Magnet therapy

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Magnet therapy, magnetic therapy, magnetotherapy 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 magnetostatic fields produced by permanent magnets has beneficial health effects. Magnet therapy is considered pseudoscientific due to both physical and biological implausibility, as well as a lack of any established effect on health or healing.[1][2][3] Although hemoglobin, the blood protein that carries oxygen, is weakly diamagnetic and is repulsed by magnetic fields, the magnets used in magnetic therapy are many orders of magnitude too weak to have any measurable effect on blood flow.[4]

Contents

[edit] Description

Magnet therapy is the application of the magnetic field of electromagnetic devices or permanent static magnets to the body for purported health benefits. These purported benefits may be specific, as in the case of wound healing, or more general, as for increased energy and vitality. In the latter case, malaise is sometimes described as "Magnetic Field Deficiency Syndrome".[5] Some practitioners assign different effects based on the orientation of the magnet.[6]

The modern magnet therapy industry totals sales of $300 million dollars per year in the United States[7] and sells, often with explicit health claims, products such as magnetic bracelets and jewelry; magnetic straps for wrists, ankles, and the back; shoe insoles, mattresses, and magnetic blankets (blankets with magnets woven into the material); and even water that has been "magnetized".

[edit] Legal regulations

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, as such claims are unfounded.[8]

[edit] Efficacy

Several studies have been conducted in recent years to investigate what, if any, role static magnetic fields may play in health and healing. Unbiased studies of magnetic therapy are problematic, since magnetisation 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.[9] Incomplete or insufficient blinding tends to exaggerate treatment effects, particularly where any such effects are small.[10]

  • A study on humans of static field strengths up to 1 T found no effect on local blood flow.[4][11]
  • A trial of magnetic therapy for the treatment of wrist pain from carpal tunnel syndrome and chronic low back pain did not find any health benefits above placebo.[12][13]
  • A 2003 Cochrane Review of carpal tunnel syndrome treatments found no improvement in symptoms over placebo or control.[14]
  • A randomized, double-blind, placebo controlled trial of 101 adults diagnosed with plantar heel pain carried out in year 2003 found no significant difference in outcome between use of active vs. sham magnets.[15]
  • A randomized controlled trial found a statistically significant effect using non-magnetic and weak magnetic bracelets as controls against strong magnets in the management of pain from osteoarthritis of the hip and knee. The study could not conclude whether the response was due to non-specific placebo effects.[16]
  • A 2007 study suggested that application of 10 or 70, but not 400 mT, static magnetic fields reduced histamine-induced edema formation in rats.[17]

[edit] Criticism

A 2002 U.S. National Science Foundation report on public attitudes and understanding of science noted that magnet therapy is "not at all scientific."[18] A number of vendors make unsupported claims about magnet therapy by using pseudoscientific and new-age language. Such claims are unsupported by the results of scientific and clinical studies.[19] Most criticisms include:

  • The typical magnet used produces insufficient magnetic field to have any effect on muscle tissue, bones, blood vessels, or organs.[1]
  • Some manufacturers claim that the magnets help to circulate the blood by interacting with the iron in hemoglobin, a major component of red blood cells. There is no indication that circulatory benefits would result even if some blood component were to couple strongly to magnetic fields.
  • Others claim that the magnets can restore the body's theorized "electromagnetic energy balance", but no such balance is medically recognized.
  • Even in the magnetic fields used in magnetic resonance imaging, which are many times stronger, none of the claimed effects are observed.[20]
  • There are claims that the south pole of a magnet acts differently on the body than the north pole.[21]
  • Many of the websites that promote the benefits of magnetic therapy belong to individuals and companies that profit from the sale of magnetic therapy products.

[edit] See also

[edit] 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." 
  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. 
  3. ^ [[National Science Foundation |National Science Foundation, Division of Resources Statistics]] (2006-02). Science and Engineering Indicators, 2006. Arlington, VA. Chapter 7. http://www.nsf.gov/statistics/seind06/c7/c7s2.htm#c7s2l3. 
  4. ^ a b Stick C; Hinkelmann K, Eggert P, Wendhausen H (1991). "Do strong static magnetic fields in NMR tomography modify tissue perfusion?". Nuklearmedizin 154: 326. 
  5. ^ Sabadell, Miguel (1998-07). "Biomagnetic Pseudoscience and Nonsense Claims". Skeptical Inquirer. http://www.csicop.org/si/9807/magnet2.html. Retrieved on 2009-02-19. 
  6. ^ Rawls, Walter C.; Davis, Albert Belisle (1996). Magnetism and Its Effects on the Living System. Acres U.S.A. ISBN 0-911311-14-9. 
  7. ^ Leonard Finegold (2006). "Magnet Therapy". British Medical Journal 332 (4): 4. doi:10.1136/bmj.332.7532.4. PMID 16399710. http://www.bmj.com/cgi/content/full/332/7532/4. 
  8. ^ "Magnets". CDRH Consumer Information. Food and Drug Administration. 2000-03-01. http://www.fda.gov/cdrh/consumer/magnets.html. Retrieved on 2008-05-02. 
  9. ^ Finegold, L. Flamm, B. (2006). "Magnet therapy". British Medical Journal (British Medical Association) 332: 4. doi:10.1136/bmj.332.7532.4. PMID 16399710. http://bmj.bmjjournals.com/cgi/content/full/332/7532/4?ehom. 
  10. ^ Altman, DG; KF Schulz, D Moher, M Egger, F Davidoff, D Elbourne, PC Gøtzsche, T Lang, CONSORT GROUP (Consolidated Standards of Reporting Trials) (2001-04-17). "The revised CONSORT statement for reporting randomized trials: explanation and elaboration". Annals of Internal Medicine 134 (8): 663–694. PMID 11304107. 
  11. ^ Polk, Charles; Elliot Postow (1996). Handbook of Biological Effects of Electromagnetic Fields. CRC Press. pp. 161. ISBN 0849306418. 
  12. ^ Carter R, Aspy CB, Mold J (January 2002). "The effectiveness of magnet therapy for treatment of wrist pain attributed to carpal tunnel syndrome". J Fam Pract 51 (1): 38–40. PMID 11927062. 
  13. ^ Collacott EA, Zimmerman JT, White DW, Rindone JP (2000). "Bipolar permanent magnets for the treatment of chronic low back pain: a pilot study". JAMA 283: 1322–5. doi:10.1001/jama.283.10.1322. PMID 10714732. 
  14. ^ O'Connor D, Marshall S, Massy-Westropp N (2003). "Non-surgical treatment (other than steroid injection) for carpal tunnel syndrome". Cochrane Database of Systematic Reviews 2003 (1): CD003219. doi:10.1002/14651858.CD003219. http://www.cochrane.org/reviews/en/ab003219.html. 
  15. ^ Winemiller Mark H, Billow Robert G, Laskowski Edward R, Harmsen W Scott (2003). "Effect of magnetic vs sham-magnetic insoles on plantar heel pain". Journal of the American Medical Association 290: 1474. doi:10.1001/jama.290.11.1474. PMID 13129987. http://jama.ama-assn.org/cgi/content/abstract/290/11/1474. 
  16. ^ Harlow T, Greaves C, et al. (2004). "Randomised controlled trial of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee". BMJ 329 (7480): 1450. doi:10.1136/bmj.329.7480.1450. PMID 15604181. http://www.bmj.com/cgi/content/abstract/329/7480/1450. 
  17. ^ Morris CE, Skalak TC (January 2008). "Acute exposure to a moderate strength magnetic field reduces edema formation in rats". Am J Physiol Heart Circ Physiol 294 (1): H50–7. doi:10.1152/ajpheart.00529.2007. PMID 17982018. 
  18. ^ National Science Board (2002). Science and Engineering Indicators – 2002. Arlington, Virginia: National Science Foundation. pp. ch. 7. ISBN 978-016066579-0. http://www.nsf.gov/statistics/seind02/c7/c7s5.htm.  "Among all who had heard of [magnet therapy], 14 percent said it was very scientific and another 54 percent said it was sort of scientific. Only 25 percent of those surveyed answered correctly, that is, that it is not at all scientific."
  19. ^ James D. Livingston. "Magnetic Therapy: Plausible Attraction?". Skeptical Inquirer. http://www.csicop.org/si/9807/magnet.html. 
  20. ^ "Safety in Medical Imaging Procedures". http://www.radiologyinfo.org/content/safety/mri_safety.htm. 
  21. ^ Eccles Nyjon K. "The misery of Restless Legs Syndrome survey". Magnopulse LTD. http://www.magno-pulse.com/restless_legs.php#introduction. 

[edit] External links

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