Re: Magnets in relation to magnet therapy

Deborah: You ask whether there is research that supports the use of magnet therapy for multiple medical cures.

There are two major kinds of "magnet therapy"

• Pulsed magnetic fields created by electromagnets
• Static magnetic fields generated by permanent magnets

The use of static magnets for pain relief is very popular, but there is essentially no clinical or experimental data to support this use (see Valbona et al, 1999 and Trock, 2000). Many of the devices on the market are little more than expensive refrigerator magnets.

Most of the material on the Internet on magnet therapy seems to have been written by the sort of people who used to sell "snake oil" at county fairs. Among the credible sources I found are:

• Quackwatch [http://www.quackwatch.com/04ConsumerEducation/QA/magnet.html]
• The Skeptics Dictionary [http://dcn.davis.ca.us/~btcarrol/skeptic/ magnetic.html]
• Statistical Assessment Service [http://www.stats.org/statswork/magnet.htm]

• Ryaby, J. T. Clinical effects of electromagnetic and electric fields on fracture healing. Clinical Orthopaedics and Related Research. 1998; 355S:S205-S215.
• Otter, M. W.; McLeod, K. J., and Rubin, C. T. Effects of electromagnetic fields in experimental fracture repair. Clinical Orthopaedics and Related Research. 1998; 355S:S90-S104.
• Trock DH: Electromagnetic fields and magnets. Investigational treatment for musculoskeletal disorders. Rheumatic Diseases Clinics of North America. 26(1):51-62, 2000.
• Vallbona C., Richards T.: Evolution of magnetic therapy from alternative to traditional medicine. Physical Medicine and Rehabilitation Clinics of North America. 10(3):729-54, 1999.

John Moulder
Radiation Biologist
Medical College of Wisconsin