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 conflicting results, making acupuncture not only a complex treatment to study but also a continual active area of research.
In this post, you’ll read about how 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 became popular in Western countries [R].
It is thought to have originated in ancient China from about 6000 BCE and have spread throughout the world at various times. However, there are other alternative theories about the origins of acupuncture [R, R].
Acupuncture involves placing thin metal needles at specific points called acupuncture points.
Different Forms of Acupuncture
Acupuncture and Traditional Chinese Medicine creates therapeutic effects through needling, pressure, or heat for certain medical conditions [R].
Traditional Chinese Medicine also involves ear acupuncture, moxibustion, scraping, cupping therapy, and the use of herbs. If the patient cannot or prefer not to use needles, a tuning fork is sometimes used to stimulate acupuncture points.
These thin metal needles are briefly manipulated manually to penetrate the skin before leaving the needles on for a period of time (30 minutes – hours). Electrical stimulation of the needle can enhance stimulation of the acupoints [R].
The acupuncturists may also stimulate the points by either moving the needles up and down or rotating the needles [R].
Although originating in China, acupuncture has also been incorporated into traditional medicines with some variations in nearby countries, including Korea and Japan [R]. In Western countries, generally, the Chinese form is 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 makes a diagnosis and treat the whole person’s pattern based on Qi blockages and organs that 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 [R].
However, the theory that acupuncture works by moving Qi is controversial because it cannot be explained by our current understandings of anatomy and physiology [R]. There are many other alternatives but more sensible theories that explain why acupuncture is effective.
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 [R].
Ear (Auricular) Acupuncture
Ear acupuncture has been shown to stimulate the vagus nerve and improve heart rate variability [R].
There are many theories that explain why ear acupuncture works, including [R]:
- (less scientific, see image above) Various regions of the ear correspond to an embryonic map of the body
- The meridian theory, that the ears are connected to 12 meridians
- That the ears have branches of the vagus nerve called auricular branches of the vagus nerve and other facial nerves, which could be stimulated with the needles
In rats, ear electroacupuncture has anti-inflammatory effects. This effect could be blocked by blocking an acetylcholine receptor, but not the opioid receptors. Possibly, vagus nerve stimulation by ear acupuncture reduces inflammation via a cholinergic pathway (note: vagus nerves are cholinergic nerves) [R].
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 restores functional mobility after an injury. Dry needling can lengthen shortened muscles and release trigger points [R]. Electroacupuncture on the muscles or near injured joints can bring more blood flow to the area, flush out inflammation, and stimulates the muscles to function correctly [R]. 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 are 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 is an external treatment that involves burning moxa wood or sticks on different points on the body in order to stimulate circulation [R].
Moxibustion is burned near an acupoint to cause a warm, painless sensation. This external treatment has been widely used to correct abnormal fetal position in pregnant patients [R].
However, a systematic review found limited evidence to support the use of moxibustion for correcting the abnormal fetal position in pregnant patients [R].
The mechanism of action for moxibustion is through thermal and radiation effects.
Moxibustion creates a thermal physical effect that insulates the specific part of the body and stimulates the (polymodal) receptors of acupoints. These effects induce the heat shock proteins (HSPs) in local tissues, causing vasodilation and increased blood flow [R].
The radiation effects of moxibustion allow the body to absorb energy from infrared waves and convert it to heat. This heat increases blood circulation and improves cellular and enzymatic activities such as metabolism [R].
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) [R]. Traditionally, cups are placed on meridian points to release stagnation of the organs. However, it can also be used locally to relieve muscle tension and pain.
The process of cupping therapy is the extraction of blood away from the body. A cupping glass is applied to the skin and then withdrawn, creating not only a vacuum but also trapping cool air under the cup [R].
The skin is then sucked into the cup, leading to heating and reddening of the affected skin area [R]. 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.
A potential mechanism of action of cupping therapy is increasing local blood circulation and decreasing painful muscle tension. This process helps promotes microcirculation and local tissue repairs [R].
An anatomical study mapped these paths and found an 80% correlation between the sites of the acupuncture points and connective tissue planes (fascial trigger points) [R].
Acupuncture is used to treat a variety of symptoms and diseases including, but not limited to [R]:
- Acute infections and inflammation
- Involuntary bodily functions (autonomic nervous system)
- Brain and movement disorders (PNS & CNS disorders)
Acupuncture is more commonly used for the mitigation and treatment of pain [R].
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 [R].
Current Scientific Perspective & Research on Acupuncture
In 1980, the World Health Organization (WHO) has 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 [R].
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 compared to conventional medicine [R].
How Acupuncture Works
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 why acupuncture is effective in treating so many different diseases [R, R].
The premise behind acupuncture 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 [R].
Biophysical/Mechanical Explanation of How Acupuncture Works
Base 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 [R].
Strings of acupoints constitute 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 [R].
The meridians and acupoints have biophysical properties [R]:
- Electrical properties: conduction of nerve signals
- Acoustic properties: these specific regions transmit more sound than the rest of the body
- Thermal properties: high-temperature around the meridian lines after acupuncture use
- Optical properties: the surface where the meridians and acupoints are located is brighter (has more light) than the rest of the body
The needle insertion, which will pull collagen fibers creating a mechanical signal, has two separate characteristics that lead to both local and remote therapeutic effects:
- Needle sensation, caused by needle manipulation, is perceived by the patient through the mechanical signal to the connective tissues [R].
- Needle grasp, caused by needle rotation, is perceived by the acupuncturist. During needle grasp, the acupuncturist adjusts the needle based on its placement, resistance, and movement [R].
How Acupuncture Affects the Brain and neurotransmitters
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). This helps reduce and alleviate the pain and improve mood [R, R, R].
Acupuncture reduces stress by stimulating the parasympathetic nervous system and reducing norepinephrine (a stress hormone and neurotransmitter) [R, R]. It also increases the vagus nerve tone, especially the ear points [R].
The pain-suppressing effect through acupuncture treatment is caused by neural mechanisms. The inserted needle stimulates the pain nerve fibers (Aβ, Aδ, & C afferent fibers) creating an intricate feeling of soreness and numbness [R].
Stimulation of different meridian or acupoints can enhance different brain regions [R].
Does Acupuncture Work?
Designing clinical trials on the efficacy of acupuncture treatment is difficult because it is difficult 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 quality placebo control group [R].
Despite these controls, acupuncture research for multiple indications is still an active area for future studies. Many current acupuncture studies have produced conflicting and inconsistent results [R].
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 no or little-improved efficacy when compared to the placebo control (sham) group [R, R, R, R].
A meta analysis found that acupuncture provides moderate improvements compared to the placebo control group, but only small improvements compared to sham acupuncture group. Most patients felt better and recorded less pain with acupuncture (and sham acupuncture) than patients without acupuncture [R].
Like this study, many high-quality clinical studies show that acupuncture and sham acupuncture are more effective at relieving symptoms than conventional acupuncture or no treatments. This suggests that acupuncture may be no more effective than placebo [R, R]. Interestingly, brain imaging studies show that the study group (with true acupuncture) have different changes in their brain from those with sham acupuncture [R].
Interestingly, acupuncture also elicits physiological changes in animals [R].
Regardless of the studies and results of previous experiments, further in-depth studies and more evidence are needed to validate the indications of acupuncture.
To Be Continued
Read part 2 of this series: 9 Proven Health Benefits of Acupuncture.