Traditional Concepts
Traditional Chinese Medicine is, fortunately, not based on science. It is based on a paradigm of balance in nature, a concept that has existed for millennia, originating in Taoism. The heart of the paradigm is the belief that there exists in nature and in the human body, energy, referred to as Qi (pronounced ‘chee’). In order to be healthy one must have sufficient Qi, it must be balanced and it must be free-flowing within the body in a pattern that is specific to the Qi related to each of several identified organs. Blood and body fluids ground and nourish Qi to create balance so Qi can move freely in the meridians.
Traditionally, acupuncture’s effects are explained by how it influences Qi. Qi is believed to flow through ‘meridians’ or ‘channels’ along with blood and body fluids. These meridians make up a conceptual network of pathways through the entire body. The word ‘meridian’ comes from the French translation of the Chinese term jing-luo, which means “to go through” and “something that connects or attaches”. According to TCM theory, Qi forms at conception and is maintained throughout life by the intake of food, water and air. Everything in nature is classified as being either yin (cold, female, dark, inside, etc) or yang (hot, male, light, outside. etc). Under healthy circumstances, the body maintains a state of balance (i.e. between yin and yang) when Qi is moving smoothly through the meridians.
If there is an imbalance in yin and yang or if the movement of Qi is deficient, obstructed, moving in the wrong direction, or in excess, the body may be in a diseased state or more susceptible to illness. In traditional approaches, acupuncture is used to stimulate points either along meridians or points that lie outside these pathways that may connect two meridians, to correct the imbalance. A traditional acupuncturist will diagnose and treat the ‘root’ and ‘branches’ or the underlying imbalance and symptoms of the disease or disorder. In this way, traditional acupuncture treats not only the symptoms, but addresses the root cause of the underlying problem and may also prevent further illness. For more detailed information on traditional acupuncture from a traditional Chinese Medicine perspective, please see the Traditional Chinese Medicine therapy review on CAMline. http://www.camline.ca/
The reason for stating at the outset that it is fortunate that TCM is not based on science is to acknowledge its value in solving health-related problems that confound modern medicine. Often modern medical knowledge with its emphasis on studying the minute details about a condition misses the big picture one sees when symptoms are viewed through the eyes of an individual with training in TCM concepts. Using that knowledge often leads to a successful outcome for an ill person that was impossible with western medicine.
Scientific Explanations
While the concept of Qi and meridians do not correlate directly with western science (i.e. meridians and Qi are conceptual explanations and are not directly related to either the cardiovascular or neurological systems), there is a correlation between acupuncture points and known neural structures. Several Canadian researchers played instrumental roles in describing and quantifying this fact.
Dr. Chan Gunn identified 70 acupuncture points in 1976 by locating them using an ohm-meter which measures skin resistance and classified them according to their relationship to known neural structures such as superficial nerves to the skin, nerve plexi (main junctions of nerves), points where segmental nerves coming off the spinal cord meet in the midline of the body, at the joining of muscles and tendons and at ‘motor points’.5 Motor points are not physical, anatomical structures; they are points on the skin where the lowest amount of current will cause a muscle to twitch.
It is possible to locate acupuncture points using an instrument like an ohm-meter, which measures skin resistance, because there is lower resistance to the passage of electricity at acupuncture points than in the surrounding skin. This has been shown in many studies. Perhaps the most interesting anecdote to illustrate this is found in a scholarly text co-authored in 1980 by Joseph Needham with Lu Gwei-Djen, Associate Director of the East Asian history of science library at Cambridge University. Needham witnessed Dr. Raymond Evans at the Toronto General Hospital locating acupuncture points using a Japanese Ryodoraku machine and was told by Dr. Evans that the effect is demonstrable on cadavers for up to five hours after death.6
Professor Ronald Melzack of McGill University published a paper in 1977 claiming that there is a 71% correlation between muscle trigger points (TrPs) and ‘acupuncture points for pain’.7 Trigger points are tender points in tissue that, when sensitive or ‘active’, cause pain in a pattern that is particular to each TrP.8 Tissues that can harbour TrPs include muscle, ligament, fascia, periosteum and skin. It is well known that needling of tender points with acupuncture needles can relieve pain at a distance. The Chinese refer to tender points as ‘Ah Shi’ points.
Studies using functional Magnetic Resonance Imaging (fMRI) have shown brain activity in the areas of the brain that control sight and sound in response to the insertion of acupuncture needles into points on the leg that have traditionally been associated with the eye and the ear. 9,10 fMRI studies indicate that the effects on the brain of acupuncture needling involve many centres, including the limbic system.11,12
A vast body of scientific literature exists that supports the hypothesis that acupuncture needling induces a chain of events that results in the release into various parts of the nervous system of neurotransmitters and neurohormones that have widespread and measurable effects on pain. The first of these studies was published in 1976 by Professor Bruce Pomeranz at the University of Toronto showing that acupuncture induced analgesia in anesthetized cats that resulted in decreased activity in the spinothalamic tract of the spinal cord, The effects were reversible by naloxone, which blocks morphine. 13 This implied that the effects were mediated by endogenous peptides, or ‘home-brewed narcotics’, as one writer described them.14
Endogenous peptides are what are popularly known as ‘endorphins’, a word that puts the concept that they are made endogenously, meaning by the body itself and not introduced from outside, together with the word ‘morphine’ to acknowledge that they share many effects with morphine. Probably best known for their possible link to ‘runner’s high’, endorphins clearly have a major role to play in the body’s handling of pain and are involved in addiction to heroin, morphine and other ‘opioids’, drugs that are derived from opium.
Since 1976, research has shown that acupuncture blocks pain transmission in the central nervous system by at least 3 different mechanisms. It is postulated that acupuncture needles stimulate type II and type III muscle afferent nerves or A delta fibers in the skin, sending signals to the anterolateral tract of the spinal cord. This blocks pain by releasing enkephalin and dynorphin, two of several peptides (chains of amino acids referred to generically as ‘endorphins’, as mentioned above). The released enkephalin and dynorphin prevent pain messages from ascending to the brain via the spinothalamic tract in the spinal cord.
Next, some impulses generated by the acupuncture stimulus reach the midbrain, the first part of the brain, just above the spinal cord. This causes a cascade of signals down the spinal cord via the dorsolateral tract, releasing norepinephrine and serotonin in the spinal cord. These neurotransmitters can inhibit pain in the spinal cord by blocking transmission of pain signals via the spinothalamic tract. Finally, other impulses from the acupuncture stimulus reach the pituitary-hypothalamic complex and cause the release of ß-endorphin into the bloodstream from the pituitary gland. This is accompanied by the release, on an equimolar basis, of adrenocorticotropic hormone (ACTH).15
There is some exciting research that shows what actually happens in tissues when an acupuncture needle is inserted and manipulated. This is a body of published work by Dr. Helene Langevin at the University of Vermont. To sum up her hypothesis, it is possible that the mechanical signal created by an acupuncture needle being rotated in the plane of loose connective tissue at an acupuncture point can be transduced into an electrical signal that is passed through the web of fibroblasts in the body’s connective tissue, that may correspond to the meridian system. This may explain remote effects of acupuncture.16,17,18
See http://www.uvm.edu/annb/faculty/langevin/ for access to some of Dr. Langevin’s research papers.
The traditional understanding of acupuncture is that it creates balance in the body, expressed as the yin/yang relationship in traditional terms and by the term ‘homeostasis’ in western terms. A recent functional MRI study has shown that there is a different response by the brain when acupuncture is applied in individuals with carpal tunnel syndrome and in healthy control subjects, supporting the theory that acupuncture creates balance.19