The ScienceBasedMedicine.org Reference Pages are reviews of topics relevant to science and medicine. Each consists of a concise overview of the topic from a scientific perspective, an index of the most relevant posts here on SBM, links to some external resources we recommend, and our summaries of the most interesting and important research. These pages are a work in progress, and we are actively developing them over the summer and fall of 2013, starting with acupuncture, chiropractic, homeopathy, and vaccines & autism.
Overview of Acupuncture
Acupuncture is the practice of placing very thin needles through the skin in specific locations of the body for the purpose of healing and relief of symptoms. This practice is several thousand years old and is part of Traditional Chinese Medicine. As practiced today it is often combined with other interventions, such as sending a small current of electricity through the needles or burning herbs on the acupuncture points (a practice called moxibustion).
Acupuncture has recently been transplanted to the West, riding the wave of tolerance for unscientific treatment practices marketed as “complementary and alternative medicine.” While advocates have been successful at pushing acupuncture into the culture, the scientific medical community has still not accepted the practice as a legitimate scientific practice.
1. Acupuncture is a pre-scientific superstition
Proponents often cite acupuncture’s ancient heritage as a virtue, but it is more of a vice. Acupuncture was developed in a pre-scientific culture, before anything significant was understood about biology, the normal functioning of the human body or disease pathology. The healing practices of the time were part of what is called philosophy-based medicine, to be distinguished from modern science-based medicine. Philosophy-based systems began with a set of ideas about health and illness and based their treatments on those ideas. The underlying assumptions and the practices derived from them were never subjected to controlled observation or anything that can reasonably be called a scientific process.
An example from Western culture of philosophy-based medicine was the humoral theory – the notion that health was the result of the four bodily humors being in proper balance while illness reflected one or more of the humors being out of balance. Treatments therefore sought to increase or decrease one or more of the humors (such as the practice of bloodletting) to re-establish balance. The humoral theory survived for several thousand years in Western societies, perpetuated by culture and the power of deception inherent in anecdotal evidence.
Acupuncture is based upon the Eastern philosophy of chi (also spelled qi), which is the Chinese term for the supposed life force or vital energy that animates living things. In Traditional Chinese Medicine (TCM) chi flows through pathways in the body known as meridians. Illness results from the flow of chi through the meridians being blocked, or by the two types of chi (yin and yang) being out of balance. Acupuncture is the practice of placing thin needles at acupuncture points, which are said to coincide with points at which meridians cross, to improve the flow and restore the balance of chi.
There is no more reason to believe in the reality of chi than there is in the four humors, or in the effectiveness of acupuncture than the effectiveness of bloodletting.
2. Acupuncture lacks a plausible mechanism
Centuries of advancement in our understanding of biology has made the notion of life energy unnecessary. Further, no one has been able to detect life energy or formulate a scientifically coherent theory as to what life energy is, where it comes from, and how it interacts with matter or other forms of energy. Within science, the vitalists lost the debate over a century ago. Without chi, there is no underlying basis for acupuncture as a medical intervention.
Recent attention given to acupuncture has attempted to bring it into the scientific fold by hypothesizing physical mechanisms for its alleged effects. For example, some proponents argue that the needles may stimulate the release of pain-killing natural chemicals, relax tense muscles, or inhibit the conduction of pain through counter-irritation.
These potential mechanisms, while more plausible than the non-existent chi, remain speculative. Further, they would only explain the very non-specific effect of acupuncture causing a temporary mild reduction in pain (no better than rubbing your elbow after accidentally banging it against something hard). Such mechanisms could not account for any of the medical claims made for acupuncture, or the alleged existence of acupuncture points.
Further, it is misleading to say that such mechanisms could explain “acupuncture.” Acupuncture is the needling of acupuncture points to affect the flow and balance of chi. Using needles to mechanically produce a temporary local counter-irritation effect is not acupuncture – even though it may be an incidental consequence of this practice and may have contributed to its perceived effectiveness.
3. Claims for efficacy are often based upon a bait-and-switch deception
The most common example of the “bait-and-switch” for acupuncture are studies that examined the effects on pain of electrical stimulation through acupuncture needles. This is not acupuncture – it is transcutaneous electrical stimulation (TENS), which is an accepted treatment for chronic pain, masquerading as acupuncture.
This is not a quibble. Science requires unambiguous definition of terms and concepts. If acupuncture is said to be something scientifically then it must have some specific and unique characteristics. In medicine that means it should have a specific mechanism of action – and it is that mechanism that we would call acupuncture. Electrical stimulation is no more acupuncture than if morphine were injected through a hollow acupuncture needle and then claimed that any resulting pain relief was due to “acupuncture.”
Further, during a typical acupuncture treatment there are many other incidental effects that may occur. The atmosphere is often relaxing, and practitioners typically will palpate the “acupuncture points” prior to inserting the needles, for example. Practitioners also provide their kind attention, which has a positive psychological therapeutic value. There are therefore many nonspecific subjective effects that could lead to clients feeling better, making the actual insertion of needles an unnecessary component.
Reports of acupuncture anaesthesia are also misleading. Independent investigation shows that patients having surgery under anaesthesia (dramatic reports of which are largely credited with acupuncture’s popularity in the West) reveal that patients were receiving morphine in the IV fluid. Other reports indicate that patient were experiencing great pain, but were simply instructed to remain quiet by the surgeon (a product of Eastern culture). There are no verified reports of acupuncture serving as effective anesthesia during surgery.
4. Clinical trials show that acupuncture does not work
The previous points are all reasons to be highly skeptical of the claims made for acupuncture, but they are all also trumped by the ultimate consideration – the direct scientific evidence. There is a surprisingly large published literature on the clinical effects of acupuncture. Most people are equally surprised to learn that the literature is essentially negative – probably because the press cherry picks apparently positive studies and uncritically re-prints the press releases of acupuncture proponents.
It is important to evaluate the literature as a whole to see what pattern emerges. The pattern that does emerge is most consistent with a null effect – that acupuncture does not work.
Controlled clinical trials of actual acupuncture (uncontrolled trials should only be considered preliminary and are never definitive) typically have three arms: a control group with no intervention or standard treatment, a sham-acupuncture group (needles are placed but in the “wrong” locations or not deep enough), and a real acupuncture group. Most of such trials, for any intervention including pain, nausea, addiction, and others, show no difference between the sham-acupuncture group and the true acupuncture group. They typically do show improved outcome in both acupuncture groups over the no-intervention group, but this is typical of all clinical trials and is clearly due to placebo-type effects. Such comparisons should be considered unblinded because patients knew whether they were getting acupuncture (sham or real).
The lack of any advantage of real- over sham-acupuncture means that it does not matter where the needles are placed. This is completely consistent with the hypothesis that any perceived benefits from acupuncture are non-specific effects from the process of getting the treatment, and not due to any alleged specific effects of acupuncture. In other words, there is no evidence that acupuncture is manipulating chi or anything else, that the meridians have any basis in reality, or that the specific process of acupuncture makes any difference.
More recent trials have attempted to improve the blinded control of such trials by using acupuncture needles that are contained in an opaque sheath. The acupuncturist depresses a plunger, and neither they nor the patient knows if the needle is actually inserted. The pressure from the sheath itself would conceal any sensation from the needle going in. So far, such studies show no difference between those who received needle insertion and those who did not – supporting the conclusion that acupuncture has no detectable specific health effect.
Taken as a whole, the pattern of the acupuncture literature follows one with which scientists are very familiar: the more tightly controlled the study the smaller the effect, and the best-controlled trials are negative. This pattern is highly predictive of a null-effect – that there is no actual effect from acupuncture.
Index of SBM posts about acupuncture
These are ScienceBasedMedicine.org articles with a strong focus on acupuncture. You can also browse these plus all other posts that are relevant to acupuncture on the acupuncture category page.
Outside Resources about Acupuncture
- Acupuncture: A History, by Stephen Basser, 1999
- Acupuncture, Magic, and Make-Believe, by George A. Ulett, March 2003
- Does Acupuncture Work for Pain? A review of modern acupuncture evidence and myths, particularly with regards to treating low back pain and other common pain problems, by Paul Ingraham, 2013
Summary of Key Research about Acupuncture
Ramey, DW (2000). A Review of the Evidence for the Existence of Acupuncture Points and Meridians. AAEP Proceedings, 46, 220-224.
A thorough review of published studies reveals that there is no evidence for the existence of either acupuncture points or meridians as discrete entities.
Vickers A, Goyal N, Harland R, Rees R (1998). Do certain countries produce only positive results? A systematic review of controlled trials. Control Clin Trials, 19(2), 159-66.
A review of published clinical trials in China and other countries found the following results:
In the study of acupuncture trials, 252 of 1085 abstracts met the inclusion criteria. Research conducted in certain countries was uniformly favorable to acupuncture; all trials originating in China, Japan, Hong Kong, and Taiwan were positive, as were 10 out of 11 of those published in Russia/USSR. In studies that examined interventions other than acupuncture, 405 of 1100 abstracts met the inclusion criteria. Of trials published in England, 75% gave the test treatment as superior to control. The results for China, Japan, Russia/USSR, and Taiwan were 99%, 89%, 97%, and 95%, respectively. No trial published in China or Russia/USSR found a test treatment to be ineffective.
This is important to the understanding of the acupuncture literature, as many of the positive studies are coming out of China. The unrealistically high percentage of positive studies makes the Chinese body of clinical literature very suspect.