How We Know What Isn't So (23 page)

What all of this boils down to is that we need to question whether our beliefs (about health or anything else) stem mainly from a sense of surface plausibility. The naturalness with which we base judgments on representativeness should lead us to be particularly concerned with beliefs that conform to the principle of “like goes with like.” It has been argued, for example, that this guiding assumption was partly responsible for people’s initial resistance to the germ theory of disease. It just did not seem plausible that a “big” effect like death and disability could stem from such a “little” cause as microscopic organisms. Causes often do resemble their effects, of course, but there are more than enough exceptions to warrant a little caution and a little healthy skepticism.

During the past twenty-five years, increasing numbers of people have sought alternatives or complements to conventional medical practice, alternatives that are often labelled “holistic” or “New Age.” These increasingly popular treatments merit special discussion for two reasons. First, in part because some holistic ideas are promoted by sober scientists and others by pop enthusiasts, it is often unclear what “holistic medicine” encompasses and what these alternative health practices offer. Second, because of this ambiguity as to exactly what constitutes the field of holistic health, it can be difficult to assess the merit of this growing trend. Are there benefits to be derived from these New Age ideas? Alternatively, does the very ambiguity of these approaches make any assessment of their effectiveness particularly vulnerable to the kind of errors and illusions discussed above?

What is holistic medicine? Most broadly, it is an orientation toward health and medicine that rejects or deemphasizes what is considered to be a materialistic and reductionistic bias on the part of conventional “Western” medicine. Orthodox medicine most often seeks to find the organic cause of a disease or dysfunction, and tries to alleviate it with some physical intervention like antibiotics or surgery. The emphasis is on the specific, local cause of the malady and how to fix it. Holists, on the other hand, are more inclined to consider psychological and even spiritual factors as either the cause or the remedy for a given condition. They emphasize the “whole person” rather than the local cause of the dysfunction, and many problems are thought to stem from a lack of “balance” among mind, body, and spirit. The
Journal of Holistic Medicine,
for example, states that its mission emphasizes “personal efforts to achieve balance.”

How then does one achieve physical, psychological, and spiritual balance? At its simplest, holistic medicine consists of a set of relatively uncontroversial preventive health practices such as maintaining a proper diet and getting sufficient exercise. The individual is urged to take responsibility for his or her own health, both in terms of adopting lifestyle practices designed to promote “wellness” and in the sense of making informed choices about the treatment of any illness. More directly relevant to the goal of achieving balance, many holists also promote the practice of meditation, yoga, biofeedback, and positive mental imagery. In addition to their purported ability to bring about harmony of mind, body, and spirit, these practices are also thought to reduce stress and thus lower one’s susceptibility to diseases considered to be psychological, social, or environmental in origin. The effectiveness of these techniques in meeting either goal, however, has been the subject of considerable controversy. Finally, the most questionable aspects of the field of holistic health are a set of bizarre practices, both ancient and new age, that are linked only through their rejection of and by conventional medicine. Included here are such practices as psychic diagnosis and psychic healing, palmistry, colonic irrigation, faith healing, and iridology (i.e., diagnosing disease anywhere on the body by examining spots on the iris of the eye). These practices are either based on principles that conflict with established knowledge, or have been shown by empirical research to be of absolutely no value (or both).

The “Up” Side of Holistic Medicine.
If we ignore these latter, demonstrably bogus interventions, there is surely some merit to both the underlying philosophy and many of the specific practices of holistic medicine. The emphasis on taking responsibility for the direction of one’s own treatment, for example, is certainly wise. No matter how concerned and compassionate a doctor might be (and not all of them excel at this part of their job), they cannot be as concerned as the patients themselves. Thus, it is very much in the patient’s interest to be well informed about the nature of an illness, and to take an active role in determining the course of treatment. Doctors make mistakes, sometimes very costly ones. They should be viewed, not as infallible miracle workers, but as knowledgeable consultants who assist the patient in doing battle with a particular illness.

Another positive feature of holistic medicine is its emphasis on prevention. Although both preventive medicine and direct intervention can be effective in thwarting disease, prevention is generally less aversive and less expensive. It can also be more effective. Many people are surprised to learn that relatively little of the improvement in health and longevity during the last two hundred years is due to drug and surgical treatment of sick individuals. Most of the gain is attributable to various preventive measures such as improved sewage disposal, water purification, the pasteurization of milk, and improved diets. In fact, our greater longevity is mainly due to our increased chances of surviving childhood, chances increased by these very preventive measures and by the introduction of vaccines for the infectious diseases of youth. The life expectancy of those who make it to adulthood has not changed much during the last hundred years. The life expectancy of a 45-year-old man in the nineteenth century was roughly 70 years, a figure not much different from that of today.

Another way in which the field of holistic health is often beneficial is by helping people to cope with their illness, their disability, or their pain. This is particularly important in today’s world where very few of the advances in medicine are of the “magic bullet” variety that completely cure or eradicate a given health problem. Progress in the war on cancer, for example, is slow and incremental. Prognoses are improving and patients are being kept alive longer, but often under a trying regimen of nauseating drugs and disfiguring surgery. The net effect of many of today’s medical advances is that people are able to live with their illnesses longer. Various holistic health practices such as meditation, deep muscle relaxation, and positive mental imagery can make doing so easier and more gratifying. Even if such practices did nothing at all about the underlying organic causes of illness, they nevertheless help people to manage their symptoms, and they give people a sense of control over their illness—a sense of control that might be tremendously beneficial even if it turns out to be illusory.

The Unknown Side of Holistic Medicine.
Holistic practitioners make a number of claims about how the mind can influence the body that cannot be evaluated adequately at the present time. Sober scientists claim that a person’s moods and personality can influence the functioning of the immune system. Pop enthusiasts assert that spiritual harmony and moral integrity have similar effects. Holists from both groups argue that mental imagery might prevent or arrest organic disease.

These claims touch on one of the most exciting areas of research in all of science, the field of psychoimmunology. Researchers in this area are concerned with mapping out the biochemical pathways that connect the brain and the immune system, and thus with how mental states might influence a person’s health. Although a number of exciting discoveries have been made, the field is not sufficiently advanced to permit a definitive critique of various claims like those mentioned above. (Incidentally, the very existence of this active field of research within “mainstream” biomedicine contradicts a claim often made by holistic health advocates—that research on the interaction between the mind and body is actively discouraged and even suppressed by the medical “establishment.”)

Although it may be too early for definitive answers to many of these questions, a few tentative assessments and predictions might still be warranted. My own view is that the most extreme hopes and predictions about this area of research ultimately will prove to be unfounded. For instance, I am skeptical that mental imagery, however beneficial it might be psychologically, will ever constitute an effective technique for arresting or eliminating organic disease. In part this skepticism stems from a simple “regressive” prediction (see Chapter 2): Very few of the most extreme predictions of
any
emerging field turn out to be true. The “smart money” generally lies on the more modest claims.

Beyond such abstract considerations, however, there are various features of the research findings themselves that warrant some caution about the scope of eventual practical application. One source of potential skepticism, one that is sure to sound paradoxical to some people, is the very abundance of findings that have already been reported in the literature. Sometimes it seems that virtually any psychological variable that might influence the immune system has in fact been shown to have an effect. There are studies indicating that taking an examination, suppressing anger, wanting to exercise power over others, or feeling socially isolated all serve to inhibit certain indices of immune function; whereas relaxation, mental imagery, and watching a comedy film all serve to enhance them.
²²

Together, these findings make it abundantly clear that mental states can exert some influence over the immune system. This by itself is not surprising because it has been known for years that stress can lead to illness. But when we add together all of these more recent findings, they seem to imply the existence of a world very different from the one we inhabit. They suggest a world in which it is mainly the unhappy, the asocial, and repressed who become ill, and one in which our mere thoughts can mitigate the ravages of disease. This jars with our experience of a world in which illness strikes blindly and progresses inexorably in the face of the individual’s conscious efforts and desires to stay healthy.

How can we reconcile this optimistic body of research with the grim face of everyday life? One solution is to suggest that although it is relatively easy to demonstrate effects of mental states on certain aspects of immune function, the resulting changes in the immune system may have less of an effect on a person’s health than one might initially suspect. Indeed, a number of immunologists have questioned whether specific changes in immune function such as those described above have any effect on an individual’s susceptibility to illness. There is no single, valid measure of immunocompetence, only a host of indices related in complex ways to a person’s overall ability to resist disease. Thus, temporary deficiencies in specific immune functions may not be terribly significant because they are generally followed by quick recovery and can be compensated for by changes in alternative areas of the immune system.
²³
Other investigators argue that while mental states might exert some influence on the initiation of disease, they are likely to be powerless to affect advanced organic pathology.
²⁴

It may be helpful to examine this issue from a historical perspective. Until very recently, it was widely believed that the immune system operated independently of the central nervous system and thus functioned completely beyond our control. Such a belief was not only consistent with existing knowledge of physiology, but it also made sense from the standpoint of adaptive evolutionary design. Biological functions as important to survival as the immune system might work best if they operate autonomously and are not subject to the vicissitudes of conscious thought. Just as we want our muscular reflexes to be automatic and encapsulated from mental states, we might want our immune system to be equally impenetrable. Because sadness, anxiety, and anger are such common emotions, individuals whose immune functions are dampened by such states are at risk. An advantage in the evolutionary battle for survival would seem to belong to those whose immune functions remain unaffected.
*

Advances in our knowledge of physiology have dispelled the idea that the nervous system and the immune system are completely independent. Nerve fibers have been detected in the thymus, spleen, lymph nodes, and bone marrow (regions that produce our most important immune cells), and chemical receptors for various neurotransmitters have been found on immune cells themselves. This does not mean, however, that the argument of adaptive design no longer has any force. We may still be better off with an immune system that is at least semi-autonomous. An immune system that is easily influenced by various mental states might provide certain benefits such as the ability to lessen the symptoms of disease by mental imagery. But there would also be severe costs to such a system. It is at least as easy to imagine bad things happening as it is to imagine good; it is at least as easy to picture disease as it is to picture health. Thus, if our health were as susceptible to the products of our imaginations as some of the pop advocates of mental imagery would have us believe, it is not clear that it would be much of a blessing. Indeed, if such were the case, it is not clear how medical students would survive (literally) their first year of medical school: Upon learning about a new disease, many students imagine (
vividly
) either that they have it or that they might get it. Perhaps they are better off with an immune system that ignores their conscious thoughts.

Indeed, the idea of an immune system that is so responsive to the products of one’s mental and emotional life has its troubling aspects. It may be preferable to have a system that hums along just as efficiently regardless of one’s mood. It may be preferable to have a system that does not put one at risk after seeing a sad film, delivering a speech in front of a critical audience, or learning that one’s dog has died. Personally, I find it more comforting to believe that whatever crosses my mind will
not
affect my health. Indeed, if you are like me, then the very thought that the products of our imaginations might influence our state of health produces a flood of images of hair loss, cardiac arrhythmia, and advanced carcinomas that, according to many holists, should have dire consequences. The phenomenon is analogous to the results of a simple thought experiment: When asked to imagine that someone can “read your thoughts” or listen in on your internal dialogue, many people report that they cannot avoid thinking of their most humiliating impulses. Similarly, if it were ever conclusively demonstrated that our health conforms to the pictures we have in our minds, I suspect that most of us would have difficulty suppressing images of pathology and decrepitude.