Scientists have known for years that major and minor life stresses interfere with immune function and contribute to disease. Stressful life events increase your susceptibility to several types of infections, from the common cold to tuberculosis, and to auto-immune disorders in which your body's immune system attacks its own cells. The death of a spouse or a child causes a profound drop in immune function which may explain why the death rate among men soars by almost fifty per cent during the six-month period after losing a wife. Research done at Harvard and at Ohio State University found that college examinations cause a measurable decline in immune function which may last for several weeks.
Although you may not be able to control all the stressors in your life, there are many steps you can take to build your immune resistance in the face of stress. Clear thinking, supportive social relationships, moderate exercise, adequate sleep, and immune-boosting nutrients can keep you from becoming a victim of stress. Let's examine these in more detail:
(1) Clear thinking. The emotional impact of a stressful event is determined by the way you think about it. We humans have a tendency to catastrophize relatively small setbacks, giving them more weight than they deserve. "Cognitive restructuring" is the name given to a psychological strategy that allows us to re-evaluate our stressors and gain perspective. Cognitive restructuring forms the psychological basis for all the great religions and is central to the philosophy of Buddhism. Non-religious methods have been developed and popularized by psychologist Albert Ellis (Rational Emotive Therapy) and psychiatrist Aaron Beck (Cognitive Behavior Therapy).
(2) Social ties. Isolation kills people, increasing the death rate from infection, heart disease and cancer. Involvement with others builds immunity. A California research team studied people suffering from melanoma, a highly malignant form of skin cancer. They found that involvement in a cancer support group improved survival and increased the activity of a group of white blood cells called natural killer cells, which are an important component of the body's defense against cancer. Harvard researchers found that students could improve immune function simply by watching a video about Mother Theresa's compassionate work among the poor of Calcutta.
(3) Rest and exercise. Exercise of modest intensity, like brisk walking thirty minutes a day, improves immune function and mood, prevents migraines, lowers blood pressure and decreases the disability that affects inactive people as they age. Both your level of activity and your general level of fitness are important. The federal government's Centers for Disease Control and Prevention estimates that a quarter million deaths per year in the United States can be prevented by regular physical activity at this level of intensity.
Your sleep is an active time during which your body restores itself. Sleep deprivation of experimental animals increases susceptibility to viral and bacterial infection, and, in humans, insomnia reduces natural killer cell activity. Healthy young men awakened from sleep between three and seven A.M. show a thirty per cent dip in natural killer activity the next morning. The natural sleep requirement of adults varies from as little as six to as much as ten hours per day, with most people needing seven to nine hours, preferably without interruption. Daytime relaxation also has important health benefits. A period of quiet meditation each day may lower blood pressure, relieve anxiety, improve nighttime sleep, and decrease the discomfort of chronic headache and other painful conditions.
(4) Nutrition and herbs. The leading cause of immune deficiency, worldwide and within the United States, is poor nutrition. Study after study has found that vitamin and mineral supplements improve immune function among the elderly and among children with recurrent infections. The specific nutrients with the most profound effects are the omega-three essential fatty acids (EFAs) which are found in flax seed and in fish, zinc, vitamin A, vitamin B6, folic acid, vitamin C, vitamin E, zinc, selenium and iron.
Restricting unhealthy dietary fat is also important for building resistance. The activity of natural killer cells is enhanced by low fat diets and diminished by high fat diets.
If you are highly stressed and prone to developing repeated infections, immune stimulating herbs may be a helpful addition to a nutritious diet. These iclude Echinacea species (a native American herb), Astragalus root (a component of traditional Chinese medicines, and shiitake and reishi mushrooms,which are used in contemporary Chinese medicine as Fu Zheng remedies, which means they "support the normal", stimulating health, rather than being used as medication to treat sickness. A dose which stimulates immune responses is 900 mg per day of each. For people with severe allergies, it is advisable to use reishi alone, as reishi may inhibit allergic reactivity and shiitake may increase it.