November/December 2001
HEALTH BYTES

Immunity is affected by stress

Both short-term and long-term stress can hurt immune function, according to a recent study. The study focused on 33 healthy patients who had root canals, with another14 patients to form a control group. In the study, researchers drew blood samples from participants before, during and after their root canal treatments to measure levels of cortisol, a stress hormone, and the activity of natural killer cells, which play an important role in guarding the body against infection. In addition, study participants completed questionnaires and diaries to record their levels of pain and stress. During the study, 13 of the dental patients developed an illness, compared to two in the control group. Those who developed an illness showed lower natural killer-cell activity 30 minutes after treatment than those who had remained healthy. Researchers suggest those changes were a result in part of stress of the treatment.