Magnetic bracelets seem to provide “clinically useful” pain relief from osteoarthritis, UK investigators report.

Even after numerous studies, the effect of magnets on chronic pain is still not clear, Dr. Tim Harlow, at College Surgery in Cullompton, Devon, and his associates note in their paper in the December 18/25 issue of the British Medical Journal.

To try to resolve the uncertainty, the group tested magnets for controlling pain due to osteoarthritis of the hip and knee in 194 patients ranging in age from 45 to 80 years old.

The participants were randomly assigned to wear bracelets with a standard neodymium magnet with field strength of 170 to 200 mTesla, a weak magnet intended to produce 21 to 30 mTesla, or a “dummy” non-magnetic bracelet.

The change in a standard osteoarthritis index was significantly different between the standard and dummy magnet groups. The average score dropped from 10.7 to 7.8 in the standard group, and from 10.9 to 9.3 in the dummy group.

Changes in pain score were also significantly different between these two groups, the authors report.

Differences between the standard and weak magnets were not statistically significant - possibly because the strength of the weak magnets was found to range unintentionally between 21 and 169 mTesla.

About one third of participants in the standard and dummy groups correctly guessed their group assignment, often because they could see the bracelet exerted a magnetic force or not. That might have affected their perceptions that the device was or was not working.

Nonetheless, Harlow’s team concludes that reduction in the osteoarthritis index score with the standard magnet, as well as the difference between the standard-magnet and dummy-magnet groups, “is similar to that found in trials of frontline osteoarthritis treatments, including non-steroidal topical creams, oral nonsteroidal drugs (including cyclo-oxygenase 2 inhibitors) and exercise therapy.”

SOURCE: British Medical Journal, December 18/25, 2004.