Therapeutic magnets are big business, taking in over $300 million per annum in the US and globally over $1 billion. You'd think that if so many people were buying such a lot of them, they'd be doing something good.
You can buy magnets to help your horse run faster, to improve the health of your dog, and even to improve your golf swing. You can buy seats, belts, bracelets, shoes, anything you feel like. If you're willing to buy it, someone will sell it to you. Magnets come in all sizes and strengths accompanied by the most extraordinary claims, the most common being that they improve your blood circulation and therefore help your body to recover from the knocks of daily living.
And of course, if there was any hint that they were doing no good, that they didn't work, the consumer protection lobby would be raising hell about it, right? Of course not. It doesn't work like that. Instead, it's left to methodical scientists conducting clinical trials to investigate these products, and one such study has just been published by Dr Stuart Richmond of the Department of Health Sciences, University of York, in the journal Complementary Therapies in Medicine.
He studied a group of patients suffering from osteoarthritis, a major target market for these magnetic devices. The trial tested the effect of a copper bracelet, two magnetic straps, and a demagnetised strap. The controlled, double-blind trial could identify where the placebo effect was occurring, and also whether, and in an what circumstances, there was a measurable effect. It was a methodologically sound trial.
The conclusions were no surprise to those who have some understanding of human biology and magnetism. The trial concluded that there was no evidence that the magnets had any effect on pain relief, stiffness, physical function, or medication use. They were useless.
It's a tempting prospect for chronic pain sufferers that some simple device will provide relief. After years of partial control of pain, continual loss of function, and the prospect of more of the same ahead, we can well understand the hope given to sufferers by the marketing claims.
After all, the theory behind these products sounds fairly plausible. In every red blood cell there's a haemoglobin molecule, and inside that – IRON! We all learned in school that iron is magnetic – case proved, right?
Well, again it just doesn't work like that. Unfortunately, blood itself is not magnetic. You can very easily test this for yourself with a magnet held near the skin. Does it attract blood and make a red mark? Does it repel blood and make a pale mark? No. A little further thought shows even more dramatically how wrong the idea is. In an MRI scan, the body is subjected to an intense magnetic field. If blood was attracted by this field, MRI scans would always be fatal. They're not.
So what's the difference between these therapeutic magnets and MRI scanners? The fact is that static magnets like bracelets have no effect on human tissue. To get even a weak effect, the MRI scanner has to use a radio-frequency field (not a static magnetic field) to alter the magnetic field of the hydrogen atoms in the water in the patient's body. This resulting rotating magnetic field of the hydrogen atom is very weak (and temporary) but with a very sensitive detector, it can be used to tell the difference between hard and soft tissue. A massive magnet is needed just to be able to get an image. This technology has nothing at all to do with the claims made for therapeutic magnetic bracelets.
Woo theories often start with a credible reference to some physical or medical facts, in this case magnetism. They then makes unsubstantiated claims which you are led to assume are also of the same veracity. That's the Woo jump from being a critical consumer to being a credulous believer, and if you're in pain, it's a very easy step to take.
As Jane Tadman of the Arthritis Research Campaign said: "Although there is a big public appetite for non-drug treatments from arthritis patients, we would not encourage them to spend a lot of money on products for which there is very little scientific evidence".
Of course, the purveyors of magnet Woo will say no one has yet proved that they don't work. But the burden of evidence is with the seller, not the buyer. If you sell something, you need to show it works. They can't, because the physics of the real world gets in the way. Let's see them produce their evidence before they make these claims. At least then vulnerable patients wouldn't be led to spend money on useless magnets.
It's high time these Woo merchants were called to book, and required to produce reproducible reliable evidence of efficacy, based on methodologically sound trials, before they can take money from vulnerable people.Powered by Sidelines