When the Body Says No: The Cost of Hidden Stress (6 page)

“Never. In fact, I love being asked. Almost never have I said yes with deep regret. I like doing things, I like taking things on. All somebody has to do is ask me and they got me.”

“What about since the cancer?”

“I’ve learned to say no—I say it all the time. I want to live! I think saying no plays a big role in getting better. Four years ago they gave me a 15 per cent chance of survival. I made a conscious decision that I wanted to live, and I set a timeline somewhere between five and seven years.

“How do you mean?”

“Five years is supposed to be the magical thing, but I know it’s just an arbitrary timeline. I figure I’ll cheat and get two more years. Then, after seven …”

“Are you saying that after seven years you can go back to living crazily again?”

“Yes, I might. I don’t know.”

“Big mistake!”

“Probably—we’ll talk about that. But right now I’m a good boy. I really am. I say no to everybody.”

The experience of stress has three components. The first is the event, physical or emotional, that the organism interprets as threatening. This is the stress stimulus, also called the
stressor
. The second element is the processing system that experiences and interprets the meaning of the stressor. In the case of human beings, this processing system is the nervous system, in particular the brain. The final constituent is the stress response, which consists of the various physiological and behavioural adjustments made as a reaction to a perceived threat.

We see immediately that the definition of a stressor depends on the processing system that assigns meaning to it. The shock of an earthquake is a direct threat to many organisms, though not to a bacterium. The loss of a job is more acutely stressful to a salaried employee whose family lives month to month than to an executive who receives a golden handshake.

Equally important is the personality and current psychological state of the individual on whom the stressor is acting. The executive whose financial security is assured when he is terminated may still experience severe stress if his self-esteem and sense of purpose were completely bound up with his position in the company, compared with a colleague who finds greater value in family, social interests or spiritual pursuits. The loss of employment will be perceived as a major threat by the one, while the other may see it as an opportunity. There is no uniform and universal relationship between a stressor and the stress response. Each stress event is singular and is experienced in the present, but it also has its resonance from the past. The intensity of the stress experience and its long-term consequences depend on many factors unique to each individual. What defines stress for each of us is a matter of personal disposition and, even more, of personal history.

Selye discovered that the biology of stress predominantly affected three types of tissues or organs in the body: in the hormonal system, visible changes occurred in the adrenal glands; in the immune system, stress affected the spleen, the thymus and the lymph glands; and the intestinal lining of the digestive system. Rats autopsied after stress had enlarged adrenals, shrunken lymph organs and ulcerated intestines.

All these effects are generated by central nervous system pathways and by hormones. There are many hormones in the body, soluble chemicals that affect the functioning of organs, tissues and cells. When a chemical is secreted into the circulation by one organ to influence the functioning of another, it is called an endocrine hormone. On the perception of a threat, the hypothalamus in the brain stem releases corticotropin-releasing hormone (CRH), which travels a short distance to the pituitary, a small endocrine gland embedded in the bones at the base of the skull. Stimulated by CRH, the pituitary releases adrenocorticotrophic hormone (ACTH).

ACTH is in turn carried by the blood to the adrenals, small organs hidden in the fatty tissue on top of the kidneys. Here ACTH acts on the adrenal cortex, a thin rind of tissue that itself functions as an endocrine gland. Stimulated by ACTH, this gland now secretes the corticoid hormones
(corticoid, from
“cortex”), the chief among them being cortisol. Cortisol acts on almost every tissue in the body one way or another—from the brain to the immune system, from the bones to the intestines. It is an important part of the infinitely intricate system of physiological checks and balances by which the body mounts a response to threat. The immediate effects of cortisol are to dampen the stress reaction, decreasing immune activity to keep it within safe bounds.

The functional nexus formed by hypothalamus, pituitary and adrenal glands is referred to as the
HPA axis
. The HPA axis is the hub of the body’s stress mechanism. It is implicated in many of the chronic conditions we will explore in later chapters. Because the hypothalamus is in two-way communication with the brain centres that process emotions, it is through the HPA axis that emotions exert their most direct effects on the immune system and on other organs.

Selye’s triad of adrenal enlargement, lymphoid tissue shrinkage and intestinal ulcerations are due, then, to the enhancing effect of ACTH on the adrenal, the inhibiting effect of cortisol on the immune system and
the ulcerating effect of cortisol on the intestines. Many people who are prescribed cortisol-type drugs in treatment for, say, asthma, colitis, arthritis or cancer are at risk for intestinal bleeding and may need to take other medications to protect the gut lining. This cortisol effect also helps to explain why chronic stress leaves us more susceptible to developing intestinal ulcers. Cortisol also has powerful bone-thinning actions. Depressed people secrete high levels of cortisol, which is why stressed and depressed postmenopausal women are more likely to develop osteoporosis and hip fractures.

This cursory description of the stress reaction is necessarily incomplete, for stress affects and involves virtually every tissue in the body. As Selye noted, “A general outline of the stress response will not only have to include brain and nerves, pituitary, adrenal, kidney, blood vessels, connective tissue, thyroid, liver, and white blood cells, but will also have to indicate the manifold interrelations between them.”
⁴
Stress acts on many cells and tissues in the immune system that were largely unknown when Selye was conducting his pioneering research. Also involved in the immediate alarm response to threat are the heart, lungs, skeletal muscles and the emotional centres in the brain.

We need to mount a stress response in order to preserve internal stability. The stress response is non-specific. It may be triggered in reaction to any attack—physical, biological, chemical or psychological—or in response to any
perception
of attack or threat, conscious or unconscious. The essence of threat is a destabilization of the body’s homeostasis, the relatively narrow range of physiological conditions within which the organism can survive and function. To facilitate fight or escape, blood needs to be diverted from the internal organs to the muscles, and the heart needs to pump faster. The brain needs to focus on the threat, forgetting about hunger or sexual drive. Stored energy supplies need to be mobilized, in the form of sugar molecules. The immune cells must be activated. Adrenaline, cortisol and the other stress substances fulfill those tasks.

All these functions must be kept within safe limits: too much sugar in the blood will cause coma; an overactive immune system will soon produce chemicals that are toxic. Thus, the stress response may be understood not only as the body’s reaction to threat but also as its attempt to maintain homeostasis in the face of threat. At a conference on stress at the National Institutes of Health (U.S.), researchers used the
concept of the stable internal milieu to define stress itself “as a
state of disharmony or threatened homeostasis.”
⁵
According to such a definition, a stressor “is
a threat, real or perceived, that tends to disturb homeostasis.”
⁶

What do all stressors have in common? Ultimately they all represent the absence of something that the organism perceives as necessary for survival—or its threatened loss. The threatened loss of food supply is a major stressor. So is—for human beings—the threatened loss of love. “It may be said without hesitation,” Hans Selye wrote, “that for man the most important stressors are emotional.”
⁷

The research literature has identified three factors that universally lead to stress:
uncertainty, the lack of information and the loss of control.
⁸
All three are present in the lives of individuals with chronic illness. Many people may have the illusion that they are in control, only to find later that forces unknown to them were driving their decisions and behaviours for many, many years. I have found that in my life. For some people, it is disease that finally shatters the illusion of control.

Gabrielle is fifty-eight, active in a local scleroderma society. Her naturally large eyes are magnified by the effect of her skin being stretched tightly on her face, her smile a barely perceptible movement of her lips over perfect white teeth. Her narrow fingers shine with the waxy translucency characteristic of scleroderma, but they also display some of the deformity of rheumatoid arthritis. Several digits have “drifted” off centre and are swollen at the joints. Gabrielle was diagnosed with scleroderma in 1985. Usually the disease’s onset is slow and insidious, but the first symptoms she experienced came on with flu-like suddenness—probably because in her case the scleroderma is associated with a more generalized rheumatic arthritis. “I was very, very ill for close to a year,” she recalls.

“The first five or six months I was hardly able to get out of bed. It was an effort to get up and do anything because of pain everywhere there is a joint. I would respond to an anti-inflammatory or Tylenol 3 for maybe three or four weeks. Then it wouldn’t be effective any more, so we would change and try something else. I was unable to eat. In five weeks I lost thirty pounds. I was down to ninety-one pounds…. I had read in different articles that people who come down with scleroderma are those who’ve always had to feel in control. All my life I’d been the
one in charge, taking care of everything. Suddenly now with the disease you are totally out of control.”

It may seem paradoxical to claim that stress, a physiological mechanism vital to life, is a cause of illness. To resolve this apparent contradiction, we must differentiate between
acute stress
and
chronic stress
. Acute stress is the immediate, short-term body response to threat. Chronic stress is activation of the stress mechanisms over long periods of time when a person is exposed to stressors that cannot be escaped either because she does not recognize them or because she has no control over them.

Discharges of nervous system, hormonal output and immune changes constitute the flight-or-fight reactions that help us survive immediate danger. These biological responses are adaptive in the emergencies for which nature designed them. But the same stress responses, triggered chronically and without resolution, produce harm and even permanent damage. Chronically high cortisol levels destroy tissue. Chronically elevated adrenalin levels raise the blood pressure and damage the heart.

There is extensive documentation of the inhibiting effect of chronic stress on the immune system. In one study, the activity of immune cells called natural killer (NK) cells were compared in two groups: spousal caregivers of people with Alzheimer’s disease, and age- and health-matched controls. NK cells are front-line troops in the fight against infections and against cancer, having the capacity to attack invading micro-organisms and to destroy cells with malignant mutations. The NK cell functioning of the caregivers was significantly suppressed, even in those whose spouses had died as long as three years previously. The caregivers who reported lower levels of social support also showed the greatest depression in immune activity—just as the loneliest medical students had the most impaired immune systems under the stress of examinations.

Another study of caregivers assessed the efficacy of immunization against influenza. In this study 80 per cent among the non-stressed control group developed immunity against the virus, but only 20 per cent of the Alzheimer caregivers were able to do so. The stress of unremitting caregiving inhibited the immune system and left people susceptible to influenza.
⁹
Research has also shown stress-related delays in tissue repair. The wounds of Alzheimer caregivers took an average of nine days longer to heal than those of controls.

Higher levels of stress cause higher cortisol output via the HPA axis, and cortisol inhibits the activity of the inflammatory cells involved in wound healing. Dental students had a wound deliberately inflicted on their hard palates while they were facing immunology exams and again during vacation. In all of them the wound healed more quickly in the summer. Under stress, their white blood cells produced less of a substance essential to healing.

The oft-observed relationship between stress, impaired immunity and illness has given rise to the concept of “diseases of adaptation,” a phrase of Hans Selye’s. The flight-or-fight response, it is argued, was indispensable in an era when early human beings had to confront a natural world of predators and other dangers. In civilized society, however, the flight-fight reaction is triggered in situations where it is neither necessary nor helpful, since we no longer face the same mortal threats to existence. The body’s physiological stress mechanisms are often triggered inappropriately, leading to disease.

There is another way to look at it. The flight-or-fight alarm reaction exists today for the same purpose evolution originally assigned to it: to enable us to survive. What has happened is that we have lost touch with the gut feelings designed to be our warning system. The body mounts a stress response, but the mind is unaware of the threat. We keep ourselves in physiologically stressful situations, with only a dim awareness of distress or no awareness at all. As Selye pointed out, the salient stressors in the lives of most human beings today—at least in the industrialized world—are emotional. Just like laboratory animals unable to escape, people find themselves trapped in lifestyles and emotional patterns inimical to their health. The higher the level of economic development, it seems, the more anaesthetized we have become to our emotional realities. We no longer sense what is happening in our bodies and cannot therefore act in self-preserving ways. The physiology of stress eats away at our bodies not because it has outlived its usefulness but because we may no longer have the competence to recognize its signals.