Magnetic therapy is the use of magnets and the electromagnetic fields they generate to stimulate the body’s own healing processes. Magnetic therapy is currently used in over 50 countries world-wide, including the US, UK, Germany, Israel, Russia and Japan, where magnetotherapy has been studied for decades.
I am a great fan of magnetic therapy for relieving all types of muscle and joint pain and have recommended it in clinical practice for over twenty years with excellent results. Magnetic therapy is now used in mainstream medicine to stimulate blood flow, reduce pain and hasten the healing of damaged tissues.
Within the UK, a static magnetic device in the form of a leg wrap has been available since 2006 for NHS doctors to prescribe in the treatment of painful, chronic leg ulcers. It was so effective in clinical trials that ulcer area was reduced by an average of 91.2% over 12 weeks while ulcer size continued to increase in those using an identical but non-magnetic wrap. What’s more, none of the leg ulcers recurred in those using the magnetic therapy.
Magnetism is a natural phenomenon in which certain materials can attract or repulse each other. This effect arises because atoms are made up of a positively-charged nucleus, surrounded by negatively-charged, orbiting electrons. The moving electrons produce a small electric current which, in turn, generates a magnetic field.
If the electrons are present in pairs, these spin in opposite directions and the magnetic fields they produce cancel each other out. If one or more electrons are unpaired, however, they spin in a haphazard manner that produces a magnetic field.
Iron atoms have three unpaired electrons spinning around its central nucleus and can produce a particularly strong permanent magnetic field when they are aligned in the same direction.
Lodestone (magnetite) is an iron rich ore (Fe304) that has become magnetised by lying in the Earth’s magnetic field for millions of years.
In medieval times, blacksmiths discovered that iron bars could be magnetised if they were heated and then aligned in a north-south direction and beaten with a hammer as they cooled. Iron can also be magnetised by subjecting it to an electric field.
In the 1700s, carbon steel was found to retain its magnetism better than plain iron, and in the 1930s, magnets containing iron mixed with aluminium, nickel and cobalt were developed.
Rare earth magnets
Modern rare earth magnets are made using metallic elements in the rare earth group of the periodic table, such as neodymium. These magnets are considerably lighter and more powerful than traditional iron or steel magnets, and are much smaller in size.
Therapeutic rare earth magnets usually consist of an alloy containing iron, neodymium, and boron. They can be worn discreetly, applied to the body using an adhesive patch, or worn as jewelry. This is more convenient than using the traditional, heavy iron magnets that were strapped to the body with belts and bands.
The electromagnetic fields used in static magnetic therapy may be generated by single or multiple magnets, and those available for home use include adhesive magnetic patches, magnetic necklets and bracelets, wraps and mattress pads. Static magnets are also inserted as shoe insoles, joint wraps and hand gloves to treat painful parts.
Japanese researchers have estimated that static magnetic therapy has a success rate of 85% for producing clinically meaningful reductions in pain, which is considerably higher than for many pain-killling drugs, and with a significantly lower risk of side effects. Relief is usually rapid, with muscle pain often diminishing within 30 minutes of applying a therapeutic strength magnetic device.
Pulsed electromagnetic fields
Pulsed electromagnetic fields, also known as low field magnetic stimulation, generate an electromagnetic field using flat, spiral coils which is pulsed via a frequency generator.
I worked in orthopaedics for several years, and saw pulsed electromagnetic fields used to encourage stubborn bone fractures to unite. The success rate in stimulating formation of new bone is as high as 87%.
Pulsed electromagnetic fields have also been used successfully to reduce pain, inflammation and swelling after orthopaedic surgery on major joints such as rotor cuff repair of the shoulder, to aid clinical recovery following revision of hip replacement surgery, following arthroscopic surgery to knee cartilage and after total knee replacement.
Pulsed electromagnetic fields promote soft tissue healing after dental molar extraction, and, in one study, reduced post-surgical pain following Caesarean section. New mums receiving the active therapy needed only half the pain killing medication used by those given the sham therapy and, seven days after their Caesarean, active therapy produced better wound healing with no exudate, redness or swelling compared to sham therapy.
In people with osteoarthritis, pulsed electromagnetic therapy not only alleviates joint pain and stiffness, but also stimulates cartilage repair, has anti-inflammatory actions and promotes bone remodelling to make it a viable addition to standard arthritis treatment.
A review of data from 14 clinical trials, involving 930 people with osteoarthritis of the knee, showed that pulsed electromagnetic therapy was significantly more effective than placebo for improving knee function after 4 weeks treatment. In one study, involving 60 people with knee osteoarthritis, pulsed electromagnetic therapy (applied for 12 hours per day) significantly reduced pain to the extent that 26% stopped taking their non-steroidal anti-inflammatories or other analgesic treatments.
Another study, involving people with recurrent knee pain due to patellofemoral pain syndrome, showed that pulsed electromagnetic therapy reduced pain and led to a better recovery by improving their ability to take part in therapeutic exercises.
Deep electromagnetic stimulation has been used to treat chronic low back pain and shown to reduce pain intensity by half.
And in exciting new developments, electromagnetic field stimulation (EMF) has the potential to improve stem cell therapy, tissue engineering and the treatment of neurodegenerative diseases. Metal nanoparticles activated by EMF could also be used for drug delivery and wound dressings.
Those who still consider magnetic therapy a non-evidence based ‘woo’ treatment are way out of date!
How does magnetic therapy reduce pain?
The exact way in which magnetic therapy reduces pain is not fully understood, but recent research is unravelling some of the mechanisms involved in the rejuvenation and repair of damaged tissues. These include the stimulation of cell migration, proliferation and differentiation, expression of growth factors (eg to stimulate protein synthesis), nitric oxide signalling (which dilates blood vessels), cytokine modulation (to damp down inflammation) and more. These effects have even been detected during the application of low frequencies (30-300 kHz) and extremely low frequencies (3-30 Hz).
Every cell in your body generates its own electromagnetic field as charged particles (ions) move in and out of cells. This creates an electric potential across cell membranes that is vital for life, allowing cells to function, nerves and brain cells to transmit messages, and muscles to contract, as well as maintaining a regular heart beat.
Degenerative, painful conditions such as ostearthritis, joint misalignments associated with chronic back pain, and injuries such as muscle strains and ligament sprains all result in inflammation. inflammation alters the transport of ions and disrupts the cell’s natural electromagnetic field, which contributes to the pain, tenderness, swelling and stiffness you experience.
When therapeutic magnets are applied to the body, they produce physiological effects and are traditionally believed to restore health by helping cells regain their natural electromagnetic frequency. A growing body of research supports the following proposed mechanisms.
1 Magnetic therapy increases microcirculation
Magnetic therapy opens up tiny capillaries to increase the blood supply to the area, and with the blood comes extra oxygen and nutrients, as well as increased removal of cell wastes such as lactic acid.
In people with chronic diabetic foot ulcers, the use of pulsed electromagnetic field therapy (60 minutes, frequency12 Hz, intensity 12 Gauss) during 14 sessions over a 3 week period increased blood capillary diameter by 14% and blood flow velocity by 28%, while both measurements worsened in those receiving non-active sham therapy. After 3 weeks treatment there was a significant 18% decrease in wound size in those receiving active therapy, suggesting that pulsed electromagnetic field therapy can accelerate wound healing and improve microcirculation.
2 Magnetic therapy may stabilise pain receptors
Magnetic fields generated by magnetic therapy penetrate through the skin and underlying tissues to depths of up to 20mm, depending on magnet strength. This may stabilise pain receptors to reduce their activation and produce an analgesic effect. Electromagnetic field devices have been shown to suppress the production and effects of numerous chemicals involved in pain perception, and researchers who reviewed the evidence concluded there is strong evidence for the existence of a frequency-dependent interaction between electromagnetic field devices and cell signalling to suppress peripheral, inflammatory pain pathways.
3 Magnetic therapy may act like acupuncture
In Eastern medicine, life energy (chi or qi) is believed to flow through the body in channels known as meridians. Energy can enter or leave the body at a number of points along each meridian known as acupoints. These points have a lower electrical resistance than surrounding areas and can be pinpointed with great accuracy by measuring electrical potentials across the skin. Applying magnetic therapy over acupoints, or tender areas (tsuboes) may have effects on pain similar to those achieved with acupuncture. Correcting the flow of electromagnetic energy is thought to reduce the inflammation that irritates nerves to cause pain, and muscles to cause spasm.
A medical review of the use of magnets applied to acupuncture points in 42 studies, involving 6453 people, found that 37 studies (88%) reported a therapeutic benefit. The authors concluded that further investigation of acu-magnet therapy is warranted, especially in the management of diabetes and insomnia.
4 Magnetic therapy stimulates endorphin release
Like acupuncture, magnetic therapy stimulates the production of your own natural, opiate-like endorphins, to reduce pain perception. After exposure to a static magnet (3950 gauss) for fifteen minutes, blood endorphin levels increased by 25% after one hour, and were 45% higher two hours after exposure. A study involving 93 people with migraine found that trans-cranial magnetic stimulation significantly increased blood levels of endorphin, to reduce headache severity and frequency. Trans-cranial magnetic therapy also raised endorphin concentrations to provide long-lasting pain relief in people with phantom pain.
5 Magnetic therapy stimulates cell regeneration
Cell culture studies show that magnetic therapy can reduce the expression of inflammatory chemicals and boost their normal function, In bone and cartilage-producing cells, for example, the application of a pulsed electromagnetic field stimulates the production of growth factors, and allows cells to produce new extracellular material to stimulate the repair of damaged tissues. The researchers suggested that pulsed electromagnetic field therapy was a promising new treatment for people with osteoarthritis.
6 Magnetic therapy may regulate the activity of T-lymphocytes
T-lymphocytes play an important role in inflammatory responses and accumulate wherever there are unusual electromagnetic fields associated with inflammation. In order to ‘find’ inflammation, T-cells use positively-charged calcium ions to polarise themselves into tiny magnets. This attracts them towards the electromagnetic fields that form around damaged cells, damaged nerves, and which are also generated by pressure (piezoelectric currents) when bones rub together in arthritic joints. Once they arrive at an area of inflammation, T-lymphocytes release powerful chemical alarm signals (lymphokines) that attract other immune cells into the area. This ramps up the inflammation and makes the pain worse. Researchers have found that even a short exposure to magnetic fields can modify T-lymphocyte behaviour, so they don’t over-react and inflammation can resolve more quickly.
7 Magnetic therapy may regulate enzyme reactions
All metabolic reactions in the body are regulated by protein enzymes. Exposing plant enzymes to magnetic fields (ranging from 60 gauss to 20,000 gauss) for up to 25 hours increased the activity of some by 20% to 90% while suppressing the activity of others by around 25%. It is likely that magnetic therapy has similar effects on human enzymes, speeding up some reactions (eg to do with healing) and slowing others (eg to do with inflammation). Magnetic fields have already been shown to reduce the activity of the inflammatory enzyme COX-2, which is targeted by non-steroidal anti-inflammatory drugs such as ibuprofen.
Measuring magnetic force
The strength of a magnet was originally measured in units known as gauss (G). A magnetic field of one gauss is about twice the magnetic field at the Earth’s surface. The tesla (T) is a more modern unit, named after the late scientist, Nikola Tesla, used to measure higher strength magnetic fields. One tesla is equivalent to 10,000 gauss. Alternatively, 1 G = 0.1 mT.
A typical refrigerator magnet has a strength of 50 gauss, while the medical diagnostic technique of Magnetic Resonance Imaging typically uses fields of 10,000 to 30,000 gauss (1T to 3 T).
Magnets used in healing usually have field strengths ranging from 0.02 to 0.2 tesla – equivalent to 20 to 200 milliteslas (mT) and more usually labelled as 200 to 2000 gauss.
- Low gauss magnets have a strength of: 300 to 700 gauss
- Medium gauss magnets have a strength of: 800 to 2500 gauss
- High gauss magnets have a strength of greater than 2500 gauss
Different strengths of magnet are used for different applications, and a magnet with a high field strength is not necessarily more effective than one with a low field strength. However for optimum benefit, look for magnets with a gauss strength of 500 gauss or greater, as strengths below this appear to be less effective in clinical trials.
Traditionally, the north pole of a magnet was used to relieve and calm ‘hot’ pain due to inflammation and infection, while the south pole which has a more stimulatory effect, was used to relieve cold, aching types of pain such as that associated with poor circulation.
Modern produces may use different arrangements of magnets with different alignments of their magnetic poles to create different magnetic field patterns.
Magnetic therapy safety
According to the World Health Organisation, there are no known adverse effects to human health from exposure to static magnetic fields of up to 20,000 gauss.
However, magnetic therapy should not be used:
- where there is an infection
- in someone who has recently had chicken pox
- on open wounds (except under medical supervision)
- on someone with haemophilia
- on people fitted with a heart pace-maker or other electrical stimulators
- on people undergoing dialysis
- on people using an insulin pump or drug patch (except under medical supervision)
- on people with surgically implanted metal screws
- during pregnancy or while trying to conceive
Keep magnets away from computer discs and other magnetic media.
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