Violence and bullying early in life leave deep scars on children, causing significant changes even at the level of their chromosomes, according to a new study published in Molecular Psychiatry. Researchers examined the chromosomes of 236 children between the ages of five and 10. They also assessed the children for exposure to violence, including domestic abuse between the mother and partner, frequent bullying and physical mistreatment by an adult. The genetic analysis focused on the tips of the chromosome, called the telomeres. These regions of DNA are like the caps on the end of shoelaces, and keep the chromosome ends from fraying or sticking together. As we grow older, our telomeres naturally shorten, so they act as a rough sign of aging. In children who had experienced cumulative violence, the telomeres shortened more quickly than would happen with normal aging. This degradation was greatest for children exposed to two or more kinds of violence. "Children who experience extreme violence at a young age have a biological age that is much older than other children," researcher Idan Shalev told WebMD. The children were essentially aging seven to 10 years faster than normal. The increased erosion of the children’s DNA shows how violence during childhood has lifelong consequences, affecting the child’s health, brain and the way the brain functions. The children are also at risk for earlier onset of diseases related to aging as adults. This study not only provides a potential mechanism for how violence affects children throughout their lives, but also highlights the need to better protect them from that violence early on.