A new study funded by the U.S. National Institute on Aging and published in PNAS reports that difficult social ties can speed up the body’s biological aging. Analyzing saliva samples with DNA markers among approximately 2,300 participants aged 18 to 103, researchers found that for every additional “hassler” a person regularly interacts with, the pace of biological aging increased by about 1.5%. The authors linked that rise to approximately nine months of additional biological age. The effect was cumulative, according to USA Today.
How to define toxic people
In the study, “hasslers” or “toxic” people were defined as acquaintances, relatives, colleagues, or friends who consistently create tension, negative emotions, or anxiety, making life difficult. Roughly 28.8% to 30% of people reported having at least one such person in their social network. Family members—especially parents and children—were more likely to be identified as hasslers than partners or spouses. Among non-kin relationships, co-workers and roommates were more likely to be cited than friends. The strongest links to accelerated biological aging emerged from close ties such as friendships or family relationships rather than romantic partners, and spouses showed no significant association with biological aging, possibly due to a blend of positive and negative interactions.
“Not all social ties are supportive,” said lead author Byungkyu Lee. He noted that some friendships can be ambivalent. Co-author Brea Perry described some ties as “exclusively stressful,” The Washington Post reported.
Researchers observed that persistent exposure to hasslers functions as chronic stress that activates the body’s stress response and releases cortisol. Over time, that sustained stress leads to cumulative biological wear and tear, contributing to inflammation. This inflammation is associated with a range of health issues, including heart disease and diabetes. The presence of hasslers was also linked to adverse mental and physical health outcomes such as depression, anxiety, and higher body mass index. These conflicts, emotional stress, and a lack of social support exert direct effects on health and well-being.
Negative social ties
The burden of negative social ties fell disproportionately on individuals facing greater social and health vulnerabilities and on women more than men. Women typically reported having more hasslers, potentially because they are more likely to perceive and internalize the problems of others. Individuals in poorer health were also more likely to report difficult ties. More broadly, loneliness and social isolation carry substantial consequences for population health and are linked to 871,000 deaths per year globally.
Two people of the same chronological age can have significantly different biological ages. Because factors that accelerate biological aging are of keen scientific interest, blocking or reducing these accelerants may help extend healthy lifespan. Experts suggest practical steps to mitigate the harms associated with hasslers: set clear boundaries, limit time spent with those who consistently provoke tension, and invest in supportive relationships that can buffer stress.