Jan 14, 2008
Attractive Health Measures or Magnetic Manure
We probably all know at least one person who swears by their magnetic charm bracelet for preventing travel sickness, reducing arthritic pain or even helping them through situations that induce an attack of social anxiety disorder. These bracelets and other devices (some are in the form of headbands, others pendants, blankets, knee braces, shoe inserts, there’s even one you wear in your pants to improve your sex life) use magnets of a similar strength to those that make shopping lists stick to your refrigerator or let your kids spell out rude words without you realising…
…in other words, they’re not very strong and so probably have absolutely no physiological effect whatsoever. So, this $5billion industry founded in ancient Greek mythology is almost on a par with homeopathy for having no real scientific basis. Or is it?
Serious research, being carried out in a serious university laboratory, with serious financial backing recently hit the headlines with proclamations that a short application of a magnetic field to an inflamed joint could somehow improve blood flow and reduce swelling. Thomas Skalak, chairman of biomedical engineering at the University of Virginia and his colleagues lead the field in the area of microcirculation research, the study of blood flow through the body’s tiniest blood vessels. This status presumably helped them secure $875,000 of US taxpayers’ money from the National Institutes of Health’s National Center for Complementary and Alternative Medicine.
Initially, they set out to examine a claim made by the companies that sell “therapeutic” magnets: that these devices somehow increase blood flow. Skalak’s team used magnets of 70 milliTesla (mT) field strength, which is about ten times stronger than a common refrigerator magnet, but still very weak, the magnetic field of an MRI machine, for instance, is up to about 3000 milliTesla (3 T in other words). The researchers measured blood vessel diameter before and after placing the magnets up against lab rats.
They found that the magnets seemingly had a significant effect on blood vessels. Those that had been dilated became narrower and those that were previously constricted widened. Apparently, this implies that the magnetic field could induce vessel relaxation in tissues with constrained blood supply, ultimately increasing blood flow; how the magnet knows which way to stimulate the effect is not known. In a more recent study, the team treated the hind paws of anaesthetized rats with inflammatory agents to simulate tissue injury. Therapeutic magnets were then applied to the swollen paws immediately. The researchers say they say significant reduction in swelling (oedema), although there was no effect if there was any delay between injury and application.
According to Skalak, “The FDA regulates specific claims of medical efficacy, but in general static magnetic fields are viewed as safe.” So, could magnets be used to improve blood flow following muscle injury, say, as many of the headlines surrounding this press release claimed?
Well, what I’d first like to know, is did the researchers use a double-blind control? Did they, for instance, apply non-magnetic objects of equal size, shape and weight and at the same temperature to a second set of inflamed rat hind paws to examine whether those had any effect on blood vessel dilation? Did they have a set of inflamed rats that were not treated at all? How did those groups respond? The research paper on which the press release is based was published online in November 2007 in the American Journal of Physiology and Heart Circulatory Physiology.
Given that one of the major tenets of sports injury treatment is ice and compression could it be that the very act of pressing an object against the inflamed joint simply acted as a compressive heatsink, reducing local temperature of the inflamed region and at the same time temporarily reducing blood flow during the compression?
It’s just a thought, but couldn’t any metallic object of a reasonable size, 10-20 mm would be adequate for a rat paw, act as a cold compress, asks my good friend Stephan Logan. Logan supplies scientific educational equipment, including neodymium rare earth magnets, and points out that these have a field strength of several thousand milliTesla (1.3 T is typical for the standard neo magnet N42) and so has a keen interest in scientific claims made about much weaker magnets, such as those used in the experiments, knowing that a nasty pinch when flesh is trapped between two neo magnets is one of the well-known physiological effects but has nothing to do with mystical field effects
The Virginia press release, and consequently much of the media, claim that since muscle bruising and joint sprains are the most common injuries worldwide, Skalak’s discovery has “significant implications”. He rightly points out that, “If an injury doesn’t swell, it will heal faster – and the person will experience less pain and better mobility.” The extrapolation of the magnetic research to the notion that “magnets could be used in much the same way ice packs and compression are now used for everyday sprains, bumps, and bruises, but with more beneficial results, is not necessarily supported.
Magnets could be used, but where is the evidence that they reduce swelling any more than a conventional cold compress? Indeed, does injecting a rat’s foot with an inflammatory chemical simulate adequately a sprain or strain? The release says, “The ready availability and low cost of this treatment could produce huge gains in worker productivity and quality of life.” That’s a big extrapolation from a small laboratory study to the whole of sports injury medicine. Anyway, if commercialised are these therapeutic magnet ever likely to be as cheap and readily available as a bag of frozen peas? I doubt it.
Hi, a number of years ago a friend of mine seen a advert for magets for back pain, the price was £35.00p money back guarantee if they did not work, this was in spain, shortly after he put it on
he told me it was the first time in years he had been pain free. Now for my story 28/3/09 the pain in my knee is hurting bad i play golf and i am ready to give up, a friend tells me his story
about the pain he had suffered, and tells me how he cured it. I contacted a company called
Magnapulse who sent me a knee strap with four large magnets £29.00p + £3.00p del. I have been pain free since, back playing golf and bowls, so who’s kidding who about a plascebo affect
now it does not cure it, but it sure takes the pain away, and i do not have to wear it all the time.
Would like to hear your reply.
The UK had 5 homeopathic hospitals funded by the National Health Service (NHS). One has been closed…four to go!
db
I would not usually cite the Daily Mail, but an item junking magnet therapy caught my eye today because it mentioned how no one would survive an MRI scan if magnets had the kinds of effects quacks claim, which struck a chord and is pertinent to this discussion even if some of their phrasing is sensationalist – http://tinyurl.com/yurv2o
db
Thanks Mike for the follow up. You must admit that for every dozen “genuine” alternative (I thought the word was complementary these days) there are a million quacks perveying snake oil and pink medicine. Moreover, many “Western” acupuncturists have tried to disengage their practice from the Chinese tradition because of the mystical associations of chi (life force, energy) etc.
There is, however, no doubt that the placebo effect works, and yes, you’re probably right that the patient needs to think they are being “treated” in some way. However, even being told that you are receiving a placebo sometimes seems to work. As to the dogs and rats. The dog is a single anecdotal instance of recovery for whatever reason, putatively just a spontaneous remission, who knows? The rats, on the other hand, were in a trial and did not need to know about placebos and magnetism. Indeed, as I’ve said, I reckon the evidence points to a very simple mechanism taking place in the treatment and that is simply the rapid withdrawal of heat from the “injury” site by the thermal conductivity of the metal placed against it.
Incidentally, I don’t think it’s arrogant of medicine to be healthily skeptical of
alternativecomplementary practices, as I said for every one practice for which there is perhaps some evidence there are a thousand healers and charlatans who are taking money from desperate individuals and offering nothing more than a proverbial shoulder to lean on (which isn’t necessarily all bad, but could be got much cheaper elsewhere).db
Hi David,
The word ‘quack’ is habitually used by the medical establishment whenever they wish to ridicule someone who does not employ their methods or use their chemicals. Would the Norwegian ‘alternative’ therapist, who in the words of his attempted indictment “illegally cured a seriously ill person” be classified as a ‘quack’ or just someone who uses different methods? I’m sure accupuncture was once regarded as ‘quackery’, but it is now seen as being effective for a wide range of complaints. Something which the Chinese could have told us, if only we’d been prepared to listen more and scoff less!
Whenever something new or different appears, the establishment’s first reaction is to ridicule it, then to subject the newcomer to vilification and attempt to stamp it out, then when it won’t go away to finally embrace it as something they were aware of all along and to claim it as their own. However, I digress slightly…
Wikipedia has some interesting information on placebos, stating it is associated with the patient’s belief that the form of treatment they are about to receive will work. The variable results from placebos is probably explained by one person’s belief being stronger than another’s. I have seen a programme where a doctor performed a mock knee operation, with full theatre staff, on a man who was at the end of his tether with pain. When interviewed afterwards, the patient stated he could now dance with his wife and live a normal life. The doctor was at first reluctant to carry out this ‘quack’ operation, fearing ridicule by his peers but was himself astounded at the outcome. That is one man who’s mind has grown just a little.
Which brings us back to rats and dogs. The scientists found a change in the rats, and my neighbour’s dog was greatly improved, by the application of a magnet. For the placebo effect to work, the patient has to be aware that they are being treated and to have faith in the medication/doctor. I’m certain my neighbour would have been kind and comforting to his dog, when he found it could not jump onto his bed, and I’m sure the rats never thought “Ah, this looks like it just might do me some good, for once!” so I argue that the placebo effect is not applicable in these situation, as there was no prior knowledge or anticipation of a successful outcome.
If the rats or dog did not take a chemical to cause their physiological changes, and a placebo effect seems unlikely, then I agree with you that something else must be going on which we do not fully understand. Do you, or any of the original contributors at the start of this debate, have any idea what effect could be causing these changes?
Sincerely,
Mike Jozefiak
Ps Many thanks David for rescuing and ironing out my original letter from the trash bin!