A stressful family environment can impact a child's immune system, according to a study from a research group at the School of Health Sciences at Jönköping University and the Faculty of Health Sciences at Linköping University in Sweden.

Our immune system plays a large role in protecting our body against bacteria and viruses. At odds with our immune system is stress. While we are able to manage brief, "everyday stress," a long-term increase in stress or particularly stressful event can negatively impact our immune system, according to a press release announcing the findings.

The study, published in the Journal of Immunology, shows that children with high-stress family situations had a high level of cortisol, which is a biological marker of stress. The study also provided evidence that these high stress levels found in the children negatively impacted their immune system. Instead of protecting the body, the immune system reacted to substances in the body that should be left alone, which could provide evidence of an autoimmune reaction.

"Children within the high-stress group showed high level of cortisol, but low level of C-peptide, compared with the control group (p < 0.05). This supports the hypothesis that psychological stress may contribute to an imbalance in the immune response but also to a pathological effect on the insulin-producing β cells," the study found.

Researchers asked the parents of 5-year-old children questions regarding stress and prospective difficulties that had impacted the family, such as divorce or unemployment. The answers to these questions allowed the researchers to group the children by probable stress levels, while maintaining a control group of children who presumably grew up with "normal" stress levels.

"These young people can themselves report negative experiences in their daily lives and also negative experiences during their childhood" said Maria Faresjö, professor at the School of Health Sciences, who will also lead a continued research project.

The continued research will focus on young people in the 18 - 22 age group.