Long
considered only a component of quack medicine, magnetic therapy has received a
boost from a recent study at the Baylor College of Medicine. Is it plausible?
by James D. Livingston
A
double-blind study at Baylor College of Medicine, published last November in
Archives of Physical and Rehabilitation Medicine (Vallbona 1997), concluded that
permanent magnets reduce pain in post-polio patients, and the results were
heralded in The New York Times and on Bryant Gumbel's Public Eye. PBS's Health
Week and Time magazine recently reported on the growing use of magnets by
champion senior golfers and other professional athletes to relieve pain.
Magnetic pain relief products are now sold in many golf shops, and ads for them
appear in national golf and tennis magazines. Long a significant component of
the health industry in Japan and China, magnetic therapy is becoming a more and
more visible part of the alternative-medicine boom in the United States and
Europe. Is it all just hokum, as many previously assumed, or is magnetic therapy
becoming scientifically respectable?
For
thousands of years, wonder and magic were associated with the mysterious forces
exerted by natural magnets -- magnetite-rich rocks, today called lodestones.
Many trace magnetic therapy back to Paracelsus (1493-1543), a physician and
alchemist who reasoned that since magnets have the power to attract iron,
perhaps they can also attract diseases and leach them from the body. Charles
Mackay, in Extraordinary Popular Delusions and the Madness of Crowds (1841),
says of Paracelsus that "his claim to be the first of the magnetisers can
scarcely be challenged." But Paracelsus was also aware of the important
role of the patient's mind in the process of healing (Buranelli 1975). He wrote,
"The spirit is the master, the imagination is the instrument, the body
is the plastic material. The moral atmosphere surrounding the patient can have a
strong influence on the course of the disease. It is not the curse or the
blessing that works, but the idea. The imagination produces the effect." Paracelsus
was apparently well aware of the placebo effect.
The development in eighteenth-century
England of carbon-steel permanent magnets more powerful than lodestones brought
renewed interest in the possible healing powers of magnets, and among those
interested was Maximilian Hell, a professor of astronomy at the University of
Vienna. Hell claimed several cures using steel magnets, but he was rapidly
eclipsed by a friend who borrowed his magnets to treat a young woman suffering
from a severe mental illness. The friend was Franz Anton Mesmer (1734-1815), and
Mesmer's success with the "magnets from Hell" led directly to his
widespread promotion of his theory of "animal magnetism." Although he
first used actual magnets, he later found he could "magnetize"
virtually anything -- paper, wood, leather, water -- and produce the same effect
on patients. He concluded that the animal magnetism resided in himself, the
various materials simply aiding the flow of the "universal fluid"
between him and the patients.
Mesmer became so successful in Paris
that in 1784 King Louis XVI established a Royal Commission to evaluate the
claims of animal magnetism, a commission that included Antoine Lavoisier and
Benjamin Franklin among its members. They conducted a series of experiments and
concluded that all the observed effects could be attributed to the power of
suggestion, and that "the practice of magnetization is the art of
increasing the imagination by degrees." Thomas Jefferson, arriving in Paris
soon after the Commission report, noted in his journal: "Animal magnetism
is dead, ridiculed."
Ridiculed, perhaps, but not dead.
Mesmer himself faded from public view, but "magnetizing" persisted in
various forms. Many early magnetizers evolved into students of hypnosis and
developed various forms of hypnotherapy. (The trance induced in many of Mesmer's
patients is thought to be what is now called a hypnotic trance, and most
dictionaries today list mesmerism as a synonym for hypnotism.) One American who
became interested in magnetic healing was Daniel David Palmer, who opened
Palmer's School of Magnetic Cure in Iowa in the 1890s. His ideas developed into
the system of hands-on therapy known as chiropractic. Others focused on hand
gestures without actual touch, an approach recently reborn as "therapeutic
touch." [See "Catching Up With Eighteenth Century Science in the
Evaluation of Therapeutic Touch, " by Thomas S. Ball and Dean D. Alexander,
this issue, p. 31] Mary Baker Eddy was "cured" by a magnetizer, but
she later became convinced that cures could best be achieved through prayer, and
founded Christian Science.
Most of these byproducts of mesmerism, like Mesmer himself, ceased to use actual magnets. But the development of electrical technology in the late nineteenth century impressed the general public with the mysterious powers of electric and magnetic fields, and therapeutic magnets had a rebirth, with many "doctors" promoting magnets to relieve pain, enhance sleep, and cure a wide variety of diseases. The most notable of these was Dr. C. J. Thacher, whom Collier's Magazine dubbed "King of the magnetic quacks" (Macklis 1993). His 1886 mail-order catalogue offered a variety of magnetic garments, and a complete costume contained more than 700 magnets, which provided "full and complete protection of all the vital organs of the body."
In the twentieth century, materials
scientists and engineers have developed stronger and stronger permanent magnets
-- alnico magnets in the 1930s, ferrite (ceramic) magnets in the 1950s, and
rare-earth magnets in the 1970s and 1980s. The latest rare-earth magnets,
neodymium-iron-boron, are more than a hundred times more powerful than the steel
magnets available in the last century to Edison, Bell, and C. J. Thacher
(Livingston 1996). Both ferrite magnets and the latest "neo" magnets
have had a tremendous impact on modern technology, but they have also
restimulated interest in the use of permanent magnets for magnetic therapy. Most
magnetic therapy products today, like most refrigerator magnets, contain
inexpensive ferrite magnets, but many suppliers offer neodymium "supermagnets"
in their top-of-the-line products.
Both
ferrite and rare-earth magnets, unlike earlier magnetic materials such as steels
and alnicos, have great resistance to demagnetization, allowing thin disks to be
magnetized. (Earlier magnets had to be long and thin to avoid being demagnetized
by the internal fields produced by the poles at the ends.) This feature allows
modern magnets to be mounted in a variety of thin products that can be applied
to the body with the magnetic field emanating from the surface.
Some suppliers recommend applying
magnetic patches directly to your aches and pains, while others recommend
applying small Band-Aid-like patches to acupuncture points. Magnetic belts
containing sixteen or more magnets are purported to ease back pain, and similar
magnetic wraps are offered for almost any part of the body, including hands,
wrists, elbows, knees, ankles, and feet (magnetic insoles are particularly
popular). For headaches you can wear magnetic headbands, magnetic earrings, or
magnetic necklaces. (One company marketing magnetic necklaces provides simple
instructions: the necklace should be put on as soon as the headache appears and
removed as soon as it goes away. Since most headaches come and go, following
these instructions precisely will clearly produce persuasive evidence of the
necklace's efficacy.)
Many magnetic necklaces, bracelets,
and earrings are formed from silver- and gold-rich magnetic alloys and promoted
as both fashionable and therapeutic. One catalog claims magnetic earrings
"stimulate nerve endings that are associated with head and neck pain,"
and magnetic bracelets "act upon the body's energy field" and
"correct energy imbalances brought by electro-magnetic contamination or
atmospheric changes." Larger items include magnetic seat cushions, magnetic
pillows, and magnetic mattress pads, the last claiming to produce an
"energizing sleep field." One supplier offers a PCD -- Prostate
Comfort Device for older men. If properly placed while you sit watching
television or driving your car, you will no longer have to get out of bed
several times a night to relieve yourself!
To avoid trouble with the Food and
Drug Administration, most suppliers emphasize only "comfort" and
usually specifically state "no medical claims are made." Some,
however, are far less careful. One company in Kansas markets a book entitled Curing
Cancer With Supermagnets. The authors of the book claim to have cured
cancer simply by hanging a neodymium "supermagnet" around the
patient's neck. The cancer discussed in the advertisement was a breast cancer,
but they report that "the supermagnets influence the whole body" and
"our method can cure all types of cancer."
Many magnetic therapy products have
alternating arrays of north and south poles facing the patient. Some have
detailed explanations of why a circular pattern of poles is optimal, while
others offer poles in checkerboard or triangular patterns. Nikken, the
Japan-based firm that has used a multilevel marketing scheme to expand from an
annual business in the U. S. of $3 million in 1989 to $150 million today,
primarily offers products with alternating poles.
One clear difference between such multipolar magnetic devices and unipolar devices (with only one pole facing the patient) is the "reach" of the magnetic field. The field from even unipolar magnets decreases very rapidly with increasing distance from the magnet, but the field from multipolar magnets decreases much more rapidly. If multipolar magnets really have any effects on the human body, they will be limited to depths of penetration of only a few millimeters. (Many refrigerator magnets are multipolar, which limits the thickness of paper they can hold to the refrigerator, but also limits the damage they can do to nearby credit and ATM cards.)
Other suppliers offer only unipolar
magnets, and some emphasize the importance of having only south-seeking poles
facing the body. Contrary to common scientific usage, they call south-seeking
poles north poles. Since opposite poles attract, they argue that a pole that
seeks south must be a north pole. (Here practitioners of magnetic therapy are
perhaps more logical than mainstream science, which calls the south-seeking pole
a south pole, requiring that the earth's magnetic pole in Antarctica is, by the
standard scientific terminology, a north pole.) Dr. Buryl Payne, in his book The
Body Magnetic (1988), argues that south-seeking poles calm tissue but
north-seeking poles stimulate tissue, and you should therefore never expose
tumors or infections to north-seeking poles. When I suggested to one
practitioner that different effects from different poles seemed to violate basic
rules of symmetry, he assured me that the rules were reversed in the southern
hemisphere.
One of the most ardent advocates of
magnetic therapy is Dr. William Philpott of Oklahoma, who publishes his own Magnetic
Energy Quarterly. He is also on the board of the Bio-Electro-Magnetics
Institute of Reno, Nevada, a nonprofit "research and educational
organization" and an advisor to the NIH Office of Alternative Medicine. His
wife happens to have a business selling "Polar Power Magnets." Dr.
Ronald Lawrence of California is President of the North American Academy of
Magnetic Therapy and reports that he has successfully used magnets to relieve
pain in hundreds of his patients. He is associated with Magnetherapy, a Florida
company that markets "Tectonic Magnets." Both Dr. Philpott and Dr.
Lawrence favor unipolar magnets.
The efficacy of magnetic therapy (or
of any other medical treatment, mainstream or alternative) does not depend on
our understanding the biological mechanism. Nevertheless most promoters of
magnetic therapy recognize the need for offering some plausible explanation. The
mechanism most commonly offered for various therapeutic effects of magnets is
improved blood circulation, despite a lack of clear evidence for such an effect.
Other suggestions include alteration of nerve impulses, increased oxygen content
and increased alkalinity of bodily fluids, magnetic forces on moving ions, and
decreased deposits on the walls of blood vessels.
The broadest explanation was
presented by Dr. Kyochi Nakagawa of Japan, who claims that many of our modern
ills result from "Magnetic Field Deficiency Syndrome." The earth's
magnetic field is known to have decreased about 6 percent since 1830, and
indirect evidence suggests that it may have decreased as much as 30 percent over
the last millennium. He argues that magnetic therapy simply provides some of the
magnetic field that the earth has lost.
Magnetic therapy is also prominent in
the treatment of thoroughbred racehorses. An injured racehorse represents
potential loss of a substantial investment, providing considerable incentive to
try "alternative medicine" to supplement mainstream veterinary
treatment. Magnetic pads for a variety of leg problems, magnetic blankets,
magnetic hoof pads, etc., all get ringing endorsements from many horse trainers
-- and even some veterinarians. One marketer of magnetic products for human’s
reports that he first became convinced of their effectiveness when he used them
on his ailing llama! Enthusiasts argue that the placebo effect could not be
effective on horses or other animals, but forget that it may influence the human
who is interpreting the effect of magnetic therapy on the animal.
These
examples and the centuries-old connection between magnets and quackery, have led
many to consider modern magnetic therapy as total hokum, with the many
testimonials for the success of magnetic treatments explainable by placebo
effects. But the Baylor study, seemingly a careful double-blind study, has
surprised many.
The study was conducted by Dr. Carlos Vallbona on fifty post-polio patients at Baylor's Institute for Rehabilitation Research in Houston. Bioflex, Inc., of Corpus Christi provided both the magnets (multipolar, circular pattern) and a set of visually identical sham magnets to serve as controls. To keep the study "double-blind" neither the patients nor the staff were informed as to which devices were active magnets, and which were shams. Before and after the forty-five-minute period of magnet therapy, the patients were asked to grade their pain on a scale from 0 to 10. The twenty nine patients with active magnets reported, on average, a significant reduction of pain (from 9.6 to 4.4), while the twenty-one patients with shams reported a much smaller average reduction (from 9.5 to 8.4). This is a substantial difference, and if the double-blind study was successfully conducted, cannot be explained by a placebo effect.
For a hardened skeptic, some doubts
remain. Both Dr. Vallbona and his colleague, Dr. Carlton Hazlewood, had reported
the successful personal use of magnets to relieve their own knee pains prior to
the study, raising doubts as to their objectivity.
Conscious or unconscious biases of
researchers can have very subtle and unrecognized effects on the results of
their studies, and a serious difficulty of conducting any double-blind studies
with magnets is the ease of distinguishing active magnets from sham magnets
(although the patients were reportedly observed during the therapy period to
assure that they were not surreptitiously testing their magnets). Another
difficulty of any studies of pain relief is the highly subjective nature of the
data.
Despite these various reasons for caution, the results of this study have altered the views of many physicians. Dr. William Jarvis, president of the National Council Against Health Fraud, had formerly dismissed magnet therapy as "essentially quackery." He now tentatively admits that it may have value for post-polio pain.
More studies will be needed before
magnetic therapy will be accepted by a majority of the medical community, and
some studies are already underway. Last year the NIH Office of Alternative
Medicine gave a million-dollar grant to Dr. Ann Gill Taylor of the School of
Nursing of the University of Virginia to study the use of magnets to relieve
pain. Among other things, she will be testing the effectiveness of magnetic
sleep pads in relieving pain in patients suffering from fibromyalgia, a common
disease involving joint and muscle pain. While we wait for the results of these
and other studies, does what we know about magnetic fields and the human body,
make it plausible that magnetic therapy for pain might have a physical basis
beyond mind/body effects?
The
electrochemical processes of the human body are extremely complex and
incompletely understood, and physical effects of magnetic fields cannot be ruled
out. Many thousands of papers have in fact been published on biological effects
of electromagnetic fields, much of it focused on the effects of radio-frequency
and microwave fields or, in recent years, on fields at power-line frequencies
(fifty or sixty cycles per second). Studies of biological effects of steady
magnetic fields (reviewed by Frankel and Liburdy 1996) have concentrated mostly
on high fields of the level encountered in MRI magnets, typically of the order
of 10,000 gauss (1 tesla). Unfortunately, research has been very limited at
field levels typical of magnetic therapy products, most of which are limited to
a few hundred gauss, even at the magnet surface. (The earth's field is a bit
less than half a gauss.)
Viewed simply as inert material, the
human body, like its primary constituent, water, is diamagnetic, i.e., weakly
repelled by magnetic fields. In response to an applied magnetic field, the
electrons in water molecules make slight adjustments in their motions, producing
a net magnetic field in the opposing direction about 100,000 times smaller than
the applied field. With the removal of the applied field, the electrons return
to their original orbits, and the water molecules once again become nonmagnetic.
(We perhaps should note that some promoters of magnetic therapy also promote
"magnetized water." You can't magnetize water. Although water responds
weakly to an applied field, the response disappears as soon as the field is
removed.) Although the diamagnetism of water and most living things is very
weak, a high-field electromagnet producing 160,000 gauss (16 tesla) at the
center of the coil has recently been used to levitate not only water drops but
also flowers, grasshoppers, and small frogs (Berry and Geim 1997), the
"flying frogs" drawing worldwide media coverage. Since fields of that
magnitude are required to balance gravitational forces, the much lower fields of
magnetic-therapy devices can only produce diamagnetic forces that are thousands
of times smaller than gravity. (The repulsive force will be proportional to the
product of the field and the field gradient.)
Some dubious literature suggests that
magnetic fields attract blood, citing all the iron it contains. However, iron in
the blood is very different from metallic iron, which is strongly magnetic
because the individual atomic magnets are strongly coupled together by the
phenomenon we call ferromagnetism. The remarkable properties of ferromagnetic
materials are a result of the cooperative behavior of many, many magnetic atoms
acting in unison. The iron in blood consists instead of isolated iron atoms
within large hemoglobin molecules, located inside the red blood cells. Although
each of the iron atoms is magnetic, it is not near other iron atoms, and remains
magnetically independent.
The net effect of the weak
paramagnetism of the isolated iron atoms in hemoglobin is only a slight decrease
in the overall diamagnetism of blood. Blood, like water, is weakly repelled by
magnetic fields, not attracted.
Although most components of the human
body and other living things are weakly diamagnetic, many organisms have been
shown to contain small amounts of strongly magnetic materials, usually magnetite
(Fe3O4). The most extreme case is that of magnetotactic bacteria, originally
found in mud collected from the marshes of Cape Cod. Each contains a long chain
of magnetite particles that interact strongly enough with the earth's magnetic
field to orient the bacteria along the field. Magnetite crystals have also been
found in pigeons, honeybees, many mammals, and even in the human brain, but in
proportionately much smaller amounts than in the bacteria. It seems very
unlikely that there is enough magnetite within the human body to provide a
possible mechanism to explain magnetic therapy. However, if magnetite particles
were located at strategic places, they could locally amplify the effects of low
magnetic fields and, for example, modify ion flow across cell membranes, of the
type involved with electrical transmission in nerve cells.
More likely mechanisms are those
based on magnetic forces on moving charged particles, possibly including ions or
charged molecules in flowing blood, moving across cell membranes, moving across
synapses between nerve cells, etc., or those based on more subtle effects on
biochemical reactions (Frankel and Liburdy 1996). Although no physical
mechanisms for magnetic therapy have been established, the possibilities are
numerous and complex. Only further clinical tests, carefully controlled to
account for placebo effects, can confirm or dispute the results of the Baylor
study and prove or disprove the claims of magnetic therapy.
Some media reports have not
sufficiently distinguished the Baylor form of magnetic therapy, based on modest
static fields from permanent magnets, with a more accepted form of
"magnetic therapy" based on high pulsed magnetic fields from
electromagnets (Malmivuo and Plonsey 1995). Pulsed magnetic fields are very
different from static magnetic fields, because, via Maxwell's equations,
time-varying magnetic fields induce electric fields. Electric fields have
pronounced biological effects, particularly on nerve and muscle cells, as we
have known since the days of Galvani and his twitching frogs' legs. Many years
ago the FDA approved the use of pulsed magnetic fields in "bone growth
stimulators" for the treatment of fractures that were slow to heal, and
research on "magnetic stimulation" -- pulsed magnetic fields applied
to the brain or other components of the nervous system -- has grown rapidly in
recent years. Transcranial magnetic stimulation, in which the patient receives
hundreds of magnetic field pulses of 1 tesla or more, each only a millisecond in
duration, has shown considerable promise as a means of treating depression.
However, these forms of pulsed-field magnetic therapy are based on biological
effects of induced electric fields, and are very different from the use of the
static fields from permanent magnets.
Claims
of therapeutic effects of permanent magnets should still be regarded with
considerable skepticism. Most of the many testimonials to the effectiveness of
magnetic therapy devices can be attributed to placebo effects and to other
effects accompanying their use. For example, 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 aging
athletes that they are no longer young and should not overexert their muscles.
All these effects are helpful with or without magnets. One British study of
pulsed-field bone-growth stimulators, which were approved decades ago by the FDA,
found that they were equally successful when the devices were not activated
(Barker 1984), and concluded that their effectiveness resulted from the enforced
inactivity associated with their use, rather than from the pulsed magnetic
fields.
The more extreme claims of magnetic therapy, such as curing cancer by hanging supermagnets around your neck, are not only nonsense but also dangerous, since they may divert patients from seeking appropriate treatment from mainstream medicine. Magnetic jewelry and most other magnetic-therapy products probably are harmless beyond a waste of money. Several years ago, a double-blind study found that magnetic necklaces produced no relief of neck or shoulder pain (Hong 1982).
The results of the Baylor study,
however, raise the possibility that at least in some cases, topical application
of permanent magnets may indeed be useful in pain relief, a conclusion that
should be regarded as tentative until supported by further studies. Any
mechanism for such an effect remains mysterious, but an effect of static
magnetic fields on the complex electrochemical processes of the human body is
not impossible. My own guess is that inexpensive refrigerator magnets are as
likely to provide help as the more expensive magnets marketed specifically for
therapy. (But since human nature leads us to expect more from more expensive
items, use of refrigerator magnets will probably decrease the placebo effect!)
Barker,
A. T. et al. 1984. Pulsed magnetic field therapy for tibial non-union. Lancet
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Buranelli,
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Frankel,
Richard B. and Robert P. Liburdy. 1996. Biological effects of static magnetic
fields (in Handbook of Biological Effects of Electromagnetic Fields, second
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C. Z. et al. 1982. Magnetic necklace: Its therapeutic effectiveness on neck and
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Livingston,
James D. 1996. Driving Force: The Natural Magic of Magnets. Harvard University
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Roger M. 1993. Magnetic healing, quackery, and the debate about the health
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Malmivuo,
Jaakko and Robert Plonsey. 1995. Bioelectromagnetism: Principles and
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Buryl. 1988. The Body Magnetic (self-published).
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Carlos, Carlton F. Hazlewood, and Gabor Jurida. 1997. Response of pain to static
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Copyright © 1999 Active Health. All rights reserved.
Revised: January 29, 2008
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