What Stress Does to the Immune System
What Stress Does to the Immune System; Psychological stress produces a wide range of effects on the body, including increases in the risk of chronic back pain, diabetes, appendicitis, upper respiratory infections, arthritis, herpes, gum disease, common colds, and some forms of cancer. How can stress produce so broad a range of disabling effects? Answer: By compromising the body’s immune system, the first line of defense against illness.
The immune system is a complex surveillance system that fights bacteria, viruses, parasites, and other “non-self” substances that invade the body. The system contains more than a trillion specialized white blood cells called lymphocytes that circulate throughout the bloodstream and secrete chemical antibodies. These shark-like search-and-destroy cells protect us 24 hours a day by patrolling the body and attacking trespassers. The immune system is also equipped with large scavenger cells that zero in on viruses and cancerous tumors. Serving as a “sixth sense” for foreign invaders, the immune system continually renews itself. For example, during the few seconds it took to read this sentence, your body produced ten million new lymphocytes.
Today, many health psychologists specializing in psychoneuroimmunology (PNI) (psycho for the mind, neuro for the nervous system, and immunology for the immune system), study the connections among the brain, behavior, psychological states, the immune system, health, and illness. Before we get into some of the fascinating results, let’s pause for a moment and consider three of the methods these researchers use to spy on the operations of the immune system. One method is to take blood samples from animal or human participants exposed to varying degrees of stress and count the number of lymphocytes and other white blood cells circulating in the bloodstream.
A second is to extract blood, add cancerous tumor cells to the mix, and measure the extent to which the natural killer cells destroy the tumors. A third method is to “challenge” the living organism by injecting a foreign agent into the skin and measuring the amount of swelling that arises at the site of the injection. The more swelling there is, the more potent the immune reaction is assumed to be.
