What Is It?
Traditional Chinese Medicine (TCM) is marketed as a set of theories and practices developed over centuries in China. In reality, it is a label applied to a varied and inconsistent set of practices drawn from a variety of competing traditions, as well as many modern innovations. The term “traditional” is a misnomer for the companion animal applications of TCM in particular, since historically most TCM concepts and techniques were not applied to pets. The more abstract theories were only held to apply to humans, and the pragmatic use of herbs and other remedies were mostly reserved for agricultural and working animals.The application of theories and practices under the label of TCM to pets is quite recent. The primary methods of treatment in TCM include acupuncture, herbal remedies, a manipulative therapy called tui-na, and alterations in diet.
Though much historical Chinese folk medicine was pragmatic (applying various treatments to symptoms by trial-and-error) TCM as it is packaged today in the West includes a number of theoretical concepts that are variants of Daoist metaphysics and folk cosmology. The fundamental nature of the universe and everything in it is conceived as a condition of balance between opposing aspects of existence known as Yin and Yang. Cold and heat, dark and light, old and young, and so on are seen as examples of this balance between opposites, and all diseases are believed to arise from a disharmony or loss of balance between Yin and Yang. Infectious organisms, toxins, trauma, and other causes of illness recognized by scientific medicine are not considered as true causes in the TCM paradigm, but as manifestations of disharmony. According to Huisheng Xie, the leading figure in veterinary TCM in the United States, “no disease occurs if Yin and Yang maintain a relative balance.”
Yin and Yang are also identified with particular temperaments, organs of the body, seasons, and other features of living organisms and the environment, and this is taken to illustrate the centrality of these concepts and the balance between them to all features of the universe. This notion of balance between forces represented by the five elements (earth, air, fire, water, and wood) or bodily fluids bears a strong resemblance to the humorism of ancient Greece and Rome, India, and many other cultures. Humorism, practiced in the West until the twentieth century, identified imbalance in humors (blood/air, yellow bile/fire, black bile/earth, and phlegm/water) as the cause of all disease and associated these humors with pairs of opposites such as heat and cold, winter and summer, and so on. Practitioners of humorism attempted to maintain and restore health by restoring balance among the humors, much as TCM practitioners attempt to rebalance Yin and Yang. This was accomplished through bloodletting, herbal remedies, cauterization, and many other practices common to historical and contemporary TCM. This humorist model and the associated practices were abandoned in the West with the advent of modern scientific medicine.
The concept of Yin and Yang is applied to health through an intricate system that varies significantly between individual doctors who employ TCM. In general, practitioners evaluate the appearance of the tongue, the pulse, and a host of other characteristics of individual patients to categorize the problem in terms of excess or deficiency of Yin and Yang. Individual treatments are assigned as promoting or reducing Yin and Yang, so the remedies are chosen based on the categorization of the problem. Egg and banana, for example, are cooling foods, while garlic and ginger are warming foods. Herbs, acupuncture points, and other treatments are assigned in the same way by tradition, taste, or other criteria.
The names of organs are used in categorizing a disorder according to the TCM system, but it is important to note that this is a metaphorical use of these names, associating certain functions and Yin or Yang with certain organs, somewhat like the metaphorical use of the heart as a symbol for strong emotions (as in “He followed his heart”) and the association of bile with bitter or hostile temperament (as in “You’ve got a lot of gall!”). These names do not imply the anatomical or physiological relationships understood in scientific medicine. This makes it possible, for example, to adjust the Gall Bladder function in a species like the horse, which doesn’t actually have a gall bladder.
A couple of case examples from Dr. Xie’s text will illustrate the general thought process of TCVM.
1. Signalment: Seven year old, female spayed Labrador Retriever
Primary Complaint: Separation Anxiety
History ad Physical Findings: From a western perspective, the dog has all the signs of separation anxiety. Acupuncture treatment did not help much. She has been on the herbal formula Long Dan Xie Gan Wan for signs of Liver Stagnation.
Her tongue is slightly red and dry and her gums are tacky. Her eyes are red. Her pulses are thready and fast.
Assessment: This is a Yin Deficiency Pattern (Deficient Heat), specifically a Heart Yin Deficiency pattern. The Yin Deficiency can be determined from the red, dry tongue (Heat signs) and the thready and fast pulse. The association with the Heart is based on the major complaint of separation anxiety because this is due to a Shen (Spirit or Mind) disturbance. Of the five Yin organs, the Heart is the one that houses the Shen. Separation anxiety and other behavior problems are mostly related to the Heart. The treatment strategy is to balance Yin and Yang by enhancing Yin. The acupuncture points An Shen, HT-7, Da Feng Men, and KID-3 as well as the herbal formula Shen Calmer (Modified Tian Wan Bu Xin Dan) are recommended for this case.
2. Signalment: A thirteen year old female spayed American Eskimo dog.
a. Cushing’s disease which has been treated with Mitotane for the past four years.
b. Seizures which began last month and clustered about once a week.
d. Generalized stiffness with weak hind end. There is no limping, but the dog’s gait is very stiff. The dog takes three to four steps then huffs and puffs and lies down.
e. Generalized lethargy, weakness, lack of energy.
Physical Findings: Pulse is thin and fast; Ravenous appetite and thirst; Bilateral cataracts; Deafness; Panting Constantly; Poor teeth and gums; Rose colored thin ocular discharge; Stool dark brown and foul smelling; Chronic urinary incontinence, all day, all the time; Draining pressure sore on left hip; Pot-bellied with muscle wasting; Tongue is pink with thin coating
Assessment: This can be considered a Deficient Heat (Yin Deficiency) condition, with a Qi Deficiency and Internal Wind. The old age, weakness, urinary incontinence and lethargy indicate a Qi Deficiency. The fast pulse, thirst, ravenous appetite, constant panting and foul smelling stool can indicate Heat. Seizures are caused by Internal Wind.
The treatment strategy is to use acupuncture to balance Yin and Yang by enhancing Yin and clearing the Wind. In addition, acupuncture can be used for the stiffnedd while using Chinese Herbal medicine for the internal organ problems. Acupuncture points such as GB-20, LIV-3 and GV-20 may be beneficial for the seizures (Wind). The points KID-3 and SP-6 may be beneficial for Yin. Two herbal formulas may be beneficial: Tian Ma Gou Teng Yin for Internal Wind and Suo Quan Wan for incontinence and Kidney Qi Deficiency.
Clearly, TCM has an intricate theory and methodology. One can undertake years of training and study in this system, and it is possible to obtain advanced degrees, even PhDs in the subject. This can create the impression that the system must be rational or else why would it be so complex and so academic. As I’ve discussed many times before, however, the strength of adherents’ faith in and idea, the number of adherents, or the length of time the idea has been around are not reliable indicators of whether the idea is true. The theories and practices of humorism dominated Western medicine from the time of Ancient Greece into the twentieth century, yet they were mistaken and ineffective. And the appearance of scientific or academic legitimacy conveyed by Tooth Fairy Science and Quackademic Medicine is equally unreliable. Any idea, regardless of its source, must stand or fall on the merits of reliable, objective evidence. And in reality, TCM does not have the lengthy pedigree as a unified and coherent system its proponents claim anyway. And as I’ve discussed in previous articles, it isn’t even all that popular in China.
Does It Work?
So is there such evidence to support the theories and practices of TCM? Well, the theoretical foundations claimed as the basis for TCM involve undetectable energies and spiritual forces, so they amount to a religious belief system more than a model of the functioning of living organisms. This, of course, cannot be tested by any scientific means and so must either be believed on the basis of faith and personal intuition or experience or rejected on the same basis.
These theories have no consistent relationship to the scientific understandings of anatomy, physiology, or other factors in health and disease. Contrary to popular misconceptions, TCM diagnoses and treatment guidelines are not simply a different set of metaphors for describing the same things scientific medicine talks about. Acupuncture points, for example, do not consistently correspond to detectable anatomical features. And as already pointed out, the use of organ names in TCM is purely metaphorical. So the TCM system of understanding health and disease is entirely separate from the scientific system and cannot be integrated with it, whether or not scientific and TCM treatments are used together.
Much of TCM theory and practice cannot be tested scientifically, but some interventions can. Of course, this raises the theoretical issue of whether or not they should be. Since the way medical problems are categorized and interventions are assigned is based on a metaphysical ideology not compatible with scientific explanations of the world, there is no underlying biologic plausibility to these processes. The only reason to consider investigating them seriously is the belief of those who practice and receive them and, which is a deeply unreliable indicator of the validity of ideas generally. Still, on a pragmatic level any method that is sufficiently popular is likely to draw additional adherents on the basis of testimonials alone, particularly with the added allure of Orientalism TCM has. Therefore it is worthwhile to examine at least some of the claims made for such an approach in an objective scientific way and see if there are any indications of real effects despite the lack of a plausible theoretical foundation and the largely manufactured history claimed for TCM.
Because the TCM system is complex and involves multiple modes of treatment, each of these specific practices must be tested independently. It makes no more sense to ask “Does TCM work?” than it does to ask “Do drugs work?” Penicillin works for certain kinds of bacterial infections, but not for cancer, depression, or a broken toe. Similarly, acupuncture may have detectable effects for some conditions and not for others. Scientific medical research is not about validating or invalidating an entire philosophy or world view, but about identifying the effects of specific interventions on specific problems under specific conditions. If the argument is made that TCM fundamentally cannot be examined in this way, then it must be considered a belief system or faith healing practice, not a branch of medicine, and it should be practiced or dismissed on the basis of personal faith like any other religion. If, however, TCM is to be taken seriously as a medical approach, it must be pass or fail the same tests of legitimacy as any other healthcare approach.
I will look at each of the major branches of TCM treatment separately to discuss the scientific evidence concerning their effects.
This is probably the most thoroughly studied and understood of the TCM interventions, and I have written about it extensively. In brief, the evidence in humans shows some mild beneficial effects for subjective symptoms such as pain, nausea, depression, and so on. These effects appear to be largely psychological as they can be elicited by needling practices that are “incorrect” according to any of the various semi-official lists of points and methods (or even by non-penetrating needles or poking patients with toothpicks), and they follow the usual patterns of placebo effects (stronger if presented confidently rather than hesitantly, not consistently detectable through blinded, objective measurement variables, etc). It does not appear that the actual physical manifestations or overall course of any disease is significantly altered by acupuncture, but the psychological benefits of the treatment ritual may be sufficiently beneficial for some patients to be worthwhile.
There is little research on the clinical benefits of acupuncture in companion animals, and no replicated, high-quality studies. There is as yet no reason to believe the results of such research would be different from those seen in humans, but the case has not yet been conclusively made. In any case, the confident claims of benefit almost universally made by practitioners of acupuncture are certainly not justified by scientific evidence.
For more information, see my previous posts concerning acupuncture, the Science-Based Medicine acupuncture section, and the excellent summaries in Snake Oil Science by R. Barker Bausell and Trick or Treatment: The undeniable Facts about Alternative Medicine by Edzard Ernst and Simon Singh.
2. Herbal Remedies:
Like herbal medicine in general, this is a complex area in which there is as yet little reliable data. Herbal remedies undoubtedly contain pharmacologically active compounds, so there is reason to believe they could have clinical effects. TCM remedies in particular are often mixtures of multiple plant and animal products, as well as contaminates and often conventional pharmaceuticals, so the pharmacology of these mixtures is complex. Since particular remedies have been assigned by tradition and personal experience to influence Yin and Yang, and since the TCM theories by which they are selected have no relationship to the causes of disease as understood by scientific medicine, there is no scientifically plausible reason to believe these remedies, whatever chemicals they contain, should be safe or effective for particular medical conditions. We have, as usual, only anecdote and tradition to support the use of these products.
A recent article provides an example specific to TCM. Certain fungi that parasitize insects have been used in TCM practice, as part of the remedy Dong Chong Xia Cao, believed to tonify Yang and promote youth and vitality. Like most ethnobotany traditions, this fungus was used for a great variety of unrelated conditions. It turns out to contain a compound which suppresses inflammation and immune function (despite the inevitable claims that the remedy “enhances” the immune system) and has a variety of other effects in vitro and in lab animals experiments. These functions make this compound potentially useful in the treatment of autoimmune diseases such as multiple sclerosis, once extracted from the original fungus and purified. However, the original substance has unacceptable toxic side effects, so it had to be modified to make it a safe and useful medicine.
This example illustrates quite nicely how the process of identifying and making use of potentially medicinal compounds in plants and other natural sources differs from the haphazard traditional use of herbal products. Advocates of herbal medicine are correct when they claim that many medicines come from plants. What they ignore or fail to mention is that these medicines are almost always safer and more effective once they have been isolated from the chemical soup of whole plant products, tested according to a thorough understanding of the relevant physiology and disease mechanisms, and often modified to be safer and more effective than the original compounds. And these plant-derived medicines frequently turn out to be useful in ways that bear little to no relationship to the traditional uses of the plants themselves.
There have been many studies of Chinese herbal preparations, including in vitro, lab animal studies, and clinical trials. Many of these are problematic in that they are small, of poor methodological quality, and often published in alternative medicine journals and Chinese medical journals, which very rarely publish any negative studies, suggesting a severe publication bias. And from a theoretical point of view, studies of individual Chinese herbal remedies for medical conditions defined in standard scientific terms make little sense. From a scientific point of view, there is no reason to think that plant products selected on the basis of undetectable energies and other mystical concepts should be effective. And from the point of view of TCM, using individual remedies utilized to treat disease as defined by conventional science makes no sense because the appropriate treatment should be comprehensive and individualized diagnosis and management of the patient according to the TCM system.
Nevertheless, some attempts to study these herbal preparations in this hybrid way have been made. Though positive results are occasionally reported, there is no repeatable, high-quality evidence to support the use of any particular remedy for any specific condition, and overall the evidence is sparse, of poor quality, and not encouraging.
Given that there are thousands of plant and animal products that have been used in TCM for innumerable purposes, it would be astounding if a few did not turn out to have some positive effects consistent with their traditional use. It is far more likely, given the existing data and the experience with investigations of other herbal medicine traditions, that most traditional uses will not be validated and that the beneficial compounds in the original materials will only prove beneficial once isolated, purified, modified, and tested according to conventional scientific practices, as with the example of Dong Chong Xia Cao already discussed.
A number of Cochrane Reviews of Chinese Herbal Medicines are available, and they generally report the quality and quantity of the evidence for most indications to be insufficient to justify a recommendation. A systematic review of all individualized herbal medicine studies, including those utilizing TCM, found, “There is a sparsity[sic] of evidence regarding the effectiveness of individualised[sic] herbal medicine and no convincing evidence to support the use of individualised[sic] herbal medicine in any indication.” More research seems appropriate, but not based solely on traditional uses of combination products selected on the basis of metaphysical criteria. As with any pharmacologically active preparation, thee herbs should be studied by first identifying potential active compounds, examining their chemical and biological properties in pre-clinical laboratory testing, verifying their safety, and only then proceeding with clinical trials for those that seem promising.
3. Tui Na:
Tui-Na is a manipulative therapy with features resembling massage and also chiropractic, though it is guided by the same theoretical and traditional principles as acupuncture. It is usually offered in conjunction with acupuncture and the other interventions associated with TCM, and there is a great scarcity of scientific research on its purported effects. It is usually included in global TCM treatment, so few studies exist examining it independent of acupuncture, herbs, and other TCM interventions. One example, looking at tui na for degenerative spinal disease in the neck (cervical spondylosis) found no good evidence of benefit.
It is tempting to lump this therapy in with massage, which like acupuncture has benefits for pain, anxiety, and other symptoms with a significant psychological component but which has not been demonstrated to meaningfully affect the outcome of any specific disease process. However, I have not found any detailed comparisons of different manual therapies and their relative effects, so this would just be speculation.
Is It Safe?
As with efficacy, the safety of TCM has to be evaluated in terms of the individual interventions employed. Acupuncture has known risks, including infections, trauma to nerves and muscles, and even death from inadvertent penetration of the chest with needles, which allows air to enter and collapses the lungs. Recently, the former president of South Korea was seen by doctors for a cough and ended up needing to have an acupuncture needle surgically removed from one of his lungs. A recent review suggests that these risks are small, and can be minimized with proper training and regulation of acupuncturists, but they are not non-existent, and in the face of questionable evidence for real benefits, even small risks seem hard to justify.
The risks of herbal remedies are likely much greater, though they are hard to evaluate in the absence of meaningful government regulation and monitoring. Herbal remedies contain active chemical compounds, and these can have direct toxic effects and they can interfere with other medications. TCM remedies have been repeatedly found to be contaminated with toxic metals, such as lead and mercury, and even conventional pharmaceuticals.
Chinese herbal remedies containing a plant called Aristolochia have been known to cause kidney failure. Deaths have been caused by the remedy ma huang due to the chemical stimulants it contains, and this product has been banned by the Food and Drug Administration (FDA). And herbal remedies have been found to be contaminated with lead and other toxins as well as pharmaceuticals. A list of references below is given illustrating the considerable risks associated with untested and unregulated herbal preparations in general, including TCM remedies, can be found here.
I am not aware of any reports of harm from tui na therapy.
The theoretical concepted promoted as the rationale for Traditional Chinese Medicine are essentially religious in their origins. They do not correlate with recognized physical phenomena understood by science, and they apparently cannot be evaluated by scientific means. The specific interventions employed in TCM, acupuncture, herbal remedies, tui na, and dietary manipulation, have not been extensively evaluated through high-quality controlled clinical testing. By far the most research has been conducted on acupuncture, which appears to have placebo benefits for subjective symptoms regardless of whether it is applied according to TCM principles or not. Most herbal remedies in TCM have not been scientifically evaluated. A few have shown promise for some conditions, but a few have also proven deadly, and potentially dangerous contamination with toxins and undisclosed pharmaceuticals is apparently common. There is no reliable evidence base concerning the safety or efficacy of TCM for pets. The few studies available do not show a consistent pattern of significant benefits.