"Hasslers", or people in one's close social network who make life difficult, may have consequences on aging, with each additional hassler responsible for about 1.5 per cent faster speed of aging and nine month older biological age, a study has found.
Aging effects were found to be especially pronounced when a hassler is a family member. Women, daily smokers, people in poorer health and those with adverse childhood experiences are more likely to report having hasslers in their social networks.
Findings published in the journal Proceedings of the National Academy of Sciences (PNAS) showed that negative social ties are not rare within close relationships, with nearly 30 per cent of the participants reporting at least one hassler in their network.
"Importantly, exposure to negative social ties follows patterns of social and health vulnerability, with women, daily smokers, people in poorer health, and those with adverse childhood experiences more likely to report having hasslers in their networks," the authors wrote.
"Having more hasslers is associated with accelerated biological aging in both rate and cumulative burden: Each additional hassler corresponds to approximately 1.5 per cent faster pace of aging and roughly 9 mo (months) older biological age," they said.
The researchers also found that hasslers tend to occupy peripheral network positions and more likely to be connected through weak, uniplex relationships defined by a single type of interaction such as only business.
They added that hasslers do not on their own cause ageing processes — alternative mechanisms may be involved.
For example, individuals experiencing an accelerated biological aging may become more irritable, thereby eliciting more negative interactions, the team said.
Researchers, including those from New York University, looked at saliva samples of 2,345 people from the US state of Indiana, which were analysed for DNA methylation -- a process where a methyl group (-CH3) is added to a DNA molecule and is important for gene expression.
Abnormal patterns of DNA methylation are often found in diseases, including cancer.
The findings identify negative social ties as "chronic stressors" that can shape one's aging trajectory and underscore the need for interventions to reduce harmful social exposures to promote healthier aging, the authors said.
Chronic stress has been well-established to drive biological aging and influence gene expression and inflammation, they said.
The study used data from the Person-to-Person Health Interview Study (P2P), a statewide omnibus health survey conducted in Indiana.