Magnetic Therapy: Plausible Attraction?
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?
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?
Early History
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 magnetizers 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 re stimulated
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.
Magnetic Therapy Today
Both ferrite and rare-earth magnets, unlike earlier magnetic materials
such as steels and alnico's, 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 humans 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?
Magnetic Fields and the Body
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.
Conclusions
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!)
References
* Barker, A. T. et al. 1984. Pulsed magnetic field therapy for tibial
non-union. Lancet 994-996.
* Berry, M. V. and A. K. Geim. 1997. Of flying frogs and levitrons. Eur.
J. Phys. 18: 307-313.
* Buranelli, V. 1975. The Wizard from Vienna. Coward, McCann & Geoghegan.
* Frankel, Richard B. and Robert P. Liburdy. 1996. Biological effects
of static magnetic fields (in Handbook of Biological Effects of Electromagnetic
Fields, second edition, Charles Polk and Elliot Postow, eds. CRC Press).
* Hong, C. Z. et al. 1982. Magnetic necklace: Its therapeutic effectiveness
on neck and shoulder pain. Archives of Physical Medicine and Rehabilitation
63:162-164.
* Livingston, James D. 1996. Driving Force: The Natural Magic of Magnets.
Harvard University Press.
* Mackay, Charles. [1841] 1932. Extraordinary Popular Delusions and the
Madness of Crowds. Reprint, L. C. Page.
* Macklis, Roger M. 1993. Magnetic healing, quackery, and the debate about
the health effects of electromagnetic fields. Annals of Internal Medicine
118(5): 376-383.
* Malmivuo, Jaakko and Robert Plonsey. 1995. Bioelectromagnetism: Principles
and applications of bioelectric and biomagnetic fields. Oxford University
Press.
* Payne, Buryl. 1988. The Body Magnetic (self-published).
* Vallbona, Carlos, Carlton F. Hazlewood, and Gabor Jurida. 1997. Response
of pain to static magnetic fields in postpolio patients: A double-blind
pilot study. Archives of Physical and Rehabilitation Medicine 78(11):
1200-1203.
About the Author
James D. Livingston now teaches in the Department of Materials Science
and Engineering at the Massachusetts Institute of Technology, and was
for more than thirty years a physicist at General Electric's Corporate
Research and Development Center. He is the author of Driving Force: The
Natural Magic of Magnets (Harvard, 1996), a popular-science book on the
history, legends, science, and technology of magnets.
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