Acupuncture is an ancient form of Chinese medicine which practitioners believe can help with pain, anxiety, and many other health conditions. However, the evidence of its effectiveness is fairly sparse, making it a controversial topic in modern medicine. Read on to learn more.
What is Acupuncture?
Acupuncture is a form of alternative treatment for a wide array of disorders. This popular treatment can potentially mitigate pain, enhance mood and sleep, and improve the overall health and quality of life for an individual with few adverse side effects.
However, despite these miraculous indications, the medical and scientific community are skeptical about how it works, and whether it is safe and effective.
Many clinical and mechanical studies have produced conflicting results, making acupuncture not only a complex treatment to study but also a controversial, active area of research.
This post will explore how practitioners believe acupuncture works, as well as the pros and cons of acupuncture from a scientific standpoint.
History of Acupuncture
Acupuncture is one of the oldest practices in Traditional Chinese Medicine and is used to treat a variety of conditions. Acupuncture has been around for centuries and also has more recently become popular in Western countries [1].
It is thought to have originated in ancient China from about 6000 BCE and has spread throughout the world at various times. However, there are other alternative theories about the origins of acupuncture [2, 3].
Forms of Acupuncture
Acupuncture and Traditional Chinese Medicine create therapeutic effects through needling, pressure, or heat for certain medical conditions [4].
Traditional Chinese Medicine also involves ear acupuncture, moxibustion, scraping, cupping therapy, and the use of herbs. If the patient cannot or prefers not to use needles, a tuning fork is sometimes used to stimulate acupuncture points.
During acupuncture, thin metal needles are inserted at acupuncture points, or acupoints [5, 6].
These thin metal needles are briefly manipulated manually to penetrate the skin. The needles are then left in the skin for a period of time (30 minutes – hours). Some practitioners believe that electrical stimulation of the needle can enhance the stimulation of the acupoints [7].
The acupuncturists may also stimulate the points by either moving the needles up and down or rotating the needles [8].
Traditional
Although it originated in China, acupuncture has also been incorporated into other forms of traditional medicine, with some variations in nearby countries like Korea and Japan [9]. In Western countries, the Chinese form is generally practiced.
In traditional acupuncture, the practitioner examines the patient as a whole person, using cues such as complexion, body temperature, temperament, pulse, and tongue readings. Then, the practitioner treats the whole person’s pattern based on “Qi blockages” and organs that they believe need to be supported.
Most practitioners describe acupuncture as unblocking “Qi” or life energy to flow through “meridians.” These acupuncture points and meridians act as special conduits or paths for electrical signals to travel [10].
However, the theory that acupuncture works by moving Qi is controversial at best, because it does not fit within our current understanding of anatomy and physiology. There are many other alternatives but more sensible theories that explain why acupuncture is effective [11].
Traditional acupuncture has been indicated for a wide variety of conditions, including pain, infertility, hormonal problems, mood disorders, neurological disorders, skin problems, insomnia, allergies, digestive problems, and cancers [12].
Ear (Auricular)
Ear acupuncture (auricular)
Ear acupuncture is part of traditional acupuncture. It involves stimulation of precise points in the ear for specific therapeutic effects [13, 14].
Some researchers argue that ear acupuncture stimulates the vagus nerve and improves heart rate variability [15].
There are many theories that explain how ear acupuncture could work, including [16]:
- Traditionally, some practitioners believe that various regions of the ear correspond to an embryonic map of the body (this concept has no basis in science).
- The meridian theory, which contends that the ears are connected to 12 meridians.
- That the ears connect to branches of the vagus nerve called auricular branches of the vagus nerve and other facial nerves, which could be stimulated with acupuncture needles.
In rats, ear electroacupuncture had anti-inflammatory effects. This effect was reversed by blocking an acetylcholine receptor, but not opioid receptors. The researchers, therefore, suggested that vagus nerve stimulation by ear acupuncture could reduce inflammation via a cholinergic pathway [16].
Medical
Medical acupuncture is generally practiced by other medical practitioners that are not formally trained as acupuncturists. These could be physiotherapists, chiropractors, osteopaths, massage therapists, or medical doctors who take a short course (16 hours – 2 years) and obtain a certificate in medical acupuncture.
Generally, the purpose of medical acupuncture is only to relieve pain and restore functional mobility after an injury. Dry needling is used to lengthen shortened muscles and release trigger points [5]. Electroacupuncture on the muscles or near injured joints is used to stimulate blood flow to the area, flush out inflammation, and promote the correct function of the muscles [17]. Suction cups can also be used to bring more blood flow to the area and to release adhesions.
The use of needles specifically to release trigger points is not typically practiced in the context of traditional Chinese medicine.
Some medical acupuncture practitioners also put needles on some traditional meridian points to relieve pain and relax the patients. However, their scope of practice is typically only limited to the use of acupuncture to treat pain and not other generalized disorders that can be treated by fully-trained acupuncturists.
Moxibustion
Moxibustion is an external treatment that involves burning moxa (mugwort) wood or sticks on different points on the body in order to stimulate circulation [18].
Moxa is burned near an acupoint to cause a warm, painless sensation. This external treatment is widely used and believed to correct abnormal fetal position in pregnant patients. However, a systematic review found limited evidence to support this use [19, 20].
Moxibustion creates heat, which is believed to insulate the specific part of the body and stimulate acupoints. These effects induce the heat shock proteins (HSPs) in local tissues, causing vasodilation and increased blood flow [18].
The radiation effects of moxibustion allow the body to absorb energy from infrared waves and convert it to heat. This heat is believed to increase blood circulation and improve cellular and enzymatic metabolism [18].
Cupping Therapy
Cupping therapy involves utilizing a cup as a local suction on selected acupoints on the skin in order to manipulate blood flow (hyperemia and hemostasis) [21]. Traditionally, cups are placed on meridian points with the intent to release “stagnation” of the organs. However, cupping can also be used locally to relieve muscle tension and pain.
A cupping glass is applied to the skin and then withdrawn, creating a vacuum and trapping cool air under the cup [22].
The skin is then sucked into the cup, leading to heating and reddening of the affected skin area [23]. Given its mechanism of action, it is pretty common to have marks or bruises after the therapy, which should not be a worrying sign and will disappear within a couple of days. Anyone with a blood clotting disorder (like hemophilia) should talk to their doctor before undergoing cupping therapy, however.
Some researchers have proposed that cupping therapy could work by increasing local blood circulation and decreasing painful muscle tension. This process helps promotes microcirculation and local tissue repairs [22].
Traditional & Modern Uses
An anatomical study mapped these paths and found an 80% correlation between the sites of acupuncture points and connective tissue planes (fascial trigger points) [24].
Acupuncture is used to help a variety of symptoms and diseases including, but not limited to [1]:
- Acute infections and inflammation
- Involuntary bodily functions (autonomic nervous system)
- Pain
- Brain and movement disorders (PNS & CNS disorders)
Acupuncture is more commonly used for the mitigation of pain [25].
However, there are some drawbacks to acupuncture use. Although very rare, serious adverse effects sometimes do occur. 7-11% of all patients experience non-serious adverse effects [26].
Current Scientific Perspective & Research on Acupuncture
In 1980, the World Health Organization (WHO) recommended acupuncture as an alternative form of treatment for 43 different disorders. However, these indications were not validated through rigorous clinical trials at the time [27].
Inconsistent results and conclusions from clinical studies on acupuncture have made it a controversial subject in western medicine, with many skeptics [28, 29, 26].
Despite the controversy, acupuncture is growing in popularity due to the lack of serious side effects. In many cases, acupuncture is considered a relatively safe intervention [30].
Mechanism of Effect
One of the challenges in acupuncture research is how to study its mechanism of action. Over the years, many theories have attempted to explain how acupuncture works. However, most of these theories cannot explain the apparent effects of acupuncture [31, 27].
The premise behind acupuncture, according to practitioners, is the treatment of abnormal functions rather than abnormal structures. Acupuncture utilizes the complex connection between the brain and the heart to exert its effects [32].
Biophysical/Mechanical Hypotheses
Based on the mechanical explanation, acupuncture is based on the stimulation of acupuncture points or acupoints, which form a complex network connecting the surface of the body with the internal body structures [31].
Strings of acupoints are called a meridian. Anatomically, acupuncture stimulates the innervated, elastic tissues connecting every muscle and tissue in the body (fascia). These sensory tissues are capable of transmitting electrical signals throughout the body and can be externally manipulated [33].
Practitioners believe that meridians and acupoints have biophysical properties [4]:
- Electrical properties: conduction of nerve signals
- Acoustic properties: these specific regions transmit more sound than the rest of the body
- Thermal properties: higher temperatures around the meridian lines after acupuncture use
- Optical properties: the surface where the meridians and acupoints are located are said to be more “luminous” than others.
Effects on the Brain
Some researchers have concluded that acupuncture triggers the release of neurotransmitters in the brain including serotonin, opioids, and endorphins [34].
Serotonin release from the brain (upper brain stem region and hypothalamus) stimulates the release of natural pain-relieving substances (β-endorphin, enkephalin, endomorphin, and dynorphin). Serotonin is believed to be released upon stimulation by acupuncture, and this may help reduce pain and improve mood [35, 36, 37].
Acupuncture reduced stress in multiple studies, probably by stimulating the parasympathetic nervous system and reducing norepinephrine (a stress hormone and neurotransmitter) [38, 39]. It also stimulates the vagus nerve [40].
Some researchers have attributed the pain-suppressing effect observed during acupuncture to neural mechanisms. They have suggested that the inserted needle stimulates the pain nerve fibers (Aβ, Aδ, & C afferent fibers) creating a feeling of both soreness and numbness [41].
Does it Really Work?
Designing clinical trials on the efficacy of acupuncture treatment is difficult because it is almost impossible to create a valid control group. There are many challenges including the blinding nature of control studies and the creation of a placebo control group.
However, advances in blunt, telescopic needles and observer analyst blinding have improved the quality of acupuncture studies. To further improve upon these studies (reducing bias), “sham forms” or wrong needle placement/superficial penetration help produce a higher-quality placebo control group [42].
Acupuncture research for multiple indications is still an active area for future studies. Many current acupuncture studies have produced conflicting and inconsistent results [43].
These results are especially true for the acupuncture indication for pain. There are many studies suggesting that acupuncture is not an effective treatment for pain. These studies demonstrate that there is little to no improved efficacy when compared to the placebo control (sham) group [25, 44, 29, 45].
Other studies suggest that acupuncture is relatively more effective than the control groups [46, 47, 48].
A meta analysis found that acupuncture provides moderate improvements compared to the placebo control group, but only small improvements compared to the sham acupuncture group. Most patients felt better and recorded less pain with acupuncture (and sham acupuncture) than patients without acupuncture [45].
Like this study, many high-quality clinical studies have found that acupuncture and sham acupuncture were more effective at relieving symptoms than conventional acupuncture or no treatment. This finding suggests that acupuncture may be no more effective than placebo [49, 50].
In brain imaging studies, the study group (with true acupuncture) experienced different changes in their brain compared to those with sham acupuncture [51].
Interestingly, acupuncture also elicited physiological changes in multiple studies of animals [52].
Regardless of the studies and results of previous experiments, further in-depth studies and more evidence are needed to determine whether acupuncture really works.
Further Reading
- Part 2 of this series: 6 Scientific Benefits of Acupuncture (Pain, Sleep, Nausea).