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Magnet therapy

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Magnet therapy, magnetic therapy, biomagnetics, or magnotherapy is a complementary and alternative medicine practice involving the use of static magnetic fields. Practitioners claim that subjecting certain parts of the body to static magnetic fields produced by permanent magnets has beneficial health effects, like pain relief, increased blood flow, and improved healing.

Magnet therapy was originally considered as pseudoscience, primarily due to inconsistent research findings.[1][2][3] However, more systematic research has confirmed that strong static magnetic fields from permanent magnets are able to constrict and dilate the walls of capillary blood vessels.[4][5] This reduces inflammation and increases blood circulation respectively.[6] Static magnet therapy has potentially effective applications in relief of pain and swelling after sports injury and blunt trauma, as well as wound healing after surgery.[7][8]

Description

A smooth circular band of magnetite on a finger.
Magnetite ring.

Magnet therapy is the application of permanent static magnets to the body for health benefits. These benefits may be specific, as in the case of wound healing and pain relief, or more general, as for increased energy and vitality. In the latter case, malaise is sometimes described as "Magnetic Field Deficiency Syndrome" and Electromagnetic Hypersensitivity.[9][10]

Magnetic therapy products include: magnetic supports and braces for wrists, ankles, knees, the back, and other body areas; magnetic bracelets and jewelry; magnetic shoe insoles; magnetic mattress pads; magnetic horse blankets (blankets with magnets woven into the material); magnetic pet beds; magnetic creams; magnetic supplements;[11] and water "magnetization" devices. Application is usually performed by the patient.[12]

Safety and Efficacy

Magnetic therapy devices are generally considered safe in themselves. Both doctors and magnetic practitioners warn that magnets should not be used by any person who has a pacemaker, defibrillator, insulin pump, or any similar implanted electro-medical device, as magnets can affect their operation.[13][14] Practitioners also caution that magnets should not be used during pregnancy. The potential health risks during fetal development are unknown. There can be significant financial and opportunity costs to relying on magnet therapy alone if proper medical treatment or diagnosis are avoided or delayed, particularly for severe medical conditions.[12][15]

Magnetic therapy may prove to be a very effective form of complementary and alternative medicine. Researchers suggest the ready availability and low cost of magnets used for pain relief and healing could produce huge gains in worker productivity and quality of life.[7] Magnetic therapy's long-term cost-effectiveness is also evident. In 2006 Britain's NHS began allowing magnets to be prescribed to better prevent and heal leg ulcers; potentially saving 153.7 million pounds per year in health care costs.[16]

Blood Microcirculation

Originally theorized to attract or repel the iron in hemoglobin, current research suggests that static magnetic fields actually affect Ca2+ ion channels.[6][17] Ion channels are key components in a wide variety of biological processes that involve rapid changes in cells, such as cardiac, skeletal, and smooth muscle contraction.

The primary mechanism of action of magnetic therapy is regulating blood microcirculation by relaxing or constricting the smooth muscle walls of capillaries.[4][5] This increases or decreases blood flow respectively. Static magnetic fields used in magnetic therapy do not affect blood circulation at the arterial level. This is shown in a 1991 study on NMR tomography, using static field strengths up to 1 T, found no effect on local blood flow in the forearms of humans subjects.[18][19]

Nerves and Pain Signals

Ion channels are also a key component of the nervous system for transmitting pain signals. Proponents of magnetic therapy suggest that magnetic fields may have an effect on restoring the balance of sodium, potassium, and/or chloride ions in nerve cells, reducing pain signals. This hypothesis is not yet proven. However, existing research supports the physiological effects of both electromagnetic and static magnetic fields on these particular ion channels.[20][21][22]

Practitioners assign different health effects based on the orientation of the magnet.[23][24] ; Under the laws of physics, magnetic poles are symmetric, though lines of induction (force) are emitted from one pole and enter another. Magnet therapists designate "bio-north" as the "negative" pole where lines of force enter, and "bio-south" as the "positive" pole where they exit.[25] Practitioners state the negative polarity is responsible for effects including: pain relief, reduction of swelling, speeding wound healing, promoting better sleep, improving depression, enhancing calcium metabolism, and fighting infection.[25][26] In the case of pain relief, there is scientific evidence noting that magnetic strength is not the only determining factor when using static magnetic fields to affect neurological activity.[27]

Inflammation & Healing

Funded by a grant from the NCCAM, an extensive research study using rats found that static magnetic fields were able to reduce inflammation by constricting capillaries.[6] This provides promising evidence, supporting a 1999 double-blind study that demonstrated magnets significantly reduced post-operative pain, bruising and swelling in liposuction patients during the first week of recovery. [8] A May 2009 research study also found that static magnetic fields were able to promote deep wound healing in rats.[28]

Researchers say magnets with proper field strength may potentially be more effective than ice packs and compression for treating swelling from sports injuries and recent trauma. [7] However, the fields surrounding some magnet therapy devices are far too weak and falls off with distance far too quickly to have a biological effect.[1][29] Tissue oxygenation is not directly affected by magnetic fields.[29] However, as blood flow increases, oxygen will be transported by red blood cells more efficiently.

General Health Claims

Some practitioners claim that the magnets can restore the body's "electromagnetic energy balance", though no such balance is medically recognized. In 2005, the World Health Organization issued a fact sheet for Electromagnetic Hypersensitivity, stating that electromagnetic field emissions from electronic technology (like televisions, computers and mobile phones) may have potential negative health effects, causing symptoms of fatigue, dizziness, concentration difficulties, nausea, and heart palpitations.[10] These symptoms are reminiscent of Magnetic Field Deficiency Syndrome. Originally proposed in 1957 by prominent magnetic field researcher Dr. Kyoichi Nakagawa, Magnetic Field Deficiency Syndrome is said to be caused by the earth's degrading natural magnetic field, combined with metal from buildings, automobiles, and other technology further reducing these natural fields.[30] While the symptoms are real, there is no clear scientific basis to link EHS symptoms to EMF exposure, as other environmental factors like "flicker" from fluorescent lights, poor air quality, or workplace stress may also contribute to these symptoms.[10] Static magnetic fields used in magnetic resonance imaging are considered safe.[31]

Health claims, such as longevity and cures for AIDS and cancer, are currently unsupported by any research.[15][29] However, a 2008 study found that exposure to static magnetic fields reduced blood microcirculation in cancerous tumors, citing new potential therapeutic strategies using strong magnetic fields.[32][33] More extensive research is still required in this area before any new treatment method can be developed and tested.

Research Reviews

Most reviews state that effects of magnet therapy on pain relief beyond non-specific placebo response have not been adequately demonstrated.

The most recent and comprehensive systematic review of research on magnet therapy, published in 2007, found no meaningful evidence of an effect for pain relief, with the possible exception of osteoarthritis.[34] The review concluded that:

"The evidence does not support the use of static magnets for pain relief, and therefore magnets cannot be recommended as an effective treatment. For osteoarthritis, the evidence is insufficient to exclude a clinically important benefit, which creates an opportunity for further investigation.

One possible explanation for these negative findings is provided by the National College of Natural Medicine in Portland, Oregon. Researchers state:

"The latest of 2 systematic reviews that assessed the efficacy of SMF [static magnetic field] therapy for pain reduction concluded that the evidence does not support the use of magnets for pain relief. We argue that this conclusion is unwarranted if the SMF dosage applied was inadequate or inappropriate for the clinical condition treated. Although in their review Pittler et al. applied strict criteria to include trials based on the quality of randomization, blinding, allocation concealment, and reporting of dropouts, they gave no consideration to the fundamental question of whether the intended SMF actually reached or was appropriate for the targeted tissue." [35]

A separate review of research literature concerning alternative medicine published in 2008 also concluded "On the basis of our findings, the evidence is not fully convincing for most complementary and alternative medicine modalities in relieving neuropathic or neuralgic pain. However, for topically applied capsaicin there is evidence of effectiveness beyond placebo. The evidence can be classified as encouraging and warrants further study for cannabis extract, magnets, carnitine, and electrostimulation."[36] However, this article did not directly consider any primary research evidence on magnet therapy, but used a single critical review published in 2005 as it's only source.

Placebo Effect

Several studies have been conducted in recent years to investigate what, if any, role static magnetic fields may play in pain relief and healing. Unbiased studies of magnetic therapy are problematic, since magnetization can be easily detected, for instance, by the attraction forces on ferrous (iron-containing) objects; because of this, effective blinding of studies (where neither patients nor assessors know who is receiving treatment versus placebo) is difficult.[37] Incomplete or insufficient blinding tends to exaggerate treatment effects, particularly where any such effects are small.[38]

In addition to double-blind studies, standardized research on animals and tissue samples, conducted both in vivo and in vitro, are also providing greater evidence for magnetic therapy. When testing animals or tissue samples, there is no placebo effect. For example, in 2004, a study from Japan found that static magnetic fields provided pain relief and reduced inflammation in rats with arthritis. The study monitored changes in measurements such as tail surface temperature (using thermography), locomotor activity (using a metabolism measuring system), serum inflammatory markers, and bone mineral density (using DEXA).[39] A 2008 experiment at the Division of Plastic Surgery of the University of Missouri Hospital, divided lab rats with cutaneous wounds into three test groups, each one using either a magnet, sham magnet, or nothing (control group). Results showed wounds in the magnet group healed significantly faster (average 5 days faster) than both the sham and control groups.[40]

Newer research studies are finding ways to better exclude the placebo effect in humans. At Harvard Medical School, a double-blind placebo-controlled trial used a new placebo-magnet device to conceal treatment and control group assignment. This pilot study found that the treatment group using static magnet therapy had statistically significant pain relief for knee osteoarthritis as compared to the control group after devices were worn for four hours. However there was no significant difference in pain outcomes between magnet and placebo groups at subsequent follow up, which happened after devices had been worn for 6 weeks.[41]

In 2009 the results of a randomized double-blind placebo-controlled crossover trial on the use of magnetic wrists straps (a leather strap with a magnetic insert) for osteoarthritis were published, addressing a gap in research evidence identified by the latest systematic review. This trial showed that magnetic wrist straps are ineffective in the management of pain, stiffness and physical function in osteoarthritis. The authors concluded that "Reported benefits are most likely attributable to non-specific placebo effects".[42][43]

Reception

Today in Japan and other Asian countries, therapeutic magnets are licensed as medical devices. Contemporary western medicine uses certain forms of magnetic energy for diagnosis, for example in magnetic resonance imaging (MRI), and PEMF as an aid to accelerate the healing process, following breaks and fractures in bone structure.[44] As of 2006, the worldwide magnet therapy industry totaled sales of over a billion dollars per year,[15][29] including $300 million dollars per year in the United States alone.[37]

Marketing of any therapy as effective treatment for any condition is heavily restricted by law in many jurisdictions unless all such claims are scientifically validated. In the United States, for example, U.S. Food and Drug Administration regulations prohibit marketing any magnet therapy product using medical claims.[45]

See also

References

  1. ^ a b Park, Robert L. (2000). Voodoo Science: The Road from Foolishness to Fraud. New York, New York: Oxford University Press. pp. 58–63. ISBN 0-19-513515-6. Not only are magnetic fields of no value in healing, you might characterize these as "homeopathic" magnetic fields. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  2. ^ Wanjek, Christopher (2003). Bad Medicine: misconceptions and misuses revealed from distance healing to vitamin O. Hoboken, New Jersey: John Wiley & Sons. pp. 1–253. ISBN 0-471-43499-X. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  3. ^ National Science Foundation, Division of Resources Statistics (2006-02). Science and Engineering Indicators, 2006. Arlington, VA. Chapter 7. {{cite book}}: Check date values in: |date= (help); Cite has empty unknown parameter: |coauthors= (help); Unknown parameter |nopp= ignored (|no-pp= suggested) (help)
  4. ^ a b Skalak TC (2007). "Chronic static magnetic field exposure alters microvessel enlargement resulting from surgical intervention". American Journal of Applied Physiology. 103 (2): 629–636. PMID 17478604. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  5. ^ a b Gmitrov J (2002). "Effect of 0.25 T static magnetic field on microcirculation in rabbits". Bioelectromagnetics. 23 (23): 224–9. PMID 11891752. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  6. ^ a b c Skalak TC (2008). "Acute exposure to a moderate strength static magnetic field reduces edema formation in rats". American Journal of Physiology: Heart and Circulatory Physiology. 294 (1): H50-7. PMID 17982018. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  7. ^ a b c Maki, Melissa (2008-01-02). "Biomedical Engineering Study Demonstrates the Healing Value of Magnets". U.Va. Today.
  8. ^ a b Man D (1999). "The influence of a permanent magnetic field therapy on wound healing in suction lipectomy patients: a double-blind study". Plastic and Reconstructive Surgery. 104 (7): 2261–6. PMID 11149796. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  9. ^ Sabadell, Miguel (1998-07). "Biomagnetic Pseudoscience and Nonsense Claims". Skeptical Inquirer. Retrieved 2009-09-27. {{cite journal}}: Check date values in: |date= (help); Cite has empty unknown parameter: |coauthors= (help)
  10. ^ a b c "Electromagnetic fields and public health: Electromagnetic Hypersensitivity". Fact Sheet No.296. World Health Organization. 2005-12-01. Retrieved 2009-11-17. {{cite news}}: Cite has empty unknown parameter: |coauthors= (help)
  11. ^ link titleMagnets for a Better Life
  12. ^ a b Singh, Simon (2008-04-08). "Are we being hoodwinked by alternative medicine? Two leading scientists examine the evidence". Daily Mail. Retrieved 2009-08-18. {{cite news}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  13. ^ Ryf S, Wolber T, Duru F, Luechinger R (2008). "Interference of neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators: an in vitro study". Technology and Health Care : Official Journal of the European Society for Engineering and Medicine. 16 (1): 13–8. PMID 18334784.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  14. ^ Pittler, Max H. (2008-03). "Static magnets for reducing pain". Focus on Alternative and Complementary Therapies. 13 (1): 5. Retrieved 2009-08-18. {{cite journal}}: Check date values in: |date= (help); Cite has empty unknown parameter: |coauthors= (help)
  15. ^ a b c "Magnet therapies 'have no effect'". BBC. 2006-01-06. Retrieved 2009-08-18. {{cite news}}: Cite has empty unknown parameter: |coauthors= (help)
  16. ^ Eccles N (2006). "Static magnets prevent leg ulcer recurrence: savings for the NHS?". British Journal of Community Nursing. 11 (3): S26-30. PMID 16607239. {{cite journal}}: Cite has empty unknown parameter: |coauthors= (help)
  17. ^ Okano H (2001). "Modulatory effects of static magnetic fields on blood pressure in rabbits". Bioelectromagnetics. 22 (6): 408–18. PMID 11536282. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  18. ^ Stick C (1991). "Do strong static magnetic fields in NMR tomography modify tissue perfusion?". Nuklearmedizin. 154: 326. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  19. ^ Polk, Charles (1996). Handbook of Biological Effects of Electromagnetic Fields. CRC Press. p. 161. ISBN 0849306418. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  20. ^ Mathie A, Kennard LE, Veale EL (2003). "Neuronal ion channels and their sensitivity to extremely low frequency weak electric field effects". Radiation Protection Dosimetry. 106 (4): 311–6. PMID 14690272.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  21. ^ Gorczyńska E, Wegrzynowicz R (1986). "Effect of chronic exposure to static magnetic field upon the K+, Na+ and chlorides concentrations in the serum of guinea pigs". Journal of Hygiene, Epidemiology, Microbiology, and Immunology. 30 (2): 121–6. PMID 3722807.
  22. ^ Lange K (2000). "Microvillar ion channels: cytoskeletal modulation of ion fluxes". Journal of Theoretical Biology. 206 (4): 561–84. doi:10.1006/jtbi.2000.2146. PMID 11013115. {{cite journal}}: Unknown parameter |month= ignored (help)
  23. ^ Rawls, Walter C.; Davis, Albert Belisle (1996). Magnetism and Its Effects on the Living System. Acres U.S.A. ISBN 0-911311-14-9.{{cite book}}: CS1 maint: multiple names: authors list (link)
  24. ^ Eccles Nyjon K. "The misery of Restless Legs Syndrome survey". Magnopulse LTD.
  25. ^ a b Singh Birla, Ghanshyam; Hemlin, Colette (1999). Magnet Therapy: The Gentle and Effective Way to Balance Body Systems. Rochester, VT: Healing Arts Press. pp. 42–43. ISBN 0-89281-841-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
  26. ^ Philpott, William H (2000). [www.alternativemedicine.com Magnet Therapy: Alternative Medicine.com Definitive Guide]. Tiburon, California: AlternativeMedicine.com Books. pp. 24–25. ISBN 1-887299-21-1. {{cite book}}: Check |url= value (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  27. ^ McLean MJ, Holcomb RR, Wamil AW, Pickett JD, Cavopol AV (1995). "Blockade of sensory neuron action potentials by a static magnetic field in the 10 mT range". Bioelectromagnetics. 16 (1): 20–32. PMID 7748200.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  28. ^ Shen JG (2009). "Effect of static magnetic field on deep wound healing of SD rats". China Journal of Orthopaedics and Traumatology. 22 (5): 371–4. PMID 19522401. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  29. ^ a b c d Flamm, Bruce L. (2006-07). "Magnet Therapy: a billion-dollar boondoggle". Skeptical Inquirer. Committee for Skeptical Inquiry. Retrieved 2009-08-18. {{cite news}}: Check date values in: |date= (help); Cite has empty unknown parameter: |coauthors= (help)
  30. ^ Nichols, Trent W. "Bioelectromagnetic Therapy of Fibromyalgia/Chronic Fatigue Immune Deficiency Syndrome and Magnetic Field Deficiency Syndrome/Electrical Sensitivity". Advanced Magnetic Research Institute. Retrieved 2009-11-18. {{cite news}}: Cite has empty unknown parameter: |coauthors= (help)
  31. ^ "Safety in Medical Imaging Procedures".
  32. ^ Strieth S (2008). "Static magnetic fields induce blood flow decrease and platelet adherence in tumor microvessels". Cancer biology & therapy. 7 (6): 814–9. PMID 18340115. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  33. ^ Markuze II, Ambartsumian RG, Piruzian LA (1972). "[Change in the concentration of K Na, Ca ions in the ascitic fluid of tumor-bearing animals following the action of a constant magnetic field]". Izvestiia Akademii Nauk SSSR. Seriia Biologicheskaia (in Russian). 2: 268–72. PMID 5022164.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  34. ^ Pittler MH (2007). "Static magnets for reducing pain: systematic review and meta-analysis of randomised trials". Canadian Medical Association Journal. 177 (7): 736–742. PMID 17893349. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  35. ^ Colbert AP (2008). "Static magnetic field therapy: dosimetry considerations". Journal of Alternative and Complementary Medicine. 14 (5): 577–82. PMID 18532897. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  36. ^ Pittler MH (2008). "Complementary therapies for neuropathic and neuralgic pain: systematic review". Clinical Journal of Pain. 24 (8): 731–3. PMID 18725953. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  37. ^ a b Finegold L, Flamm BL (2006). "Magnet therapy". BMJ. 332 (7532): 4. doi:10.1136/bmj.332.7532.4. PMC 1325112. PMID 16399710. {{cite journal}}: Unknown parameter |month= ignored (help)
  38. ^ Altman, DG (2001-04-17). "The revised CONSORT statement for reporting randomized trials: explanation and elaboration". Annals of Internal Medicine. 134 (8): 663–694. PMID 11304107. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  39. ^ Taniguchi N (2004 Sept.). "Study on Application of Static Magnetic Field for Adjuvant Arthritis Rats". Evidence-based Complementary and Alternative Medicine. 1 (2): 187–191. PMID 15480444. {{cite journal}}: Check date values in: |year= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  40. ^ Henry SL (2008). "The effect of magnetic fields on wound healing: experimental study and review of the literature". Eplasty: Journal of Burns and Wounds. 8: e40. PMID 18725953. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  41. ^ Wolsko PM (2004). "Double-blind placebo-controlled trial of static magnets for the treatment of osteoarthritis of the knee: results of a pilot study". Alternative therapies in health and medicine. 10 (2): 36–43. PMID 15055092. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  42. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.ctim.2009.07.002, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1016/j.ctim.2009.07.002 instead.
  43. ^ "Copper bracelets and arthritis". NHS Choices. 2009-10-19. Retrieved 2009-11-03. {{cite news}}: Cite has empty unknown parameter: |coauthors= (help)
  44. ^ "Magnet Therapy". Consumer Health Reviews. 2001. Retrieved 2009-11-22.
  45. ^ "Magnets". CDRH Consumer Information. Food and Drug Administration. 2000-03-01. Retrieved 2008-05-02.
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