Published in Between Heaven and Earth: An Introduction to Integrative Approaches to Health Care (2nd Edition), a publication ofAmerican Medical Student Association Scarfed from http://www.amsa.org/pdf/heavenearth.pdf and reprinted here without permission under the Fair Use Doctrine. Copyright © 1999, American Medical Student Association.
Standing Committee on Medical Education
National Project on Alternative and Complementary MedicinePlease see Magnetic Therapy Current Evidence Review
Cleopatra, wishing to prevent aging, reportedly wore a lodestone (natural magnetic rock) on her forehead while she slept. In addition to the ancient Egyptians, ancient Chinese, Greek and Indian cultures used magnets for therapeutic purposes. The word magnet was first coined by the Greeks. In fact, the first person in recorded history to discuss the therapeutic benefits of magnetism is believed to be Aristotle. Two famous German scientists, Paracelsus (15th century), and later, Mesmer (18th century), studied magnetic therapy. Both men controversially, yet successfully, introduced this form of healing to the public.
The popularity of magnet therapy in the United States began to rise during the 1800s and soared in the post-Civil War era. Sears-Roebuck advertised magnetic jewelry in its catalog for the healing of virtually any ailment. An Austrian psychoanalyst by the name of Wilhelm Reich emigrated to the United States in 1939 and researched the effects of electromagnetism on humans. (Interestingly, Reich, a former student of Sigmund Freud, died in prison after ignoring an FDA order to cease his movement against nuclear pollution.) Today, Germany, Japan, Israel, Russia and at least 45 other countries considers magnetic therapy to be an official medical procedure for the treatment of numerous ailments, including various inflammatory and neurological problems.
The medical definition of a magnetic north pole is the pole which attracts the arrowhead of a compass. When one uses a gauss meter, the meter arrow will move toward the negative sign when overlying the north pole, which is therefore also designated as the "negative" pole.
There are generally two different methods of magnetotherapy in use as this time. The first involves exposure to only the north pole with high gauss strength (2000-4000). The second and more widely-used and accepted method involves the use of low gauss strength during simultaneous exposure to both north and south poles. The latter bipolar method often employs thin, flexible magnetic pads that may be directly applied to an area of the body in a bandage-like fasion. Treatment duration depends on the persistence of symptoms. Some suggest continual application (24 hours a day) until symptoms are relieved. For this reason, the current trend is to market magnetics that are as unobtrusive and comfortable as possible.
The exact reason for the therapeutic effects of magnetic therapy is currently unknown. However, several theories have been suggested. Some believe that the exclusive use of negative (north) polarity promotes alkalinity in the body and therefore helps to maintain the body's normal pH of 7.4 (and normal metabolic function) in the face of acute, maladaptive responses (immunologic, non-immunologic or degenerative condition) which may promote acidernia.
The principle of the bipolar magnetic effect, on the other hand, involves a completely different theory based on the Hall Effect. Upon exposure to a magnetic field, charged particles moving within a wire are deflected from a straight path down the wire depending on the orientation of the field vector. In humans, blood is thought to be an electrical conductor. Flow of electrolytes forms a current throughout the body within the bloodstream. When these ions pass under a magnet, separation occurs based on charge: positive ions move towards the negative (north) pole while negative ions move towards the positive pole. Ions thus deflected encounter and push against the vessel wall, creating some amount of vessel expansion. Vasodilatation results in increased delivery of oxygen and nutrients to the damaged cells, as well as enhanced removal of metabolic byproducts and toxins. Reports indicate that static bipolar magnets help blood vessels expand through this natural effect on charged particles in the blood. Small vessels are reportedly widened as the ions crisscross back and forth between north and south poles of the magnet. Small "eddy currents" also occur in the bloodstream due to the ion separation. These currents, similar to those found in a river, widen the vessel diameter just as eddy currents in a river push the banks outward. Additionally, histamine and prostaglandins, compounds believed to stimulate the pain-spasm cycle, may be removed from the area by this increased blood flow, thereby interrupting the pain cycle.
A second theory for the effectiveness of bipolar magnetic therapy has been championed by Vincent Ardizonne, who designed the "checkerboard pattern" of bipolar magnets (see below). He suggested that bipolar magnets are able to alter the ionic balance of the pain neuron. After a pain neuron has been chronically stimulated, it may develop a resting membrane potential about the usual -70 mV (for instance, around 60 mV). Subsequently, it is easier to surpass the "firing threshold" (around -50 mV), depolarize the neuron and send the painful stimulus to the brain. Ardizonne's theory suggests that the ionic (voltage) pattern created as a result of the magnetic field/Hall Effect helps reestablish the proper resting membrane potential of the axon fiber.
Not all magnets are created equal. The design and strength of the magnet are key factors in maximizing therapy. While the magnetic field of the earth is less than 10 gauss, magnets sold for therapeutic purposes generally range from 300 to 500 gauss. Magnetic resonance imaging (MRI), for comparison, introduces a strong magnetic field in excess of 10,000 gauss. Two magnets with identical strength may perform differently depending on their design. Standard magnets are reported to be maximally effective when blood passes through vessels directly perpendicular to a line connecting the north and south poles, as opposed to blood vessels that pass at an angle or parallelto the magnetic poles. This promotes the sideways deflection of ions and the subsequent vasodilatation described earlier. Consequently, one reportedly effective magnetic design uses concentric circles of alternating polarity. The concentric design supposedly allows maximal pentetration to the capillaries' orientation. According to one expert on concentric magnets, Jack Scott, Ph.D., "Magnets applied to muscles after a hard workout should increase blood flow and speed recovery." Dr. Scott has been an adviser to the U.S. Track and Field team for the past four Olympic Games.
Researchers at Baylor University Medical Center recently conducted a double-blind study on the use of concentric-circle magnets to relieve chronic pain in 50 post-polio patients. Active as well as placebo magnets ranging from 300-500 gauss were placed on the affected area of each patient for 45 minutes. A significant number of patients (76 percent) reported less pain when using the active magnets as opposed to those who reported less pain while using a placebo magnet (19 percent).
It has been suggested that magnets may be used at any time during sports training and in recovery from injury. However, exceptions to this rule have been noted in the time period immediately following an injury. Sports-medicine physicians suggest using ice to reduce the swelling through restriction of blood flow. Once swelling is under control, magnets may be used to bring more blood to an area for faster healing. Magnetic application to an acute injury less than 24 hours old that involves bleeding is not recommended because the clotting process may be delayed. Finally, pregnant women are advised against using magnetic therapy.
Not all forms of magnetism are free of side effects. For reasons not yet understood, the AC electromagnetic field from a power line is potentially harmful, wheeas the pure DC magnetic field from a solid state magnet is possiby therapeutic. There is controversial evidence of negative effects, including cancer, stemming from high=-power, pulsating magnetic pollution and high-power transmission lines. However, it is again important to keep in mind the difference between electromagnetic fields and pure magnetic fields.
Another risk that is worth mentioning involves the ingestion of small magnets by children. Bowel walls fistulate between the steady magnetic attraction between two or more beads. Erosion and perforation of the bowel wall may also occur. A report in the Journal of Pediatric Surgery describes a three-year-old girl who swallowed multiple magnetic beads taken from her parent's therapeutic necklace. It took less than two weeks to develop a fistula between the stomach and jejunum.
Although there are countless testimonials in fitness magazines, internet sites and various books vouching for the effectiveness of this age-old form of alternative therapy, there is a profound lack of overall proof of the legitimacy of magnetic therapy in peer-reviewed medical literature. A recent note in the Mayo Clinic Health Letter acknowledges this incongruity: "While research may someday find magnetic therapy beneficial, to date there's little medical evidence to back up health claims, and the therapy is still considered experimental."
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