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. 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. or with pulsed electromagnetic field therapy.

Methods of application

right|thumb|alt=A smooth circular band of magnetite on a finger|[[Magnetite ring]]

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.

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 and the application is usually performed by the patient. Tissue oxygenation is similarly unaffected.

Efficacy

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. Health claims regarding longevity and cancer treatment are implausible and unsupported by any research.

The American Cancer Society states that "available scientific evidence does not support these claims". 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.

A 2008 systematic review of magnet therapy for all indications found insufficient evidence to determine whether magnet therapy is effective for pain relief, 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.

Safety

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. including $300 million per year in the United States alone.

A 2002 U.S. National Science Foundation report on public attitudes and understanding of science noted that magnet therapy is "not at all scientific." 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.

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.

See also

References

  • 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