STRESS AND CANCER
By Gabor Mate
More young people are being diagnosed with cancer in this country, according to a report released this past spring by the Canadian Cancer Society and the National Cancer Institute. Unfortunately, research into the causes of this disturbing trend will focus on the usual suspects while ignoring what likely is the most prevalent, single contributing factor: socially-induced, psycho-emotional stress.
Stress remains outside the frame of reference of mainstream medical thinking, despite its documented negative effects on the immune system and despite many studies that confirm an association between cancer and people's life stresses.
"Most people do not fully realize to what extent the spirit of scientific research and the lessons learned from it depend upon the personal viewpoints of the discoverers," wrote the great Canadian stress researcher, Hans Selye. "In an age so largely dependent upon science and scientists, this fundamental point deserves special attention." Stress is excluded from consideration by most clinicians and researchers precisely because in our society it is so ubiqutious as to be taken for granted. It is accepted as part of the normal scheme of things, not-as it really is-something foreign to the natural design and quite inimical to health.
It was Dr. Selye who first pointed out that stress of any sort, whether physical or emotional, has certain characteristic effects in the body, and in particular on the immune system. He noted that stressed laboratory animals had shrunken spleens, lymph glands and thymus glands, all important elements of the organism's immune functioning.
Since his pioneering work six decades ago, we have learned much more about the damaging impact of stress on the human hormonal system and immune apparatus. In fact, we have learned that the two are not separate systems at all: They comprise one system whose components are intricately interconnected with each other. This "super-system" also includes the nervous system and the brain's emotional centres. Nerve fibres electrically wire together all these crucial tissues and organs. Shared molecular messengers ensure that they all speak and understand the same chemical language. Factors, including psycho-emotional ones, affecting any one part of this super-system will exert effects in all parts of it. We can now map the complex pathways through which stress may contribute to the causation of many diseases, including cancers.
For example, the adrenal glands of chronically stressed people produce chronically elevated levels of cortisol, the body's prime "stress hormone." Cortisol exerts a powerful suppressor effect on immune functioning. It causes atrophy of the lymph organs and diminishes the numbers and the activity of immune cells essential in the defence against micro-organisms and tumour growth. It also inhibits the effect of the cancer-fighting chemicals produced by these cells.
A class of lymph cells called natural-killer (NK) cells is in the vanguard of the body's immune surveillance against cancer. Research has shown that women with breast cancer whose NK counts are low are at greater risk for metastatic spread of their malignancy. Research has also shown that NK cells decline with ongoing stress, as for example in medical students facing examinations. "It may be said without hesitation," Hans Selye wrote, "that for man the most important stressors are emotional."
Just how prescient he was is evident when we see that in this same study of medical students, those who were the loneliest had the poorest NK counts. In studies of the spousal caregivers of people with Alzheimer's disease, immune functioning was found to be significantly depressed, with the most socially isolated the most affected.
In the light of such findings-all readily available in mainstream medical publications-it is not surprising that a recent Australian study should have concluded that "women experiencing a stressor objectively rated as highly threatening, and who were without intimate emotional social support, had a ninefold increase in [the] risk of developing breast carcinoma." Nor is it surprising that men who are currently married-as opposed to previously married-are less likely to be diagnosed with metastatic cancer of the prostate.
Even a clearly identified enironmental carcinogen like tobacco smoke does not exert its effect without a contribution from stress. Smokers who are emotionally repressed, for example, and have trouble feeling and expressing anger, are much more likely to develop lung cancer. In fact, smokers who do not have that repressed emotional coping style do not seem at greater risk for lung cancers than non-smokers-although, of course, they are still much more prone to suffer from heart disease, emphysema, and a host of other ailments.
Many human cancers are hormone related, such as cancer of the breast or ovary or, in men, cancers of the prostate or the testicles. There is a well-known association between stress and hormones, as women know whose menstrual patterns are intimately.
The stresses of modern life have grown palpably more severe over the past several decades. For many people, there is also growing personal isolation following from the loosening of traditional social bonds. If we take to heart the lessons taught by Hans Selye, we will seek the causes of malignancy not only in what we ingest but also in how we have come to live our lives.
Stress reduction includes obvious measures such as healthy eating patterns, sleep hygiene and exercise. It also requires living a life that balances the physical, emotional and spiritual needs of human beings. Those are the three pillars of health; ignoring any of them leads to dis-ease and illness. The most difficult aspect of that triad is the psycho-emotional one, because for so many of us the driving dynamics of our psychic functioning operate in the difficult-to-see regions of the unconscious. Stress management, therefore, requires a careful and committed attention to what is not working in our lives, to what does not feel right. None of us need be victims, but to be actively and authentically in charge of our lives we need to take full responsibility for all aspects of our existence.
Gabor Mat is a Vancouver physician and author whose articles have appeared in the Globe and Mail.