Bullied children may experience an increase of low-grade inflammation throughout the body that persists into adulthood, according to a recent study Reuters reported.

Researchers found that kids who are bullied tend to be sick more often than their peers and may have stomach aches, headaches and sleep problems.

"Our findings look at the biological consequences of bullying, and by studying a marker of inflammation, provide a potential mechanism for how this social interaction can affect later health functioning," William E. Copeland, lead author of the study and an associate professor of psychiatry and behavioral sciences at Duke University School of Medicine, said in a statement.

Copeland told Reuters his team is "pretty confident" this is a bullying effect. He added that inflammation might explain the connection between bullying and physical health.

For the study, researchers used data from the Great Smoky Mountains Study, a robust, population-based study that has gathered information on 1,420 individuals for more than 20 years. Individuals were randomly selected to participate in the prospective study, and therefore were not at a higher risk of mental illness or being bullied.

Participants were interviewed throughout childhood, adolescence and young adulthood, and among other topics, were asked about their experiences with bullying. Researchers collected blood samples from the participants to measure C-reactive protein (CRP), a marker of low-grade inflammation and a risk factor for health problems including metabolic syndrome and cardiovascular disease.

Based on their findings, young adults who had been both bullies and victims as children had CRP levels similar to those not involved in bullying, while bullies had the lowest CRP -- even lower than those uninvolved in bullying. Thus, being a bully and enhancing one's social status through this interaction may protect against increases in the inflammatory marker.

The findings suggest that bullying can disrupt levels of inflammation into adulthood, similar to what is seen in other forms of childhood trauma.

"Our study found that a child's role in bullying can serve as either a risk or a protective factor for low-grade inflammation," Copeland said. "Enhanced social status seems to have a biological advantage. However, there are ways children can experience social success aside from bullying others."

The researchers concluded that reducing bullying, as well as reducing inflammation among victims of bullying, could be key targets for promoting physical and emotional health and lessening the risk for diseases associated with inflammation.

The findings were recently published online in the Proceedings of the National Academy of Sciences.