Magnet Therapy: A Skeptical View
Stephen Barrett, M.D.
Magnetic devices are claimed to relieve pain and to have therapeutic value against a large number of diseases and conditions. The way to evaluate such claims is to ask whether scientific studies have been published. Pulsed electromagnetic fields—which induce measurable electric fields —have been demonstrated effective for treating slow-healing fractures and have shown promise for a few other conditions. Relatively few studies have been published on the effect on pain of small, static magnets marketed to consumers . Explanations that magnetic fields "increase circulation," "reduce inflammation," or "speed recovery from injuries" are simplistic and are not supported by the weight of experimental evidence .
The main basis for pain-reduction claims studies are two double-blind studies, one conducted at Baylor College of Medicine in Houston, which dealt with knee pain, and the other conducted at 27 sites, which tested the effects on diabetic neuropathy, a degenerative condition that produces pain and burning of the feet. Both of these studies had significant flaws in their design. Better studies have found no significant benefit.
The Baylor study compared the effects of magnets and sham magnets on knee pain. The study involved 50 adult patients with pain related to having been infected with the polio virus when they were children. A static magnetic device or a placebo device was applied to the patient's skin for 45 minutes. The patients were asked to rate how much pain they experienced when a "trigger point was touched." The researchers reported that the 29 patients exposed to the magnetic device achieved lower pain scores than did the 21 who were exposed to the placebo device [3} This study provides no legitimate basis for concluding that magnets offer any health-related benefit:
- Although the groups were said to be selected randomly, the ratio of women to men in the experimental group was twice that of the control group. If women happen to be more responsive to placebos than men, a surplus of women in the "treatment" group would tend to improve that group's score.
- The age of the placebo group was four years higher than that of the control group. If advanced age makes a person more difficult to treat, the "treatment" group would again have a scoring advantage.
- The investigators did not measure the exact pressure exerted by the blunt object at the trigger point before and after the study.
- Even if the above considerations have no significance, the study should not be extrapolated to suggest that other types of pain can be relieved by magnets.
- There was just one brief exposure and no systematic follow-up of patients. Thus there was no way to tell whether any improvement would be more than temporary.
- The authors themselves acknowledged that the study was a "pilot study." Pilot studies are done to determine whether it makes sense to invest in a larger more definitive study. They never provide a legitimate basis for marketing any product as effective against any symptom or health problem.
The multicenter study, headed by Michael Weintraub, M.D., of New York Medical College, involved 48 investigators in 27 states. Of 375 subjects with diabetic neuropathy who were randomly assigned to wear magnetized insoles or placebo (nonmagnetic) devices for 4 months, 259 completed the study. The authors concluded that there were statistically significant reductions during the third and fourth months in burning; numbness and tingling; and exercise-induced foot pain . However, they noted that despite statistical improvement in pain and quality-of-life scores, there was only "modest clinical benefit." There are also good reasons to challenge the statistical analysis that underlies their conclusions:
- The main outcome table listed 4 sets of average group measurements taken at one-month intervals, which produced 20 possible endpoints.
- Symptom severity in both treatment and placebo groups gradually lessen, but there is little month-to-month variation.
- At each endpoint, the average results in both looked similar, but the standard deviations were large. By breaking the data into subgroups, the authors were able to declare that certain ones were significant. However, with many endpoints and widely scattered data, differences between some endpoints are likely to occur by chance alone. The most favorable differences can then be chosen to suggest significance when none exists.
At least three well-designed pain studies have been negative:
- Researchers at the New York College of Podiatric Medicine have reported negative results in a study of patients with heel pain. Over a 4-week period, 19 patients wore a molded insole containing a magnetic foil, while 15 patients wore the same type of insole with no magnetic foil. In both groups, 60% reported improvement, which suggested that the magnetic foil conveyed no benefit .
- Researchers at the VA Medical Center in Prescott, Arizona conducted a randomized, double-blind, placebo-controlled, crossover study involving 20 patients with chronic back pain. Each patient was exposed to real and sham bipolar permanent magnets during alternate weeks, for 6 hours per day, 3 days per week for a week, with a 1-week period between the treatment weeks. No difference in pain or mobility was found between the treatment and sham-treatment periods .
- Researchers at the Mayo Clinic compared the effects of wearing magnetic or sham-magnetic cushioned insoles over an 8-week period by 101 people with heel pain and found no difference between the treatment and control groups .
Magnets have also been claimed to increase circulation. This claim is false. If it were true, placing a magnet on the skin would make the area under the magnet become red, which it does not. Moreover, a well-designed study that actually measured blood flow has found no increase. The study involved 12 healthy volunteers who were exposed to either a 1000-gauss magnetic disk or an identically appearing disk that was not magnetic. No change in the amount or speed of blood flow was observed when either disk was applied to their arm. . The magnets were manufactured by Magnetherapy, Inc, of Riviera Beach, Florida, a company that has been subjected to two regulatory actions.
Legal and Regulatory Actions
In 1998, Magnetherapy, Inc., signed an Assurance of Voluntary Compliance with the State of Texas to pay a $30,000 penalty and to stop claiming that wearing its magnetic device near areas of pain and inflammation will relieve pain due to arthritis, migraine headaches, sciatica or heel spurs. The agreement also requires Magnetherapy to stop making claims that its magnets can cure, treat, or mitigate any disease or can affect any change in the human body, unless its devices are FDA-approved for those purposes . Ads for the company's Tectonic Magnets had featured testimonials from athletes, including golfers from the senior pro tours. Various ads had claimed that Tectonic Magnets would provide symptomatic relief from certain painful conditions and could restore range of motion to muscles and joints. The company had provided retailers with display packages that included health claims, written testimonials, and posters of sports stars. Texas Attorney General Dan Morales stated that some claims were false or unsubstantiated and others had rendered the product unapproved medical devices under Texas law. In 1997, the FDA had warned Magnetherapy to stop claiming that its products would relieve arthritis; tennis elbow; low back pain; sciatica; migraine headache; muscle soreness; neck, knee, ankle, and shoulder pain; heel spurs; bunions; arthritic fingers and toes; and could reduce pain and inflammation in the affected areas by increasing blood and oxygen flow .
In 1999, the FTC obtained a consent agreement barring two companies from making unsubstantiated claims about their magnetic products. Magnetic Therapeutic Technologies, of Irving, Texas, is barred from claiming that its magnetic sleep pads or other products: (a) are effective against cancers, diabetic ulcers, arthritis, degenerative joint conditions, or high blood pressure; (b) could stabilize or increase the T-cell count of HIV patients; (c) could reduce muscle spasms in persons with multiple sclerosis; (d) could reduce nerve spasms associated with diabetic neuropathy; (e) could increase bone density, immunity, or circulation; or (f) are comparable or superior to prescription pain medicine. Pain Stops Here! Inc., of Baiting Hollow, N.Y., may no longer claim that its "magnetized water" or other products are useful against cancer, diseases of the liver or other internal organs, gallstones, kidney stones, urinary infection, gastric ulcers, dysentery, diarrhea, skin ulcers, bed sores, arthritis, bursitis, tendinitis, sprains, strains, sciatica, heart disease, circulatory disease, arthritis, auto-immune illness, neuro-degenerative disease, and allergies, and could stimulate the growth of plants.
On August 8, 2000, the Consumer Justice Center, of Laguna Niguel, California filed suit in Orange County Superior Court charging that Florsheim and a local shoe store (Shoe Emporium) made false and fraudulent claims that their MagneForce shoes (a) correct "magnetic deficiency," (b) "generate a deep-penetrating magnetic field which increases blood circulation; reduces leg and back fatigue; and provides natural pain relief and improved energy level."; and (c) their claims are established and proven by scientific studies . A few days after this suit was filed, Florsheim removed the disputed ad from its Web site.
In 2001, Richard Markoll, his wife Ernestine, David H. Trock, M.D., and Bio-Magnetic Treatment Systems (BMTS) pled guilty to criminal charges in connection with a scheme involving pulsed magnetic therapy. The participants used fraudulent billing codes to seek payment from Medicare and three other insurance plans for treatment with a device (Electro-Magnetic Induction Treatment System, Model 30/30) that lacked FDA approval . The treatments—called pulsed signal therapy (PST)—were administered in a clinical trial on an investigational basis not approved by the FDA. The Markolls were sentenced to 3 years probation, a $4,000 fine and a $100 special assessment. Ernestine Markoll was sentenced to 2 years probation, a $1,000 fine and a $25 special assessment. Magnetic Therapy, was sentenced to a 1-day summary probation and a $200 special assessment. The Markolls also signed a civil settlement under which they agreed to pay the U.S Government $4 million . The device was invented by Richard Markoll, MD, PhD, who does not have a medical license but is described in Web site biographies as a graduate of Grace University School of Medicine, a Caribbean medical school. Trock, a former principal investigator for Magnetic Therapy Center, PC, Danbury, CT, was sentenced to 6 months probation. and ordered to make restitution of $35,250 . Trock has co-authored studies claiming that PST is effective for treating pain, but the device is not FDA-approved for that purpose.
In September 2002, California Attorney General Bill Lockyer charged Florida-based European Health Concepts, Inc. (EHC) with making false and misleading claims about its magnetic mattress pads and seat cushions. The complaint, filed in Sacramento Superior Court, also named EHC president Kevin Todd and several sales managers and agents as defendants. The suit seeks more than $1 million in civil penalties for engaging in unfair business practices and making false claims; $500,000 in civil penalties for transactions involving senior citizens; and full restitution for purchasers of the products. The complaint alleged that prospective customers, primarily senior citizens, were invited to attend a free dinner seminar at which they were told that EHC's products could help people suffering from fibromyalgia, lupus, sciatica, herniated discs, asthma, bronchitis, cataracts, chronic fatigue syndrome, colitis, diverticulitis, heart disease, multiple sclerosis, and more than 50 other health conditions. The sales agents offered phony price discounts for immediate purchases that actually were the company's regular prices. .
A recent press report indicates that Thorsten Wietschel, who markets magnetic matresses through local gatherings, had two brushes with the law in the United States and is now pitching them in Canada. The report states that (a) was charged with grand theft in California but not prosecuted because he left the state, and (b) a civil action in Arizona resulted in a court order to repay $150,000 to buyers and pay $2 million in penalties .
The Bottom Line
There is no scientific basis to conclude that small, static magnets can relieve pain or influence the course of any disease. In fact, many of today's products produce no significant magnetic field at or beneath the skin's surface.
- Livingston JD. Magnetic therapy: Plausible attraction. Skeptical Inquirer 25-30, 58, 1998.
- Ramey DW. Magnetic and electromagnetic therapy. Scientific Review of Alternative Medicine 2(1):13-19, 1998.
- Vallbona C, Hazelwood CF, Jurida G. Response of pain to static magnetic fields in postpolio patients: A double-blind pilot study. Archives of Physical and Rehabilitative Medicine 78:1200-1203, 1997.
- Weintraub MI. Static magnetic field therapy for symptomatic diabetic neuropathy: a randomized, double-blind, placebo-controlled trial. Archives of Physical Medicine and Rehabilitation 84:736-746, 2003.
- Caselli MA and others. Evaluation of magnetic foil and PPT Insoles in the treatment of heel pain. Journal of the American Podiatric Medical Association 87:11-16, 1997.
- Collacott EA and others. Bipolar permanent magnets for the treatment of chronic low back pain. JAMA 283:1322-1325, 2000.
- Winemiller MH and others. Effect of magnetic vs sham-magnetic insoles on plantar heel pain: a randomized controlled trial. JAMA 290:1474-1478, 2003.
- Mayrovitz HN and others. Assessment of the short-term effects of a permanent magnet on normal skin blood circulation via laser-Doppler flowmetry. Scientific Review of Alternative Medicine 6(1):9-12, 2002.
- Morales halts unproven claims for magnet therapy. News release, April 9, 1998.
- Gill LJ. Letter to William L. Roper, Feb 3, 1997.
- Jeff Wynton and the Consumer Justice Center v. Florsheim Group, Inc., Shoe Emporium. Superior Court of California, Orange County, Case #00CC09419, filed Aug 8, 2000.
- Burns EB. Omnibus ruling on defendants' motion to strike and motions to dismiss. United States of America v Richard Markoll, Ernestine Binder Markoll, and Bio-Magnetic Systems, Inc. U.S. District Court, District of Connecticut, No. 3:00cr133(EBB), Jan 2001.
- Defense Criminal Investigative Service press release, Aug, 2001.
- Defense Criminal Investigative Service press release, June, 2001.
- Barrett S. California Attorney General sues magnetic mattress pad sellers. Quackwatch, Sept 24, 2002.
- Caldwell B. 'Something doesn't seem right.' After running afoul of consumer laws in the U.S., Thorsten Wietschel has come north to sell magnetic mattress covers. The Record, Jan 26, 2008.
From David Gessell, a design engineer from Oakland, California:
I recently was introduced to the bizarre concept that magnetic insoles can promote health and relieve pain. The seller promised improved circulation, reduced pain, better oxygen uptake, weight loss, and more or less any other positive benefit that could be imagined or requested. The mechanism presented was: Humans evolved (or were created, for those residents of Kansas) in the presence of the Earth's magnetic fields. These fields are blocked by concrete and pavement and other human structures. In the supposed absence of these fields the body in some way suffers. A friend had purchased magnetic insoles at an approximate cost of $100. She returned them after I explained that:
- Magnetic fields are not blocked by concrete (unless it is steel-reinforced). Any place a compass works, the earth's magnetic fields are present.
- Blood is not magnetic. If it were, one's body would explode in an MRI machine.
- DC magnetic fields have no known effect at on the human body at levels strong enough to bend steel bars as commonly experienced by magnet and fusion researchers. These individuals are exposed to magnetic field strengths 6 to 10 orders of magnitude greater than that created by the rubberized magnetic insoles, without becoming either more or less healthful.