Magnetic bracelet pain relief probably placebo effect - 12/17/04Magnetic bracelet pain relief probably placebo effect
NewScientist.com news service - Katharine Davis
Is the pain relief that magnetic bracelets appear to provide to people with conditions like osteoarthritis just one more example of the placebo effect?
Probably, suggests the latest study.
Attracted by the promise of cheap, safe pain relief, people around the world spent an estimated $5 billion on magnetic bracelets in 1999. "The public wants
medication with no side effects," says Mark Caselli of the New York College of Podiatric Medicine in the US, who has carried out work on the possible use of
magnets to treat heel pain.
Even if they do work, many questions remain unanswered, including what strength magnet is best, which conditions can be treated and how regularly the
bracelet should be worn.
But studies to answer these questions are hampered because people can easily determine whether they been given have a real magnetic bracelet or non-magnetic
placebo - either their bracelet sticks to their keys, or it does not.
To try to tackle this problem, a study led by Tim Harlow of the College Surgery in Cullompton, Devon, UK, used a second type of control bracelet.
Almost 200 people aged 45 to 80, all with osteoarthritis of the hip or knee, were given either a strongly magnetic bracelet, a non-magnetic one, or one which
was only weakly magnetic.
After 12 weeks of wearing the bracelets all day, all three groups reported less pain. The strong and weak magnet groups did report less pain than the
non-magnetic bracelet groups.
But there was no statistically significant difference between the strong and weak magnet groups, as would be expected if the magnetic bracelet did have an
actual physical effect.
Mark Winemiller of the Mayo Clinic in Rochester, Minnesota, believes a placebo is the most likely explanation. "Without a plausible, or even proposed,
mechanism, it's difficult for me to accept results as valid," he says. "The placebo effect is much more likely than any actual effect."
Caselli is a little more optimistic. "This is not conclusive proof that people should run out and buy magnets," he says. "But you shouldn't discount them
entirely - there may be a future use for them."
Journal reference: British Medical Journal (vol 329, p 1450)