxic stress,” she explains.

For Lee, another explanation could lie in the fact that romantic relationships tend to combine negative and positive interactions in ways that differ from other types of relationships. “A spouse who causes you problems is also often someone with whom you share daily routines, resources, and emotional intimacy, which can offset the pattern we observe,” he suggests.

All the experts consulted agree that offsetting the impact of toxic people can also be achieved through a strong network of positive relationships and supportive connections. “Our findings suggest that the overall balance of a person’s social network matters, so having a wider circle of supportive people can help offset some of the stress caused by difficult individuals,” says Lee.

“Positive social support is known to reduce stress levels and modulate the inflammatory response; that is, it acts on the same biological pathways as toxic relationships, but in the opposite direction,” adds Borrás, for whom, if you can’t escape a toxic relationship, “it’s essential to invest in strengthening positive relationships.” José Viña also points out the importance of learning to manage stress emotionally: “If you can, distance yourself from that toxic person. And if you can’t distance yourself because, for example, it’s your father, don’t get angry and try to control your stress.”

What the researchers also agree on is the importance of avoiding alarmism. The results of this study cannot be summarized, for example, as “better alone than in bad company.” Unwanted loneliness, they remind us, is a well-established risk factor for accelerated aging, dementia, cardiovascular disease, and premature death. “What this study does tell us is that not just any company will do. A small but positive network can be much more protective than a large network riddled with toxic relationships. Neither loneliness nor bad company is good; what protects is the quality of the connection, not its mere existence,” concludes Borrás.

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