Children may age faster when bullied or exposed to violence, according to a new study. Children who experience violence exhibit DNA wear and tear typical of adults, which could increase the risk of early disease onset and premature death, researchers said.
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Researchers compared a child's real age to their biological age gauged through telomeres that protect the ends of chromosomes and shorten as a person gets older.
Children exposed to violence, such as bullying or physical abuse, had shorter telomeres than unexposed children, researchers found. In addition, the more violence the children experienced, the shorter their telomeres were.
"Those kids are 'older' than they are supposed to be," Idan Shalev, study coauthor and a postdoctoral researcher at Duke University, told LiveScience.
Childhood trauma may have long-lasting effects that could manifest decades later in the form of health problems, Elissa Epel, an associate professor of psychology at the University of California, San Francisco, who wasn't involved in the study, told WebMD.
"Now we have some evidence that children's immune system aging can be adversely affected by severe stress early in childhood, a scar that could possibly last decades later," Epel said. "This study underscores the vital importance of reducing violent exposures for children -- both serious bullying and abuse in the family."
Shorter telomeres are linked to early death and an increased risk of chronic diseases such as diabetes, the researchers wrote. Guarding children against violence could be an effective way of curbing the number of people affected by chronic diseases.
"An ounce of prevention is worth a pound of cure," Terrie Moffitt, study coauthor and professor of psychology and neuroscience at Duke University, said in a statement. "Some of the billions of dollars spent on diseases of aging such as diabetes, heart disease and dementia might be better invested in protecting children from harm."
Thousands of children are bullied or exposed to violence every year, according to the Centers for Disease Control and Prevention. In a 2009 survey, the CDC found that approximately 20 percent of high school students reported being bullied on school property. In addition, the CDC found in a separate 2009 survey of almost 30,000 adults that 22 percent were physically abused at least once when they were a child.
Researchers remained uncertain how violence might shorten telomeres.
"We know that violence is associated with higher inflammation levels," Shalev told LiveScience. "Higher inflammation levels are associated with shorter telomere length."
Telomere shortening may be reversible, Shalev said. Studies have shown a healthy diet and physical activity is linked to longer telomeres, he said, along with meditation.
The journal Molecular Psychiatry published the study on Tuesday.
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