The National Post
Magnet therapy? Puh-leeze
by Howard Fienberg
The huckster at a carnival invites you to be instantly healed by his magic wand. Fifty cents? "Sure," you think, "what can it hurt?" How about five dollars? Or 50? "Now, wait a minute," you say, "does this magic work? And if so, how?"
My feet hurt, so I was attracted by a similar offer of magic from a prominent shoe manufacturer. Its new magnetic shoe is "the first shoe with its own power supply," guaranteed to increase circulation, reduce fatigue and pain and improve my energy.
U.S. sales of healing magnets last year yielded as much as US$300-million. Is this really every pedestrian's dream? Do magnets really help?
The marketer of the magnetic shoe relies on the principle that the body can be affected by exposure to external magnetic fields." So, magnets can increase the flow of blood, thus boosting the healing process. This is a common claim that seems to be based on the misunderstanding of the iron present in your blood.
Physicist Robert Park pointed out in his recent book Voodoo Science that "the iron in hemoglobin molecules is in a chemical state that is not ferromagnetic." In plain English, magnets don't attract your blood. Have you ever been scanned in a magnetic resonance imaging (MRI) machine? It contains magnets fantastically more powerful than those used in magnet therapy. According to Dr. Stephen Barrett of Quackwatch ("your guide to health fraud, quackery, and intelligent decisions"), the MRI "can cause tiny changes that the equipment can detect but are temporary and have no known health effect." If magnets had a serious impact on your blood flow, an MRI scan would probably blow you to bits.
Proponents of quack medicine often attempt to add intellectual weight to their proclamations by prefacing them with the phrase "studies show" (a convenient way to attract interest when they haven't got a golf pro's endorsements to fall back on). But scientifically valid clinical trials have yet to discover any effect of physical effects from magnet therapy. Prominent in this case is a study from the January, 1997, Journal of the American Podiatric Medical Association that found magnetic insoles had no effect on heel pain. But that is all among scientists. How are we in the public supposed to evaluate magnets?
Well, the best way to start is to check your magnet's power yourself. Magnets used in magnet therapy differ little from your average refrigerator magnet. Physicist Robert Park found the magnetic field from these flimsy things can't penetrate a dozen sheets of paper before falling to the floor. If that is the case, how can you expect it to penetrate your shoe as well as the thick skin of your foot?
Lacking scientific evidence, can't we rely on the wisdom of the ancients? Magnet therapies were used for centuries by many cultures. Maybe they were on to something. But wasn't bloodletting the favourite tool of healers for centuries as well? The length of time people cling to a belief gives no indication of its veracity.
What about personal experience and anecdotal evidence? Why does magnet therapy seem to work for some people? MIT physicist James Livingston proposes that "the magnetic back braces used by many senior golfers may help ease their back pains through providing mechanical support, through localized warming, and through constant reminder to the ageing athletes that they are no longer young and should not overexert their muscles." None of which requires magnets, of course. In fact, the most recent study of magnet therapy for back pain, in the Journal of the American Medical Association this past March, "found no immediate or cumulative difference in the outcome measures of low back pain" between real and fake magnets.
Magnets generally act as a placebo -- they change our perceptions rather than our reality. We can fool ourselves out of minor aches, pains and fatigue if we believe this pill or that magnet will help.
So magnet therapy is more about imagination than physics. "Hocus-pocus," the carnival huckster tells you, and your pain is gone. The news-addled public has been driven to the belief that for each study pointing one way, another exists pointing in the opposite direction, mostly because it cannot adequately judge a study's meaning. But discerning science from pseudoscience does not always require a PhD -- just a little mental exercise. We are all capable of sifting through the promises of politicians and deciding between brands of peanut butter -- we just need to consider them skeptically.
Howard Fienberg is research analyst with the Statistical Assessment Service, a non-partisan non-profit organization.
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