“Bullying is a common childhood experience that affects children at all income levels and racial/ethnic groups. Being a bully victim has long-term adverse consequences on physical and mental health and financial functioning, but bullies themselves display few ill effects. … [Copeland and colleagues] … show that victims suffer from greater increases in low-grade systemic inflammation from childhood to young adulthood than are seen in others. In contrast, bullies showed lower increases in inflammation into adulthood compared with those uninvolved in bullying. Elevated systemic low-grade inflammation is a mechanism by which this common childhood social adversity may …affect adult health functioning, even many years later.”

 
Copeland WE, Wolke D, Lereya ST, Shanahan L, Worthman C, Costello EJ: Childhood bullying involvement predicts low-grade systemic inflammation into adulthood. Proc. Natl. Acad. Sci. USA [Epub ahead of print, May 12, 2014; doi: 10.1073/pnas.1323641111 ].
http://www.pnas.org/content/early/2014/05/09/1323641111