I. DO SMALL STRESSES REALLY MATTER?
When PNI (psychoneuroimmunology) researchers first turned from rats to human beings, they began by studying the effects of very intense events upon the immune system. Such studies included returning astronauts, Swedish volunteers who endured 77 hours of noise and sleep deprivation, and people who had recently lost a spouse. All of these tests demonstrated a laboratory verifiable decrease in immune function.
What about examinations taken by medical students? Studies have shown reduced immune function in these students during exam week. Medical students as 'professional students' are people skilled in taking exams and doing well. Yet, despite their relative competence in taking exams, exams consistently depressed immunological function.
Are exams in college a health hazard? Every day stresses are usually not a health hazard unless aggravated by other factors such as alcohol and drug abuse, poor sleeping habits, poor nutrition, and inactivity--all of which can depress immune function. One of the most persuasive demonstrations that emotional factors can indeed have a measurable affect on health appeared in 1991. In that study, volunteers were inoculated with measured doses of a common cold virus. Five different viruses were tested along with a placebo, a 'dummy' shot. As expected, many of the volunteers came down with colds and some did not. Among the volunteers injected with any of the five viruses, the chance of getting a cold or respiratory infection was directly proportional to the amount of stress the volunteers said they had experienced during the past year. The study was the first well controlled demonstration that stress can increase the risk of infection.
Do understand that stress is only one factor in determining infectious disease risk. The frequency with which you are exposed to viruses or bacteria is a major factor in infection. So does the overall status of your immune system. This becomes particularly important for older adults. Why? Immune function diminishes with age. Our best understanding at this point is that people most likely to become ill in response to stress are probably those whose immune systems are already compromised to some extent, either by a disease like AIDS or by a natural process like aging.
.....
II. LONG TERM CHRONIC STRESS
What happens when people are faced with a stressful situation that lasts months or years? The weight of evidence to date suggests that the immune system does not adapt well to chronic stress. The immune system seems to be active at a lower level in the face of chronic stress. Stress without relief is often faced by those caring for chronically ill elderly persons. A 1992 study showed that caregivers had a measurable decrease in three measures of cellular immunity as compared to non-caregivers. It was also found that caregivers with higher levels of social support had better immune function than those who reported less social support. (My note: elder care is an increasing problem as people live longer and live out those last years with chronic disease. Popular writers have dubbed an emerging cohort as the 'sandwich generation.' They are those people faced with college costs and care of an aging parent on top of trying to prepare for their own retirement.
.....
III. THE IMPORTANCE OF RELATIONSHIPS
Early in these articles, we cited the role of support groups in extending the lives of cancer patients. In similar fashion, some of the strongest evidence in the area of PNI now shows that poor personal relationships and lack of social support can adversely affect the immune system. In fact large, well controlled epidemiological studies have shown that stressful social relationships rivaled smoking, high blood pressure, high blood cholesterol, obesity, and physical inactivity as a risk factor for illness and early death. The immune system may be part of the connection that explains this link.
Studies of several diverse groups of research subjects have found that people who are lonely, as measured by psychological tests tend to have poorer immune function. On the flip side of this, Women with breast cancer who have supportive personal relationships demonstrate better immune function than those who are loners. Divorced persons with the most negative feelings about the separation or have the most difficulty 'letting go' of a former spouse tend to show the greatest downward regulation of the immune system. (My note: in a future unit we will see the health implications of 'being connected' in an Italian community with low heart disease rates and the classic health studies of British postal employees.)
.....
IV. CANCER AND AIDS
These are probably the most feared of all modern diseases. According to one widely held theory, cancer cells arise in the body throughout life, but they are held in check by immune cells that recognize them as nonself and destroy them. It is only when the immune system cells become ineffective that cancer spreads. As I write this, I am reminded of Mickey Mantle who was overwhelmed by cancer after being given immunosuppressant drugs following an organ transplant. Cancer quickly overwhelmed him.
Aids, the ultimate immunological disaster, results from wholesale destruction of the cellular immune system caused by a virus that invades and kills T-helper cells. What about 'guided imagery,' where patients consciously try to stimulate their immune system? Thus far there is no good evidence that it benefits people with cancer. A few recent studies, however, suggest that group therapy may improve certain components of the immune response and possible survival for people with certain kinds of cancer. Early studies show that stress management groups and exercise can help maintain immune function for persons with AIDS.
.....
V. A SUMMARY OF EVIDENCE FOR PSYCHONEUROIMMUNOLOGY
There is now a journal devoted to psychoneuroimmunology. It is Brain, Behavior and Immunity. Listed below is a summary of the evidence for PNI.
(1) Nerve endings have been found in the tissues of the immune system.
(2) Changes in the brain and spinal cord alter immune response which in turn alters brain and spinal cord activity.
(3) Changes in hormone and neurotransmitter levels alter immune responses. Similarly, immune responses affect hormone and neurotransmitter levels.
(4) Lymphocytes are chemically responsive to hormones and neurotransmitters.
(5) Lymphocytes can produce hormones and neurotransmiters.
(6) Activated lymphocytes, cells actively involved in an immune response, produce substances that can be perceived by the central nervous system (the brain and spinal cord).
(7) Psychosocial factors may alter the susceptibility to or the regression of autoimmune disease, infectious disease, and cancer.
(8) Immunological activity may be reduced by chronic stress.
(9) Immunological activity can be influenced by hypnosis.
(10) Immunological activity can be modified by classical condition as demonstrated in the experiments with saccharin.
..... CJ '98
Resource
Coleman, D. and Gurin, J. Mind-Body Medicine. Yonkers: Consumers Union, 1993.