Template:Short description Template:About Template:Alternative medicine sidebar Magnetic therapy is a pseudoscientific alternative medicine practice involving the weak static magnetic field produced by a permanent magnet which is placed on the body. It is similar to the alternative medicine practice of electromagnetic therapy, which uses a magnetic field generated by an electrically powered device.<ref name=acsMag/> Magnet therapy products may include wristbands, jewelry, blankets, and wraps that have magnets incorporated into them.<ref name="acsMag" /><ref name="Pittler2008" />
Practitioners claim that subjecting certain parts of the body to weak electric or magnetic fields has beneficial health effects. These physical and biological claims are unproven and no effects on health or healing have been established.<ref name=acsMag/><ref name=Park_Voodoo>Template:Cite book</ref><ref name="Wanjek_BM">Template:Cite book</ref><ref name='NSF_SEIND_2006'>Template:Cite book</ref> Although hemoglobin, the blood protein that carries oxygen, is weakly diamagnetic (when oxygenated) or paramagnetic (when deoxygenated), the magnets used in magnetic therapy are many orders of magnitude too weak to have any measurable effect on blood flow.<ref name="Stick_perfusion" /> This is not to be confused with transcranial magnetic stimulation, a scientifically valid form of therapy,<ref>Template:Cite journal</ref> or with pulsed electromagnetic field therapy.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Methods of applicationEdit
Magnet therapy involves applying the weak magnetic field of permanent magnets to the body, for purported health benefits. Different effects are assigned to different orientations of the magnet.<ref name="isbn0-911311-14-9">Template:Cite book</ref>
Products include magnetic bracelets and jewelry; magnetic straps for wrists, ankles, knees, and back; shoe insoles; mattresses; magnetic blankets (blankets with magnets woven into the material); magnetic creams; magnetic supplements; plasters/patches and water that has been "magnetized". These products generally use neodymium and ferrite magnets<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and the application is usually performed by the patient.<ref name=acsMag/>
It is similar to the alternative medicine practice of electromagnetic therapy, which uses the weak electric or magnetic fields as well, but generated by electrically powered devices.<ref name=acsMag/>
Suggested mechanisms of actionEdit
Perhaps the most common suggested mechanism is that magnets might improve blood flow in underlying tissues. The field surrounding magnet therapy devices is far too weak and falls off with distance far too quickly to appreciably affect hemoglobin, other blood components, muscle tissue, bones, blood vessels, or organs.<ref name=Park_Voodoo /><ref name=FlammCSI2006 /> A 1991 study on humans of static field strengths up to 1 T found no effect on local blood flow.<ref name="Stick_perfusion">Template:Cite journal</ref><ref name="Polk_handbook">Template:Cite book</ref> Tissue oxygenation is similarly unaffected.<ref name=FlammCSI2006 /> Some practitioners claim that the magnets can restore the body's hypothetical "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. If the body were meaningfully affected by the weak magnets used in magnet therapy, MRI would be impractical.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
EfficacyEdit
Several studies have been conducted in recent years to investigate what role, if any, 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.<ref name="Finegold" /> Incomplete or insufficient blinding tends to exaggerate treatment effects, particularly where any such effects are small.<ref name="CONSORT_2001">Template:Cite journal</ref> Health claims regarding longevity and cancer treatment are implausible and unsupported by any research.<ref name=FlammCSI2006 /><ref name=BBC2006 /> More mundane health claims, most commonly about anecdotal pain relief, also lack any credible proposed mechanism and clinical research is not promising.<ref name=Pittler2008>Template:Cite journal</ref><ref name=Livingston1998 /><ref>Template:Cite journal</ref>
The American Cancer Society states that "available scientific evidence does not support these claims".<ref name=acsMag>Template:Cite book See archived online version {{#invoke:citation/CS1|citation |CitationClass=web }} Electromagnetic therapy is a related field. See chapter in ACS book just referenced, and archived ACS webpage on that.</ref> According to the National Center for Complementary and Integrative Health, studies of magnetic jewelry have not shown demonstrable effects on pain, nerve function, cell growth or blood flow.<ref>Template:Cite news</ref>
A 2008 systematic review of magnet therapy for all indications found insufficient evidence to determine whether magnet therapy is effective for pain relief,<ref name=Pittler2008 /> as did 2012 reviews focused on osteoarthritis and rheumatoid arthritis.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> These reviews found that the data was either inconclusive or did not support a significant effect of magnet therapy. They also raised concerns about allocation concealment, small sample sizes, inadequate blinding, and heterogeneity of results, some of which may have biased results.
SafetyEdit
These devices are generally considered safe in themselves, though there can be significant financial and opportunity costs to magnet therapy, especially when treatment or diagnosis are avoided or delayed.<ref name=BBC2006 /><ref name=Pittler2008 /> Use is not recommended with pacemakers, insulin pumps, and other devices that may be negatively affected by magnetic fields.<ref name="Pittler2008" />
ReceptionEdit
The worldwide magnet therapy industry totals sales of over a billion dollars per year,<ref name=FlammCSI2006>Template:Cite news</ref><ref name=BBC2006>Template:Cite news</ref> including $300 million per year in the United States alone.<ref name="Finegold">Template:Cite journal</ref>
A 2002 U.S. National Science Foundation report on public attitudes and understanding of science noted that magnet therapy is "not at all scientific."<ref name="mag_NSF">Template:Cite book "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."</ref> 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.<ref name=Livingston1998>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Legal regulationsEdit
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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
See alsoEdit
ReferencesEdit
External linksEdit
- Magnetic Therapy: Can magnets alleviate pain? by Cecil Adams — The Straight Dope
- Magnetic Therapy: Plausible Attraction? by James D. Livingston — Skeptical Inquirer
- Magnet therapy in the Skeptic's Dictionary by Robert Todd Carroll
- Magnet therapy — editorial in the British Medical Journal
- Magnet Therapy: A Skeptical View by Stephen Barrett — Quackwatch
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