HOW EMOTIONS MAY CONTRIBUTE TO CANCER
The traditional Chinese medical view of cancer etiology holds that there are several possible contributing factors, and that one of the principal causes is internal factors, namely emotions (see: Oriental perspectives on cancer and its treatment, and Emotions and health). For example, Sun Binyan writes in his book Cancer Treatment and Prevention (1):
According to our understanding of the tumor patient, most have suppression of the emotions. They tend to hold in their anger. Although some patients have good results after treatment, emotional stimulation may cause them to decline again and then the previous treatment would have been in vain. Some people have a severe phobia about cancer. Before they know the real disease, they have a lot of suspicion. Once they know they have the cancer, their whole spirit breaks down. This kind of spiritual state is very bad for the treatment.
In the book Prevention and Treatment of Carcinoma in Traditional Chinese Medicine (2) Jia Kun gives 10 recommendations for prevention. In addition to good environment and personal hygiene, proper levels of work (exercise) and rest, good eating habits and proper food, avoiding smoking, and timely treatment of all ailments, he states that:
Emotional changes, such as worry, fear, hesitation, anger, irritation, and nervousness should be prevented. Mental exhaustion is harmful and life should be enriched with entertainment.
Shi Lanling and Shi Peiquan mention the etiology of various cancers in their book about Experience in Treating Carcinomas with Traditional Chinese Medicine (3), as regards the effect of emotions:
The etiologic factors of the disease involve chiefly the disturbance of the seven emotions, especially melancholy, anxiety, and anger, which are liable to impair the spleen and the liver. Impaired by melancholy and anxiety, qi will be stagnated and the spleen will lose the function of transformation and transportation, leading to disturbance of water metabolism and the subsequent accumulation of phlegm-dampness, while, impaired by anger, the liver qi will be stagnated. The stagnated liver qi, as qi is the commander of blood, may give rise to blood stasis if not relieved in time. Thus, emotional disturbance, in-coordination between the ascending-descending movement of qi of the zangfu organs, sluggish flow of qi and blood, and the ensuing obstruction of dampness, phlegm, and blood stasis are the fundamental pathogenesis of the disease.
The authors go on to mention other contributors, such as consumption of food that is "rough, hot, or hard," indulgence in smoking, alcoholism, traumatic injuries, and chronic ulceration. In their section on treatment of breast cancer, the authors refer to a discussion in a Ming Dynasty text by the surgeon Chen Shigong (1555-1636 A.D.) indicating that breast cancer "results from anxiety, emotional depression, and overthinking which impairs the liver, spleen, and heart and causes the obstruction of the channels." This text is also mentioned in The Treatment of Cancer by Integrated Chinese-Western Medicine (4), translated this way:
Breast cancer is due to worry and melancholy. Lots of ideas hanging around make one feel dissatisfied. Perverse flow of liver qi to the spleen leads to the obstruction of the channels and collaterals and congealations due to excessive accumulation.
Pan Mingji, in his book Cancer Treatment with Fu Zheng Pei Ben Principle (5), presents a section on etiology of cancer, listing 5 contributing factors. The first item mentioned is emotional disturbance:
TCM embodies changes of spirit and sentiment as the seven emotions: pleasure, anger, grief, fear, yearning, sorrow, surprise, all of which are emotional, physiological reactions of an organism towards external changes in its environment. Emotional disturbance refers to reactions, either excessive (excitation) or insufficient (inhibition) which will ultimately lead to disturbances in the flowing of qi and blood and the visceral functions, with subsequent illness. TCM claims rage harms the liver, excessive stimulation harms the heart, grief harms the spleen, great sorrow harms the lungs, and fear harms the kidneys. Though not necessarily precise, this belief definitely points out that emotional injury will effect the physiological functions of the qi, blood, viscera, and channels, and lower the body resistance, resulting in disease. The human body is susceptible to cancer when under emotional stress or disturbance. This is mentioned early in Chinese medical classics, such as Yellow Emperor's Canon of Internal Medicine and Golden Mirror of Original Medicine.
This Oriental view that emotions contribute to cancer formation differs from that adopted by Western scientists, who regard cancer as a change in DNA that is induced by a chemical agent, radiation exposure, or insertion of viral genes (in a few cases, the abnormal DNA may already be present in the genetic heritage of the individual; this situation usually leads to cancer at earlier age). In order for the induced DNA change to lead to cancer, it is first not properly repaired by certain DNA repair proteins and then the abnormal cell is not destroyed by a natural cell death process (apoptosis). Cancer initiating factors act within the environment of the individual-which includes the person's genetic background and nutritional status-to trigger the development of cancer. Thus, lung cancer is often caused by breathing carcinogens such as those contained in cigarette smoke; stomach and colon cancer are often caused by carcinogens in the food supply; skin cancer may be induced by excessive exposure to the ultraviolet light of the sun; and leukemia may be induced by exposure to industrial chemicals, to radiation, or to a virus that resides in the bone marrow. Traditional Chinese doctors were aware of this type of etiology. For example, they recognized that cancer occurred more often in certain places and was attributed to something in the drinking water, or that cancer could be induced by rotted food and, in modern times, by smoking. Yet, it was the emotions that were often regarded as the most significant factor. At the least, the excessive and/or suppressed emotions would cause disruption of the internal organs and flow of qi and blood, and then the external factors would more easily induce further damage.
Western researchers have not undertaken detailed study of the possibility that persistent or repeated experience or suppression of emotions contributes to the risk of cancer for several reasons. Aside from a low motivation to undertake the study because other factors are considered more important, such research is extremely difficult to perform properly. One would have to recruit a very large number of people into the study, have some reliable method of measuring emotional status over a long period of time, and then find some way to quantitate the emotional condition (as it varied over time) so as to compare with the actual incidence of cancer among individuals under study. Still, the fledgling field of psychoneuroimmunology (the study of how psychological states, as detected in activity of the nervous system, impact the immune system), has developed some evaluations that suggest emotional stress increases a person's susceptibility to cancer (12).
The emotional status of patients after receiving a diagnosis of cancer has been studied extensively, though even that has proven difficult. In one recent study in Denmark (6), women who had just been diagnosed with breast cancer that was considered to have a low risk of recurrence (easily treated, not metastasized) were compared with women from the general population. A frequently relied-upon study questionnaire (hospital anxiety and depression scale: HADS) was used to determine the level of anxiety and depression in these two groups. To their surprise and consternation, the authors found that the women diagnosed with breast cancer, albeit a low risk breast cancer, had an average anxiety and depression level lower than that of the general population. They suggested that the HADS questionnaire might not be suitable for questioning the general population (as it had been developed for studying people hospitalized with various ailments). One might expect that if women with breast cancer tended to have a life-long history of depression and anxiety that helped lead to formation of the tumor, or if these emotional conditions were recent and had some role in inducing the cancer, then this group would have a higher than typical level of depression and anxiety compared to the general population, even if receiving the diagnosis of breast cancer did not worsen their mental condition. The results may simply reveal the difficulty of designing and carrying out a meaningful study, since other studies have found that anxiety and depression in cancer patients tends to be a significant problem.
In China, one published study (7) involving a huge population (750,000 people in Beijing) attempted to find out if psycho-social factors contributed to the incidence of primary lung cancer. They reported that their study showed three factors positively associated with occurrence of lung cancer:
Poor relationship with coworkers would generally suggest that there is emotional tension during the work day, so all of these could indicate emotional disorders associated with higher incidence of cancer. When "depressive feeling for a long time" was analyzed further, it was found that this was a significantly stronger risk factor for women than men. This study supports the traditional Chinese contention that emotions can contribute to cancer incidence, but it would need to be verified by a tightly controlled trial in order to convince Western researchers that the results could have important implications for understanding the etiology of cancer.
If the contention that emotions contribute to cancer formation is to gain acceptance outside the field of traditional Chinese medical practitioners, finding a biological mechanism of action that could be measured in the short-term would be an important contribution. For example, if during a period of emotional stress there occurs a biochemical or physiological change that is understood to contribute to oncogenesis (cancer formation), then one could reasonably contend that emotions may be causing or working with other factors to cause some cases of cancer.
One of the biological mysteries that has faced researchers in recent years is the relationship of estrogen to breast cancer (see: Estrogen dependent tumors and herbs). For years, concerns have been raised about giving estrogen in hormone replacement therapy to women who were considered at risk for breast cancer due to familial history (genetic background). In fact, the familial history of breast cancer is a contraindication to using hormone replacement therapy after menopause. Based on a variety of research findings, it appeared as if estrogen, whether produced by the body or given as a pill, might cause the cancer, which seems peculiar, in that it is a normal component of the body.
Recent findings shed light on how estrogen is involved in oncogenesis and provides a model for a possible role of emotions (this model is highly speculative at this time, and is only used as an illustration). Estrogen is converted into different metabolites prior to elimination. There are two major metabolites-products of enzymes acting on estrogen-one of which can get to the DNA and actually induce cancer, and another which may help prevent cancer (8). One might say that there are "good" and "bad" estrogen metabolites. It is a situation that is reminiscent of the "good" and "bad" cholesterol in relation to heart disease. With cholesterol, it is actually the carrier molecules that are different: high density lipoproteins (HDL) and low density lipoproteins (LDL). HDL helps to prevent heart disease, while LDL contributes to it, because they have differing roles in transport and deposition of the cholesterol.
Researchers have found that exercise, which is a normal healthy activity, increases the HDL and decreases the LDL, thereby reducing the risk of heart disease. What if emotions, perhaps certain types of emotions (anxiety, depression) stimulate the enzymes directing more of the estrogen to the "bad" type of metabolite, rather than the "good" one? This would result in increased cancer risk; the risk would be substantially increased if the estrogen levels were unusually high (as when giving hormone replacement therapy), since there would be much more estrogen to be converted to the carcinogenic form.
Differences in metabolism of substances have been proposed as a basis for why some individuals develop cancer. In the book How to Discover Cancer Through Self-Examination (9), an example is given:
Polycyclic aromatic hydrocarbon is a very strong chemical carcinogen; but when it enters the human body, it will only cause cancer when functioning in the cell through the transformation of polycyclic aromatic kinase. If the content of kinase in the human body is high, it is easy to engender cancer when in contact with the chemical substance; to the contrary, the probability of cancer incidence is lower if the content of kinase is low, even if the person contacts the chemical.
Potential contributors to the level of enzymes (both those that transform chemicals into carcinogens and those that transform carcinogens into non-carcinogens) include genetic background, stimulation of the enzymes by other chemicals (e.g., alcohol and some other substances stimulate the liver to produce a large group of enzymes in substantial amount), nutritional status (some enzymes are affected by trace elements and vitamins that act as coenzymes), tissue injury (liver damage may affect enzyme production), and other factors. It is possible that stress hormones released in response to emotional changes can affect the levels of enzymes.
Certainly, the levels of the estrogens themselves vary markedly among individuals. In a study of estriol, estrone, and estradiol at days 10-14 of the menstrual cycle in women with regular menstrual cycles, it was found that estradiol levels were as low as 11-31 pg/ml (picograms per milliliter) in women with low levels but as high as 157-189 pg/ml in those with high levels (16). Since estradiol is currently considered a major hormonal contributor to breast cancer risk, this marked variation shows that the factors (as yet unidentified) that influence the hormone levels can have a substantial impact.
At this time, there is no direct evidence that emotions cause such a shift in estrogen metabolism that might lead to higher risk of cancers, such as breast cancer. But, there is no question that emotions can impact the physiological functions, and this model is just one example of how they might translate into a higher cancer risk that could be detected by a properly designed study.
The Chinese physicians who comment about the role of emotions in cancer formation point to the fact that the internal viscera become weakened, thus increasing the opportunity for pathologies of all types, including cancer. Western research has already supported the idea that depression can impair immune system functions (perhaps indirectly, such as by repeatedly impairing a good night of sleep, with sleep contributing to maintenance of the immune system). It has been shown that tumor-relevant lymphocyte subpopulations, such as natural killer cells (NK cells; these can directly attack cancer cells), have receptors for various neuropeptides, including those released during stress. This finding indicates how NK cell activity could be modulated by a person's emotional responses. The level of NK cell activity has been found to be a reasonably good predictor of breast cancer outcome; further, a portion of the loss of this activity in cancer patients was shown to be correlated with psycho-social measures such as patient "adjustment" (avoiding showing distress at the cancer diagnosis/treatment), lack of social support, and symptoms of fatigue/depression (14).
Along these lines, the immune system may regulate the activities of enzymes, such as aromatase, that converts estrogens to estradiol in breast tissue (17, 18). Cytokine changes (as occur with infection and inflammation) have been observed in cases of major depression, and have been suggested to be a potential cause of depression (19, 20). In fact, some antidepressant drugs are tumor necrosis factor (TNF) inhibitors; this being one of the cytokines that causes considerable adverse effects in cancer patients and those with life-threatening infections, such as HIV. It is also possible that depression, and other emotional disorders, will affect the cytokines.
In the book Why We Get Sick (10), which is based on the premise that most of our body (and mental) functions have been determined by evolutionary factors, the author explains how a potentially helpful feeling (anxiety) can have harmful physiological effects:
Everyone must realize that anxiety can be useful. We know what happens to the berry picker who does not flee a grizzly bear, the fisherman who sails off alone into a winter storm, or the student who does not shift into high gear as a term-paper deadline approaches. In the face of threat, anxiety alters our thinking, behavior, and physiology in advantageous ways....Because anxiety can be useful, it might seem optimal to adjust the mechanism so that we are always anxious. This would be distressing, but natural selection cares only about our fitness, not our comfort. The reason we are sometimes calm is not because discomfort is maladaptive, but because anxiety uses extra calories, makes us less fit for many everyday activities, and damages tissues. Why does stress damage tissues? Imagine a host of bodily responses that offer protection against danger. Those that are "inexpensive" and safe can be expressed continually, but those that are "expensive" or dangerous cannot. Instead, they are bundled into an emergency kit that is opened only when the benefits of using the tools are likely to exceed the costs. Some components are kept sealed in the emergency kit precisely because they cause bodily damage. Thus, the damage associated with chronic stress should be no cause for surprise....In fact, recent work has suggested that the "stress hormone" cortisol may not defend against outside dangers at all, but instead may mainly protect the body from the effects of other parts of the stress response.
Just as Chinese therapeutic dogma holds that one can use a powerful remedy that may weaken the individual temporarily in order to gain an advantage over a disease, the body also can sacrifice some of its well-being, temporarily, to save itself. However, if the "emergency kit" is left open for an extended period of time, by living in a situation that the body and mind deems unsafe, then progressive damage to the tissues can occur. This damage may then cause or exacerbate chronic disease or a life-threatening event (e.g., stroke, heart attack, incurable cancer).
Indeed, it is possible that even a single period of intense stress lasting months, such as occurs with a divorce, death of a family member, loss of job, or other life-changing event, rather than decades of habitual emotional distress, might lead to serious damage to the tissues which could trigger the development of cancer. The stress hormones might themselves stimulate latent cancer cells into reproduction; the hormones or their metabolites might transform a normal cell to a cancer cell; or the damage to the tissues may lead to failure of normal cancer-control mechanisms. In this way, a diagnosis of cancer may be encountered a year or two after such an event (it takes that long for the cancer to develop enough to yield evident symptoms or a diagnosable lump). Such a correlation-between stressful events and subsequent cancer diagnosis (13) or recurrence of previously treated breast cancer (15)-has been supported by early studies that still require replication. If severe emotional stress (of the type that is likely to be mentioned during questioning) does sometimes give rise to cancer soon after the stress is experienced, this would certainly explain the observation made by traditional practitioners: that emotions are a cause of cancer.
APPENDIX 1: Concerns About Attributing Cancer Causation to Emotions
Some readers may raise the objection that attributing cancer causation to emotions could place an extra burden on the cancer patient: namely blaming the individual for causing their condition (this point was raised by one of the clinicians at ITM). For each individual cancer patient, blaming their cancer on any particular cause is probably of no value. Whether the cancer is blamed on an environmental chemical introduced by a reckless corporation, or on a high fat diet, on smoking, or on an inherited gene, the treatment of the cancer is not significantly altered; it is not possible to go back and undue the damage. Therefore, to become involved in the matter of placing blame for any individual case is a futile effort. Indeed, no matter what is blamed, the process of placing blame may simply stimulate more emotional distress (e.g., anger and over-thinking) that impairs the healing process.
However, discovering possible contributors to cancer, whether emotions or external factors, is helpful for the general population, as it might direct individuals to take measures to minimize their risk. If, as postulated, emotions contribute to cancer formation, then activities that control the emotions (see: Emotions and health) may be among the valuable pursuits in maintaining health. It is also possible that the same practices would be of special interest to those who have been diagnosed with cancer, who were then treated successfully, but remain at risk for recurrence of cancer.
Reading the alternative medical literature makes it clear that a large part of the alternative health care movement in the U.S. has focused on the concept that many ills, including cancer, are mainly caused by persons other than the one who suffers from the disease. Therefore, blame is placed on pollutants, food additives (including pesticides) and food processing, stripping of nutrients from the edible plants by modern agriculture practices, radiation from electric power lines and cellular phones, prescription drugs, dentists applying mercury amalgam, and the deceptive statements of the tobacco industry and the food industry (to name a few of the culprits). The role of the individual in properly selecting lifestyle choices that affect health (a selection process that is much helped by learning from those who are wise) are not emphasized except when the blame can be attributed to another party that is also involved. Thus, while having children relatively early is deemed the best natural protection against breast cancer (11), the choice of having children later in life as a major factor in the increasing breast cancer rates is never mentioned by proponents of alternative medicine (as they may endorse this particular lifestyle change from past practice). Instead, birth control pills are blamed (13), perhaps because a pharmaceutical company has manufactured them and a doctor has prescribed them (two external targets of blame).
In traditional medical systems, such as Chinese medicine, serious diseases are thought to have several possible contributing factors, but personal practices are deemed especially important in preventing the diseases. Thus, in Jia Kun's outline of cancer prevention activities (2), he includes personal hygiene, proper work and rest, physical exercise, good habits, proper cooking of food, getting physical examinations regularly, and getting treatment for ailments promptly, as well as avoiding emotional disturbance. In addition, he recommends that people should consume stalactite (this is the cave mineral deposit that provides an abundance of trace minerals, though calcium is the dominant component) by putting stalactite into the water supply, making tea with it, or consuming the powder (this is a type of mineral supplementation; today, several minerals, especially calcium and selenium, are thought to have benefits for preventing and treating cancer). When it comes to industrial pollution, he says that: "Harmful gas should not be released into the atmosphere, and planting should be carried out to purify the air," but his longest dissertation is about proper selection and preparation of food.
Thus, the concern that a link between emotions and cancer formation could lead to a worsening mental state due to blaming oneself may simply be a reaction that results from the frequent practice of blaming others for our poor health, a practice that should be modified. No doubt there are several external factors introduced in modern society that contribute to ill health, but the tendency to focus on these influences may result in a particular sensitivity about considering one's personal responsibility for making daily choices that promote good health (see: Promoting health and relaxation during the four seasons). As Pan Mingji relates (9):
The external causes of cancer have been all narrated above [included in the preceding pages of his book are the following external causes: contaminated drinking water, moldy food, smoked fish and meat, food polluted by radioactive materials, cigarette smoking, alcohol abuse, chemical food colorings, eating overly hot food, poor posture during eating, work environment contaminated by chemicals], nevertheless, it is the internal cause that takes determinable effect. For example, in coming into contact with the same carcinogen, some people will develop cancer while others will not. Even in areas where cancer occurs at a high rate, only a tiny minority of people die from it while the overwhelming majority of them still live healthy and sound. This illustrates that the occurrence and development of malignant tumor relates closely to the internal factors of the organism. There are a lot of factors which affect the anticancer ability of the organism, but the leading one has to do with whether the spirit, nervous system, and various defenses of the organism are perfect. A lot of evidence proves that those who are optimistic and undertake exercises [in China, this refers mainly to taiji and qigong, along with similar types of practices] tend to have healthy and sound function of the nervous system, strong physiques, and naturally great anticancer ability and immunity. Even if those people come into contact with outside carcinogens, they will not develop cancer. On the contrary, those who have mental injury, who are disheartened, or often have a fear of cancer, and who do not undertake exercises at all or are overtired, whose daily life is irregular and unsanitary, whose spirit and nerve function is disorganized, tend to reduce their defensive ability. As a result, the rate of cancer occurrence among those people is higher.