Magnet therapy

Definition: Technique using magnets and magnetic fields on or near the body.

Principal proposed uses:

•Static magnets: Pain relief

•Pulsed electromagnetic field therapy: Nonhealing bone fractures, osteoarthritis

Other proposed uses

•Static magnets: Carpal tunnel syndrome, edema, fatigue, insomnia, osteoarthritis, rheumatoid arthritis, scar tissue, sports and fitness support, surgery support, tinnitus

•Pulsed electromagnetic field therapy: Migraines, erectile dysfunction, multiple sclerosis

Overview

Magnet therapy is a pseudoscientific alternative therapy based on the claim that weak magnetic fields from ordinary magnets can improve health, especially in terms of pain relief. It has no grounding in accepted science and should not be confused with various forms of electromagnetic therapy that have shown actual medical potential, such as repetitive transcranial magnetic stimulation (rTMS or TMS). Long popular in Japan, magnet therapy gained popularity in the United States as golfers and tennis players utilized the virtues of magnets for the treatment of sports-related injuries. Magnetic knee, shoulder, and ankle, insoles, and mattress pads are widely available and are thought to provide myriad healing benefits. However, studies have refuted the idea that such products have any health benefits beyond the placebo effect.

Because research into bioelectromagnetics continues to develop, there is often confusion over terminology and scientific acceptance. Generally, "magnet therapy" refers to alternative practices and beliefs that lack scientific backing. However, the term may sometimes cover therapies that have been shown to have measurable biological effects but for which the medical use of those effects may be disputed. One example is pulsed electromagnetic field (PEMF) therapy, which has shown some potential in treating certain conditions but remains controversial. As techniques such as rTMS have gained acceptance in the medical community, there have been efforts to disassociate them from the broad category of magnet therapy to avoid legitimizing pseudoscientific practices.

Magnet therapy has a long history in traditional folk medicine. Reliable documentation indicates that Chinese doctors have believed in the therapeutic value of magnets for two thousand years or more. In sixteenth-century Europe, Paracelsus used magnets to treat a variety of ailments. Two centuries later, Franz Mesmer became famous for treating various disorders with magnets.

In the middle decades of the twentieth century, scientists in various parts of the world began performing studies on the therapeutic use of magnets. From the 1940s on, magnets became increasingly popular in Japan. Yoshio Manaka, one of the influential Japanese acupuncturists of the twentieth century, used magnets in conjunction with acupuncture. Magnet therapy also became a commonly used technique of self-administered medicine in Japan. For example, a type of plaster containing a small magnet became popular for treating aches and pains, especially among older adults. Magnetic mattress pads, bracelets, and necklaces also became popular, mainly among older individuals. During the 1970s, both magnets and electromagnetic machines became popular among athletes in many countries for treating sports-related injuries.

These developments led to a rapidly growing industry creating magnetic products for a variety of conditions. However, the development of this industry preceded any reliable scientific evidence that static magnets actually work for the purposes intended. In the United States, it was only in 1997 that properly designed clinical trials of magnets began to be reported. While results of several preliminary studies suggested that some forms of electromagnetic therapy may indeed offer therapeutic benefits for certain disorders—escalating interest in magnet therapy—research consistently showed no health benefits from static magnets.

Therapeutic magnets come in two types of polarity arrangements: unipolar magnets and alternating-pole devices. Magnets that have north on one side and south on the other are known, rather confusingly, as unipolar magnets. Bipolar or alternating-pole magnets are made from a sheet of magnetic material with north and south magnets arranged in an alternating pattern so that both north and south face the skin. This type of magnet exerts a weaker magnetic field because the alternating magnets tend to oppose each other. Each type of magnet has its own recommended uses and enthusiasts. (There are many heated opinions, with no supporting evidence, on this matter.)

Mechanism of Action

The term “magnet therapy” usually refers to the use of static magnets placed directly on the body, generally over regions of pain. Static magnets are either attached to the body by tape or encapsulated in specially designed products, such as belts, wraps, or mattress pads. Static magnets are also sometimes known as permanent magnets.

Many commercial magnets have such a weak magnetic field that it is hard to believe they could affect the body at all. Some, however, are quite powerful and could conceivably cause effects at some depth. Nonetheless, biophysicists are skeptical that static magnets could significantly affect the body. (The moving magnetic fields of rTMS and PEMF act differently, and there is little doubt that they can affect nerve tissue and possibly other parts of the body.)

A commonly held misconception is that magnets attract the iron in blood cells, thus moving the blood and stimulating circulation. However, the iron in the blood is not in a magnetic form. Static magnets could affect charged particles in the blood, nerves, and cell membranes or subtly alter biochemical reactions, although whether the effect is strong enough to make a difference remains to be shown. Some research results suggest that static magnets affect local blood circulation, but a rigorously designed double-blind trial found that commercially available static magnets have no effect on blood flow. Another well-designed trial also failed to find effects on blood circulation.

Scientific Evidence

Static magnets. In double-blind, placebo-controlled trials, static magnets have shown no proof of health benefits. In a review of studies of static magnets as a treatment for pain, researchers concluded that there is no meaningful evidence that they are effective. They further concluded that evidence suggests that, for some pain-related conditions, static magnets are not effective (a much stronger statement than the first).

Some magnet proponents claim that it is impossible to carry out a truly double-blinded study on magnets because participants can simply use a metal pin or a similar object to discover whether they have a real magnet or not. Some researchers have gotten around this by using a weak magnet as the placebo treatment. Other researchers have designed more complicated placebo devices that participants have been found unable to identify as fake treatments.

A few studies have been interpreted by proponents of magnet therapy that the technique could have pain-reducing qualities for conditions, such as rheumatoid arthritis, osteoarthritis, and fibromyalgia. However, such studies have been widely criticized for being too limited or having problems with structure or objectivity. Many researchers have also noted that the subjective qualities of pain make it difficult to study. The US National Center for Complementary and Integrative Health (NCCIH) maintains that static magnets have not been shown to treat pain.

Many studies show that magnetic therapy provides no results that cannot be attributed to the placebo effect. One study tested magnet therapy for reducing muscle soreness after intense exercise. However, while the use of magnets did reduce muscle soreness, so did placebo treatment, and there was no significant difference between the effectiveness of magnets and placebo. Another study of more complex design also failed to find benefit. Magnetic insoles have been advocated for increasing sports performance. However, a study of fourteen college athletes failed to find that magnetic insoles improved vertical jump, bench squat, forty-yard dash, or performance of a soccer-specific fitness test.

Pulsed electromagnetic field therapy. Pulsed electromagnetic field therapy (PEMF) is quite distinct from more traditional magnet therapy itself. (The term “electromagnetic field” does not, in this case, refer to magnetism in the ordinary sense.) Nonetheless, for historical reasons, PEMF is often classified with true magnetic therapies. Unlike magnet therapy, as it is popularly known, PEMF has shown some potential in treating certain conditions.

Bone has a remarkable capacity to heal from injury. In some cases, though, the broken ends do not join, leading to what is called nonunion fractures. PEMF therapy has been used to stimulate bone repair in nonunion and other fractures since the 1970s; this is a relatively accepted use. More controversially, PEMF has shown promise for osteoarthritis, stress incontinence, and possibly other conditions.

Osteoarthritis. Three double-blind, placebo-controlled studies enrolling more than 350 people suggest that PEMF therapy can improve symptoms of osteoarthritis. For example, a double-blind, placebo-controlled study tested PEMF in eighty-six people with osteoarthritis of the knee and eighty-one people with osteoarthritis of the cervical spine. Participants received eighteen half-hour sessions with either a PEMF machine or a sham device. The treated participants showed significantly greater improvements in disease severity than those given placebo. For both osteoarthritis conditions, benefits lasted for a minimum of one month after treatment was stopped.

A later double-blind trial evaluated low-power, extremely low-frequency PEMF for the treatment of knee osteoarthritis. A total of 176 people received eight sessions of either sham or real treatment for two weeks. The results showed significantly greater pain reduction in the treated group. However, a research review found that it was unclear whether pain reduction by electromagnetism for osteoarthritis was significant enough to actually improve patients' daily functioning and quality of life.

Urinary incontinence. Many women experience stress incontinence, the leakage of urine following any action that puts pressure on the bladder. Laughter, physical exercise, and coughing can all trigger this unpleasant occurrence. One study suggests that PEMF treatment might be helpful. In this placebo-controlled study, researchers applied high-intensity pulsating magnetic fields to sixty-two women with stress incontinence. The intention was to stimulate the nerves that control the pelvic muscles.

The results showed that one session of magnetic stimulation significantly reduced episodes of urinary leakage over the following week, compared with placebo. In the treated group, 74 percent experienced significant improvement, compared with only 32 percent in the placebo group. Presumably, the high-intensity magnetic field used in this treatment created electrical currents in the pelvic muscles and nerves. This was confirmed by objective examination of thirteen participants, which found that magnetic stimulation was increasing the strength of closure at the exit from the bladder. However, there was one serious flaw in this study: it does not appear to have been double-blind. Researchers apparently knew which participants were getting real treatment and which were not and, therefore, might have unconsciously biased their observations to conform to their expectations. Thus, the promise of electromagnetic therapy for stress incontinence still needs to be validated in properly designed trials.

Similarly, magnetic stimulation has been studied for the treatment of bed-wetting (nocturnal enuresis). In a small preliminary study, the use of PEMF day and night for two months was helpful in girls.

Multiple sclerosis. A two-month, double-blind, placebo-controlled study of thirty people with multiple sclerosis was conducted using a PEMF device. Participants were instructed to tape the device to one of three different acupuncture points on the shoulder, back, or hip. The study found statistically significant improvements in the treatment group, most notably in bladder control, hand function, and muscle spasticity. Benefits were seen in another small study as well. However, more data is needed before conclusions can be broadly applied.

Erectile dysfunction. In a three-week, double-blind, placebo-controlled trial, twenty men with erectile dysfunction received PEMF therapy or placebo. The magnetic therapy was administered by means of a small box worn near the genital area and kept in place as continuously as possible during the study period; neither participants nor observers knew whether the device was activated or not. The results showed that the use of PEMF significantly improved sexual function compared with placebo.

Migraines. In a double-blind trial, forty-two people with migraine headaches were given treatment with real or placebo PEMF therapy to the inner thighs for one hour, five times per week for two weeks. The results showed benefits in headache frequency and severity. However, the study design was rather convoluted and nonstandard, so the results are difficult to interpret.

Postoperative pain. In a small, randomized trial, eighty women undergoing breast augmentation surgery were divided into three groups. The first group received PEMF therapy for seven days after surgery to both breasts, the second group received fake PEMF therapy to both breasts as a control, and the third group received real and fake PEMF therapy to either breast. Compared to the control, women receiving PEMF therapy reported significantly less discomfort and used less pain medications by the third postoperative day. An early 2020s review of seven studies focusing on pain relief found that positive results were more common among patients with certain types of pain. For example, the results of pain relief in individuals with sciatica experienced more pain relief from magnet therapy than those with fibromyalgia.

How to Use Magnet Therapy

Among proponents of magnet therapy, there are a number of theories on the best size and type of magnets to use and where to apply them based on the type of condition being treated and other factors. Because unipolar magnets have greater depth of magnetic field penetration, some enthusiasts consider these more effective in treating deeper tissues. Conversely, it is considered that alternating-pole magnet devices might be more effective at stimulating surface tissue. Thus, it might be appropriate to use a unipolar high-gauss magnet for low back pain that originates deep in the tissue and an alternating-pole configuration for an injury closer to the surface, such as a wrist sprain. However, there is no meaningful scientific evidence to support these distinctions.

Additionally, some practitioners hold that the north side of the magnet calms and the south side excites and that using the correct side of the magnet is crucial. However, from a scientific perspective, it is difficult to see how there could be any difference between the two poles of the magnet in terms of the effect on body tissue.

There is general consensus that the magnet should be placed as close to the affected part of the body as possible. This can be done by taping the magnet to the skin, slipping the magnet inside a bandage over the affected area, or using a wrap device that has embedded magnets. Taping magnets to the body might irritate the skin. Additionally, some practitioners suspect that the body may adapt to the magnetic field over time, reducing the therapeutic effect. To prevent irritation and accommodation, practitioners usually recommend intermittent use, such as five days on, two days off, or twelve hours on, twelve hours off.

A wide range of magnetic devices are available, though most are not approved as medical devices and have no demonstrated health benefits. These may range from decorative jewelry, such as bracelets, to specialized products, such as shoe insoles. For treating large areas of the body, wraps and belts containing magnets are available. Wraps are specifically designed for the wrist, elbow, knee, ankle, neck, shoulder, and back, and are often made from thermal material to have the added effect of warming the area. These wraps are often recommended in cases of injury and arthritis, where heat feels better. Proponents of magnet therapy often recommend the use of magnetic mattress pads and mattresses for people with problems affecting several areas of the body.

Safety Issues

Generally, magnets are safe, and the biggest risk appears to be skin irritation from any tape that is used to hold them in place. Magnetic resonance imaging (MRI) machines, for example, expose the body to gigantic magnetic fields, and extensive investigation has found no evidence of harm. However, during the MRI, a person is subjected to a high level of magnetism for a short period of time, whereas people who use static magnets daily or sleep on them every night are subjected to a low level of magnetism over a long period of time. It is not known whether this type of exposure has any deleterious effects. Nonetheless, one study, in which participants slept on a magnetic mattress pad every night for four months, found no side effects.

It was previously thought that persons with an implantable cardioverter-defibrillator (ICD) or a pacemaker should not use magnetic devices at all, but this recommendation has been adjusted. One study found that with the exception of magnetic mattresses and mattress pads, most magnets sold for therapeutic purposes do not interfere with the magnetically activated switches present in most pacemakers. Magnetic mattress pads can deactivate and alter the function of ICDs and pacemakers, but other therapeutic magnets are safe if kept six inches or farther from these devices.

There are theoretical concerns that magnets might be risky for people with epilepsy. Similarly, until the physiological effects of magnet treatments are better understood, pregnant women should avoid them.

Due to the pseudoscientific nature of traditional magnet therapy, patients may be at risk of scams or other fraud. Any claims of specific benefits or effects from static magnet healing products or services should be viewed skeptically. Also, if patients forego conventional medical treatment and rely on magnet therapy alone to treat a condition, they may be at risk of progression or complications of that condition. Magnet therapy should never substitute for care from a licensed medical professional.

Bibliography

Abd-Elsayed, Alaa, et al. “Neuromodulation for Pain Management in the Inpatient Setting: A Narrative Review.” Cureus, vol. 13, no. 3, Mar. 2021, p. e13892. doi:10.7759/cureus.13892.

Bretlau, L. G., et al. “Repetitive Transcranial Magnetic Stimulation (rTMS) in Combination with Escitalopram in Patients with Treatment-Resistant Major Depression.” Pharmacopsychiatry, vol. 41, 2008, pp. 41-47.

Chen, C. Y., et al. “Effect of Magnetic Knee Wrap on Quadriceps Strength in Patients with Symptomatic Knee Osteoarthritis.” Archives of Physical Medicine and Rehabilitation, vol. 89, 2008, pp. 2258-2264.

Colbert, A. P., et al. “Static Magnetic Field Therapy for Carpal Tunnel Syndrome.” Archives of Physical Medicine and Rehabilitation 91 (2010): 1098-1104.

Klaiman, P., et al. “Magnetic Acupressure for Management of Postoperative Nausea and Vomiting.” Minerva Anestesiologica 74 (2008): 635-642.

"Magnet Therapy." Memorial Sloan Kettering Cancer Center, 26 Feb. 2021, www.mskcc.org/cancer-care/integrative-medicine/herbs/magnet-therapy. Accessed 28 Aug. 2023.

"Magnetic Field Therapy." Michigan Medicine, University of Michigan, 3 Jan. 2022, www.uofmhealth.org/health-library/aa141392spec. Accessed 28 Aug. 2023.

"Magnets for Pain." National Center for Complementary and Integrative Health, US National Institutes of Health, Jan. 2023, www.nccih.nih.gov/health/magnets. Accessed 28 Aug. 2023.

Palermo, Elizabeth. "Does Magnetic Therapy Work?" Live Science, 12 Feb. 2015, www.livescience.com/40174-magnetic-therapy.html. Accessed 4 May 2020.

Pittler, M. H., E. M. Brown, and E. Ernst. “Static Magnets for Reducing Pain.” CMAJ: Canadian Medical Association Journal, vol. 177, 2007, pp. 736-742.

Wrobel, M. P., et al. “Impact of Low Frequency Pulsed Magnetic Fields on Pain Intensity, Quality of Life, and Sleep Disturbances in Patients with Painful Diabetic Polyneuropathy.” Diabetes and Metabolism, vol. 34, 2008, pp. 349-354.