Study suggests toxic people, in fact, really age us faster

A new study finds that “toxic” relationships don’t just drain your energy, they may actually accelerate biological aging.

Everyone knows that toxic people can make life harder. The passive-aggressive coworker or the family member who drains your emotional energy can leave you feeling mentally exhausted. But what if those relationships are doing more than ruining your mood? Emerging research suggests that the stress caused by difficult social ties may also have measurable effects on the body, potentially accelerating the biological aging process.

The study

We know that your close friends have a role in defining your future, but a new study published in the journal Proceedings of the National Academy of Sciences of the United States of America examined whether negative social relationships with what researchers called “hasslers” might influence how quickly people age biologically. The research, led by sociologist Byungkyu Lee of New York University, analyzed data from more than 2,300 participants in Indiana as part of a large social-health survey.

Instead of relying on self-reported health outcomes, the researchers used advanced biological tools known as DNA methylation–based epigenetic clocks. These clocks measure patterns in DNA that reflect biological aging or the wear and tear on the body that may differ from a person’s actual chronological age. Two of the most advanced clocks used in the study, GrimAge2 and DunedinPACE, are widely used in aging research because they can estimate both the cumulative burden of aging and the rate at which someone is aging.

Participants were asked to map out their close social networks and identify individuals who made their lives more difficult. These “hasslers” included people who created persistent conflict, emotional strain, anger, or ongoing stress. Researchers then compared these social dynamics with biological aging indicators measured from saliva samples.

The study’s premise is based on decades of stress research. Chronic psychological stress activates the body’s stress-response systems, raising levels of hormones such as cortisol and increasing inflammation throughout the body. Over time, this persistent activation can contribute to what scientists call allostatic load, the accumulated physiological toll of long-term stress exposure.

The results

The findings of this study suggest that toxic social ties are common. But are we shocked? In the study, about 28.8% of participants reported having at least one “hassler” in their close social network, while roughly 10% reported having two or more. When researchers analyzed the biological data, they learned that each additional toxic relationship was associated with a roughly 1.5% faster pace of biological aging.

On average, participants who reported toxic individuals in their social networks had a biological age about nine months older than people of the same chronological age without those stressful ties. The type of relationship also mattered. Interestingly, toxic friends and family members showed stronger associations with accelerated aging than toxic spouses.

Researchers speculate that marriage can provide emotional benefits, such as companionship and reduced loneliness, that may offset some of the negative effects of conflict. Another key finding: toxic relationships were linked to higher inflammation levels and a greater risk of multiple health conditions. Chronic inflammation is already known to play a role in a wide range of diseases, including cardiovascular disease, diabetes, and certain autoimmune disorders.

The study also found that women were more likely to report at least one hassler in their network, and individuals who felt heavily dependent upon others were also more likely to have stressful relationships. In other words, some people may be more structurally vulnerable to toxic social dynamics than others.

The researchers caution that the findings show strong associations rather than definitive causation. It’s possible that people in poorer health may also experience more interpersonal stress, or that personality traits influence both conflict and health outcomes. Still, the consistency of the biological markers suggests the connection is meaningful.

Why this matters

For years, we’ve been told about the health and mental benefits of strong social relationships. Positive friendships and supportive family ties are associated with better mental health, longer life spans, and reduced risk of chronic illness. And while it’s not always easy to spot the red flags in our relationships, what this study looks at is the flip side: not all relationships are good for us. Negative relationships may operate as chronic stress exposures, but unlike major life events, these stressors can be subtle and persistent.

And because these interactions often occur within close relationships, they can be difficult to escape. The implications go beyond mental health advice. If toxic relationships truly contribute to accelerated biological aging, then social environments may be an underappreciated factor in long-term health outcomes. For men, who are statistically less likely to seek emotional support, this research underscores the importance of evaluating the quality of their social circles.