Still, scientists weren't sure those changes actually led to poorer health. Now, they seem convinced. The JAMA paper points to the important role that compounds known as cytokines play in regulating the immune response. In some cases, they stimulate the release of other compounds essential for inflammation. In other cases, they maintain the balance of other components of the human immune response.
Researchers know that psychological stress can alter the level of certain hormones.
These alterations induced by stress are responsible for the changes in cytokine concentrations since stress hormones alter the synthesis and the release of the cytokines, the authors explained. They said that enough is known now to show that certain changes in lifestyle can increase a person's resistance to some infectious diseases. The researchers said doctors should focus more on the role stress plays in infections and diseases such as asthma, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, psoriasis and cancer.