Proponents of magnetic healing or
"magnet therapy" claim that magnetic fields have a positive physiological effect upon the
circulatory system of the body, primarily aiding healing by dilating blood
vessels and by pulling red blood cells (because hemoglobin contains
iron) and their oxygen to infected or otherwise injured sites in the
body, which supposedly stimulates healing. Another theory says that they help
to align molecules in the blood stream, allowing them to flow
more easily.
There is little or no scientific basis for claiming that external application of static magnetic fields is effective in treating bodily injury. Very few scientifically rigorous
studies have been conducted, and of those, only one showed any statistically
significant therapeutic benefit. The results of that study have not been
independently confirmed and are in dispute.
The study which showed positive results was a double-blind study conducted at the Baylor
College of Medicine in Houston, Texas. They study involved patients who had had polio as
children, and used both magnets and placebos placed on the knees
of these patients to test their effects on joint pain. Exposure to
the magnets was very brief (only 45 minutes), and there were questions
as to the design of the experiment, particularly in sample selection and in
the measurement of
patient response. Furthermore, the study was only a pilot study, and
not complete. Two later studies conducted by the New York College of
Podiatric Medicine and the VA Hospital of Prescott,
Arizona conducted more complete studies on the efficacy of magnets on foot and
lower back pain. Both studies found magnets had no better effect on pain
than placebo.
Physically, there is little basis for believing in the efficacy of magnets
for pain relief and healing of injuries. The magnets used in these
devices are only slightly stronger than refrigerator magnets, which oftentimes
have trouble holding more than a few sheets of paper to a metal surface.
This suggests that the fields generated by these magnets barely penetrate the
skin, let alone reach damaged sites within the body.
As to the claim that
magnetic "alignment" of molecules somehow changes the circulatory system, consider this:
physicists at the University of Nijmegen in The Netherlands applied a
10 Tesla magnetic field to a frog, and managed to levitate it. Once the magnet was turned off, the frog behaved perfectly normally, and showed no apparent well- or ill-effects.
A 10 Tesla field is far, far stronger than the small magnets sold by these companies, and even in the presence of that strong field, the frog experienced
no noticeable physiological changes. Of course, this is not proof that there
was none -- it was a physics experiment, not a biomedical one, and the frog's physiology was not tested following
the experiment.
However, human beings are routinely exposed to strong, penetrating magnetic fields in magnetic resonance imaging machines and, to my knowledge, patients
experience no physiological changes during the imaging procedure.
Unfortunately, the producers of magnetic therapy products cite only the results
of the Baylor study, and rely on anecdotal testimony or paid celebrity
endorsements to make their sales. After the United States government started prosecuting
manufacturers who claim specific therapeutic benefits of magnet therapy for
fraud, producers have now switched to using more legally vague language,
saying that their magnetic bracelets and shoe inserts
"promote health, comfort, and vitality." They are still sold just about everywhere, often by otherwise
reputable retailers, despite campaigns by groups like CSICOP and despite the utter lack of proven medical efficacy. Of course, there may be a therapeutic benefit
from even a placebo if wearing one of these devices produces a psychosomatic effect, but the larger question is
Is it ethical to produce something knowing it has no effect, and knowing it may inhibit a patient from seeking conventional and more effective pain relief?
As always, caveat emptor.
A slightly offtopic postscript: James Randi pointed out that
a manufacturer claiming to sell "unipolar magnets" should instead
apply for a Nobel Prize, since the discovery a of magnetic monopole would turn the physics world on its ear. Sadly, the manufacturer never did.
Sources: pulled together from various sources, including CSICOP (www.csicop.org), QuackWatch (www.quackwatch.org), www.randi.org, and www.eurekalert.org. This rant inspired by my reading an advert for the therapeutic benefits of water composed entirely of oxygen-18 -- all for only $29.95. A steal, considering www.isotope.com claims it
can only manufacture about 60 kilos of oxygen-18 per year....