In this issue of Anesthesia & Analgesia, Cepeda et al. (1) present the results of a well-designed, randomized, double-blind trial showing that magnets fail to decrease pain in postoperative patients. At first glance, the reader might be tempted to dismiss the results as a boring waste of valuable time. Why should a journal even bother to publish a study if the treatment under investigation does not work? The reason is that negative results are often as important as positive findings. This is one of those cases.
As described by Cepeda et al., magnet merchants have flooded the market with magnets of all shapes and prices. A Google search of “miracle magnet therapy” (without quotes) returned about 521,000 distinct Internet references. If the first 10 references are any indication, magnets are being hawked for all varieties of healing wonders. Google's sponsored links include promotions to “End Pain with Magnets,” and “Magnetic Therapy USA Made, as recommended by Kevin Trudeau,” (whose claims include a relationship between pH, health (2), and cancer (3) that will surprise many anesthesiologists, accustomed as they are to arterial blood gas analysis). The evidence offered on the Internet to support claims about magnets is typically based on testimonials from athletes and celebrities (4), associated with pictures of kindly men in white coats with “MD” emblazoned on the pocket (5). As documented by Cepeda et al., it is crystal clear that billions of dollars have already been spent on magnet therapy, or perhaps, wasted on magnet therapy. To be blunt, there is no proven benefit to magnet therapy (6).
Governmental agencies worldwide have done little to regulate the international magnet therapy industry. The Food and Drug Administration (FDA) has authority to regulate magnets only if specific medical claims are made. To quote the FDA's Center for Devices and Radiological health, “Magnets marketed with medical claims are considered to be medical devices because they are promoted to treat a medical condition or to affect the structure or function of the body … To date, the FDA has not cleared for marketing any magnets promoted for medical uses” (7). To skirt the requirements of the law, magnet promoters often make only the vaguest of claims. The FDA statement continues, “Significant claims that are likely to trigger regulatory action include, but are not limited to, treatment of cancer, Human Immunodeficiency Virus, Acquired Immune Deficiency Syndrome, asthma, arthritis, and rheumatism.” Sadly, it appears that pain therapy does not count as a significant claim to trigger FDA enforcement.
The National Institutes of Health (NIH) has weighed in on magnets for pain therapy. The National Center for Complementary and Alternative Medicine (NCCAM) is perhaps the most controversial division of the NIH. NCCAM bends over backwards to keep an open mind to all types of “alternative” therapy. Nevertheless, NCCAM concluded in their research report “Questions and Answers About Using Magnets to Treat Pain” (8) that “Scientific research so far does not firmly support a conclusion that magnets of any type can relieve pain. However, some people do experience some relief. Various theories have been proposed as to why, but none has been scientifically proven. Clinical trials in this area have produced conflicting results. Many concerns exist regarding the quality and rigor of the studies conducted to date, leading to a call for additional, higher-quality, and larger studies.”
The Cepeda et al. article is an exemplary answer to the NIH's call for higher-quality studies. Exactly what did Cepeda et al. do? They used an appropriate study design, including stratified randomization, concealment of allocation, and masking with sham devices. What did they find? Perhaps not surprisingly, when properly studied under controlled conditions, magnets had no effect whatsoever. Indeed, Figure 3 in the Cepeda et al. article is a veritable poster child of what “no effect” looks like in a clinical trial. How did they publish their findings? They submitted the findings to a peer-reviewed journal, where experts in pain management evaluated their clinical trial design, study power, outcome measurements, and statistical analysis, and found them acceptably rigorous by contemporary scientific standards.
Will this be the end of magnet therapy? Certainly not. Sellers of “healing magnets” tout their products with almost religious zeal. There are too many claims, to much hokum, for a scientific study to have much impact. For example, nothing in the Cepeda et al. study disproves the efficacy of magnets for blepharitis: “Apply N side of small magnets to closed eye lids. Wash with North pole water” (9). A convert to magnetic therapy might concede that this study demonstrates that magnets do not decrease postoperative incisional pain, but will claim that it says nothing about any other types of pain.
Though this is not an entirely vapid criticism, it places the burden of proof on the scientific community to disprove claims of magnet efficacy. It is like saying, “you have proved that magnets do not decrease incisional pain; now you must prove that they do not decrease leg pain, arm pain, head pain, neck pain, back pain, foot pain, stomach pain, joint pain, etc., etc.” This is incorrect. The burden of proof is on the claimant to show efficacy. The burden of proof is not on the rest of the scientific community to show lack of efficacy. Although the burden of proof was not on them, Cepeda et al. still tackled this question with a rigorous self-funded study. Of course, such studies are likely to be self-funded, as magnet mongers have little to gain from high-quality research.
Randomized clinical trials such as the study of Cepeda et al. are one way to deal with the outrageous claims of magnet purveyors. Another way is to go back to the basic sciences and investigate whether or not healing via magnets is possible, even theoretically. Surprisingly, the answer appears to be no. Almost all magnetic “healing” devices use “static” magnets like those used to attach Johnny's homework to your refrigerator door. When dealing with magnets, the word “static” means nonmoving. It has nothing to do with static electricity. Moving magnets can create electric fields and electromagnetic radiation that could theoretically have an effect on living tissue. A nonmoving static magnet produces only a magnetic field. Now, here is the key point: there is no evidence that magnetic fields have any significant effect, therapeutic or otherwise, on human tissue. You may respond by wondering “Wait a minute, what about the iron in our blood?” Fortunately, the iron in hemoglobin is not ferromagnetic (10). In other words, iron as it is configured in hemoglobin is not affected by magnets. This is quite fortunate for the millions of people who have been exposed to powerful magnetic fields during magnetic resonance imaging scans. If hemoglobin were ferromagnetic, then they would explode in the scanner. Perhaps, the lucky ones would only spin around in circles.
Even if magnets did have some effect on human tissue, what is the likelihood that it would be a healing effect? About zero. By analogy, of the approximately ten million known chemical compounds, only a few have healing effects. The vast majority, thousands upon thousands, are highly toxic. How many products on the shelves of Home Depot or Lowes would you like to taste test? If static magnets had any effect on human tissue there is no reason to believe that it would be a healing effect.
Anesthesiologists are experts in the management of pain. Anesthesiologists are trained in pain management. Many work in pain management clinics. As the name Anesthesia & Analgesia suggests, anesthesiologists are world-class pain researchers. The results presented by Cepeda et al. in this issue will be of special interest to the readers of Anesthesia & Analgesia. Patients interested in evidence-based medicine may find these results via Google, helping to dilute the hokum with real science. For readers wanting more information, a brief and very interesting review of magnet therapy can be found at the Quackwatch.org Internet site (11).
1. Cepeda MS, Carr DB, Sarquis T, et al. Static magnetic therapy does not decrease pain or opioid requirements: a randomized double blind trial. Anesth Analg 2007;104:290–4.
6. Finegold L, Flamm BL. Magnet therapy. Extraordinary claims, but no proved benefits. BMJ 2006;332:4.
8. National Center for Complementary and Alternative Medicine. National Institutes of Health Research Report. Questions and answers about using magnets to treat pain. Available at http://nccam.nih.gov/health/magnet/magnet.htm
. Accessed September 28, 2006.
10. Park RL. Voodoo science: the road from foolishness to fraud. Oxford: Oxford University Press, 2000.