Magnetic Therapy- It’s effective… isn’t it??
If you read the promotional material for Magnetic Therapy products they sound absolutely amazing. They are promoted as a drug free, non invasive and effective way of restoring your horse to peak performance, cutting down on recovery time, and relieving tired, aching joints and muscles. They allegedly increase muscle elasticity and return of normal range of motion and therefore result in less chance of injury.
Their persuasively presented claims are simply not supported by legitimate scientific evidence. The very few studies that do show a positive effect from wearing magnets admit that they can not hide from the participants whether they are wearing magnets or not. Thus the results can not be differentiated from placebo, or the benefit people get just because they believe in the treatment they are receiving. The majority of studies show absolutely no benefit from wearing any type of magnetic product.
Magnetic pads that radiate an unchanging magnetic field can be applied to horses via any number of boots, blankets or pads. Because the static magnetic fields don’t change, there can be no electrical effect. Thus proponents of magnetic products use another mechanism to explain the purported beneficial effects, an increase in local blood circulation.
Blood does contain electrically charged ions. A physics principle known as Faraday’s law states that a magnetic field will exert a force on a moving ionic current. An extension of Faraday’s law called the Hall effect states that when a magnetic field is placed perpendicular to the direction of the flow of an electric current flow, it will tend to deflect and separate the charged ions. This separation of ionic charges produces an electromotive force, in theory a very small amount of heat.
The problem with using Faraday’s law and the Hall effect to explain the purported effects of static magnetic pads is that the magnitude of the force applied by the field is infinitesimally small. This is for two reasons, first the magnetic field that is being applied to the tissues is extremely weak and secondly the flow of the blood is extremely slow, especially when compared to the flow of electric current.
Magnetic field strength is measured by Gauss. Horse magnets are advertised as having a therapeutic strength of between 10 and 500 Gauss at the level of the magnet. However at a distance of 1cm this strength decreases to only 1 Gauss. 1 Gauss is approximately the magnetic field strength of the earth. The velocity of the blood is approximately 0.5 to 1 cm per second.
If you generously consider a magnetic field of 250 Gauss and the velocity of blood at 1cm per second, the electric field seen by an ion in the blood flow will be about 2.5x Volts/meter/sec. The thermal agitation imparted by the natural heat of the horse’s body will cause about 10 million times more movement of the ions in the blood than a 250 Gauss magnet.
Some manufacturers claim that they can increase the effects of charge separation by alternating north and south magnetic poles. This is commonly seen in fridge magnets. However this just decreases the magnetic field strength of the magnet because the magnetic fields tend to cancel each other out as they extend from the magnet. Try an experiment with a magnet on your fridge. Put one piece of paper between the magnet and the fridge, now, one by one, keep adding pieces of paper. How many can you put under the magnet until it stops working and the papers fall to the floor. My best was 5. If the magnetic field can not pass through more than 5 pieces of paper, how can it have any effect on the tissues under your horse’s hair? Especially after having to also pass through whatever pad or boot that is holding the magnet in place.
Some proponents of Magnetic Therapy try to give their products extra credence by associating their products with the accepted use of magnets in MRI machines used in scientific medicine. However MRI’s are just diagnostic machines, not therapeutic. They use an approximately 10,000 Gauss magnetic field, so if you want to believe that magnets have a serious effect on your blood flow, an MRI scan would probably blow you to bits. Whilst people come out of an MRI scan knowing what is wrong with them, none come out healed.
Now what about personal experience and anecdotal evidence? What about the person who states that using magnetic therapy boots on their horse has been very helpful for rehabbing after soft tissue injuries. Horses are not susceptible to the placebo effect!! But their owners are and for this reason anecdotal evidence can in no way be considered scientific proof. People who are gullible enough to try magnets will be easily persuaded to attribute any improvements in their horse solely to the magnets. But what other treatments did the horse receive, rest, anti-inflammatorys, bandaging. Would the horse have gotten better anyway? Most people try treatments when their horse has a problem. The most likely thing to happen after an injury is that the injury improves. Attributing the horse’s natural healing ability to magnets is the same as saying that my horse got better because every day I spent 10 minutes whispering healing mantras into his ear. You may well have done this but he was going to get better anyway.
Magnetic therapy is pseudoscience. Magnets have zero health benefits whatsoever. There is no conceivable mechanism under which they might act, and no reproducible studies have found that magnets provide health benefits. Save your money and if your horse has a real problem go and see a good vet, get the problem diagnosed and treated with scientifically tested, clinically proven treatments.