Magnets have fascinated and frightened people since their discovery more than 3,000 years ago.
Legend has it the first magnet was found by an ancient Greek shepherd called Magnes: after he noticed his shoes’ nails were sticking to the ground, he began digging and discovered pieces of magnetite, a natural magnetic material.
Magnets have long been used by folk healers for scores of ailments, from pain and ulcers, to impotence and wound healing. Although many dubious health claims have been made, magnets are increasingly being used in mainstream medicine. We look at how . . .
To remove a nail
Magnets remove metal objects, such as splinters from eyes and pins and nails from other parts of the body. Objects that have been swallowed may be removed using a cylindrical magnet attached to a long flexible rod encased in a rubber sheath that’s navigated down the gastrointestinal tract until it reaches the foreign body. The object is attracted to the magnet and removed.
For teeth straightening, small magnets are fixed to the teeth to either attract or repel each other. The technique was pioneered in the UK in the Nineties.
For dentures, a circular magnet, about 4 mm wide, is located inside the plastic denture, while the plates, which are the same size, are implanted onto the remaining teeth either side, or anchored to the roots of teeth or to implants.
‘Magnets have the advantage that their small size makes them ideal for holding dentures in place,’ explains Damien Walmsley, a professor of restorative dentistry at Birmingham University.
Magnets have been approved by the National Institute for Health and Care Excellence as a treatment for migraine.
Known as transcranial magnetic stimulation (TMS), it involves a portable device being held to the scalp to send brief magnetic pulses through the skin at the touch of a button.
Studies have shown that transcranial magnetic pulses may block the aura (visual disturbances) that can occur with migraine. One theory is that the treatment has a damping down effect on nerve cells.
The U.S. Food and Drug Administration has also now approved it for depression. A U.S. trial five years ago found 14 per cent of patients achieved remission from major depression compared with 5 per cent with placebo.
But Carmine Pariante, a professor of biological psychiatry at King’s College London, says: ‘It is not as effective as electroconvulsive therapy (ECT) for those patients with severe depression who are at risk of suicide or self-neglect, and who have not responded to available antidepressants.’
In another form of treatment, magnetic seizure therapy (MST), stronger magnetic pulses are used to trigger a seizure. It is meant to have fewer cognitive side-effects such as memory loss and faster recovery than ECT.
A magnetic collar worn around the neck during sleep could be a new way to tackle snoring.
The collar contains a magnet which is worn over a second magnet surgically implanted in the hyoid, a horseshoe-shaped bone in the throat. When the collar is switched on, the implanted magnet, the Magnap, is pulled towards the collar to keep the airway open.
Patients have been implanted with the device as part of a new trial at the University of California, San Francisco.
Hollow plastic tubes called catheters are an essential tool for heart surgeons, for diagnosing and treating many conditions, including blood clots and aneurysms.
The catheters, which can ferry different surgical tools, are usually navigated though the blood vessels by stiff guide wires, but this carries risks including perforation of the heart wall. With magnetic navigation, however, the guide wires are not needed. Instead two magnets are positioned on either side of the patient to create a magnetic field in the chest.
The tip of the catheter holds a small magnet, and by changing the direction of the outer magnets, it can be steered to its destination. It can travel around sharp bends, and through narrow blood vessels.
This technique is currently used only at the Royal Brompton Hospital in London. ‘Since the navigation is guided by the magnetic field, the movement of the catheter is very precise,’ says Dr Sonya Babu-Narayan, a British Heart Foundation-funded honorary consultant cardiologist at the trust.
Perhaps the most widespread use of magnets is to diagnose conditions with Magnetic Resonance Imaging (MRI). This non-invasive imaging technology uses powerful magnets and radiowaves to look inside a patient and produce 3D images.
A strong magnetic field makes water molecules in the body ‘wobble’ — and this wobble sends out radio signals which are detected by the MRI: the strength of these signals varies with tissue type.
Where there is a lot of water, such as in muscle, the signal is strong, but where there is less water, such as bone, the signal is weak. These varying strengths enable the MRI scanner to create a 3D image. The technology has revolutionised diagnostic medicine by revealing images of the body’s soft tissues and organs in great detail. Based on the same technology, MRI can examine blood flow in the brain, detecting changes in oxygen levels — a sign of how active brain cells are.
Dr Adam Perkins at the Institute of Psychiatry, Psychology and Neuroscience, King’s College London, has used it to locate areas of the brain involved in worrying. ‘Our aim is to improve the detection, diagnosis and treatment of illnesses such as anxiety,’ he says.
Between 5 and 10 per cent of fractures don’t heal properly, according to a 2013 Chinese study published in the journal BMC Musculoskeletal Disorders.
But the researchers found that holding a magnet over the break can help: 77.4 per cent of the bones healed at four months, compared with 48.1 per cent in a control group, the study found.
One theory is that the healing process sometimes stalls and that the magnetic stimulation re-activates the repair process.
The treatment is also used to boost bone density. A study at Cairo University last year found that stimulation with a pulsed electromagnetic field was up to five times more effective than exercise for boosting bone density.
Researchers compared the effects of magnet therapy given in three 30-minute sessions a week for three months, with exercise sessions of a similar length.
The study, involving 30 women aged 60 to 70, found that bone density at the top of the thigh bone increased by 15.5 per cent with stimulation, but only 3.2 per cent after exercising, according to the findings published in the journal Clinical Interventions in Aging. One theory is these fields can increase calcium in bone.
‘There is good evidence of the importance of magnetic fields and fracture healing,’ says Greg Packer, a consultant orthopaedic surgeon at Spire Wellesley and Southend University Hospital.
‘Pulsed magnetic fields are more commonly used, rather than magnets, to help mend fractures where they are slow to heal or in high-risk patients.’
The problem with many pills and capsules is that they do not dissolve at exactly the right site in the gastrointestinal tract to be absorbed into the bloodstream. A magnetic pill system being developed by Brown University in the U.S. is designed to solve the problem by holding a pill in the right place.
The system consists of gelatine capsules that contain a tiny magnet as well as the medication, and an external magnet.
In another version of this approach, tiny magnetic beads are injected along with clot-busting drugs into the blood of patients who have suffered a stroke — a magnet is then placed next to the patient’s head.
The magnetic force helps push the drugs through the blocked vessels to break down the life-threatening clot. A study presented at the American Stroke Association showed that patients given ‘magnetic’ versions of drugs within three hours had a significantly reduced degree of disability afterwards.
Dr Richard Perry, a consultant neurologist and stroke specialist at University College London Hospitals, where the treatment is being studied, told Good Health: ‘It’s like a motorway blocked by a crash, where the emergency services have difficulty getting through.
‘The drugs can take some time to reach the clot. This approach of using iron microbeads to stir the blood and improve access of the clot-busting drug is exciting.’
© Daily Mail