Recent discussions about the therapeutic use of magnets bring to mind the story of Madame Marie Curie, who discovered the x-ray. Curie and her husband suffered great damage to their fingers from the ionizing radiation they worked with during their research. Apparently they were not aware that their new diagnostic tool, although invisible, could have harmful effects.

The magnetic field has also been shown to have powerful effects - both healing and destructive - upon living systems. In our eagerness to find new therapeutic methods, I wonder if we may be getting carried in our use of magnets.

The effects of artificial magnetic fields on humans became startlingly evident during the early manned space flights. Both U.S. and Soviet scientists were forced to concede that magnetic fields might have a powerful effect upon human health and function. Subsequent investigations confirmed that changes in magnet field intensity, vector orientation and polarity exert significant influence on living systems in space.

These studies have implications for the earthbound as they refute several long-held scientific dogmas. For instance, one principle held that humans do not have any permanently magnetized materials in their tissues. In fact, the brain contains about five million single-domain crystals of magnetite per gram of tissue, and the meningeal membranes contain 100 million of these crystals per gram of tissue.

These findings are of particular interest to those working with the craniosacral system. It is possible that the energies perceived by craniosacral therapy practitioners as signals of membrane restrictions are related to these magnetite crystals. The mobilization of the meningeal membranes through craniosacral therapy may have an as-yet-uknown positive effect upon the magnetic aspects of these membranes.

Meanwhile, the earth's magnetic fields - called geomagnetic fields (GMF) - are constantly fluctuating due to internal and external influences. These fluctuations seem to be self-correcting, such that the natural magnetic fields remain within the limits that make earth habitable. Continental shifts; explosions; earthquakes; sunspots; eclipses; atmospheric pollutants; lightening; thunderstorms; hurricanes; and cyclones can influence the GMF.

For a simple example of how we are affected by subtle changes in the earth's magnetic field, consider what happens during a full moon: some people report experiencing irrational thoughts or malaise. The earth has an overall positive charge that increases during the full moon. Yet most people seem to feel and function better in an abundance of negative ions. It has also been noted that human oxygen consumption goes up during the full moon, and blood and lymph become somewhat less viscous.

The effects of magnetic fields also have been observed at a cellular level. A researcher at Cal Tech in Pasadena, California hypothesized that individual cells may possess sensory systems that respond to weak magnetic fields. He noticed that extremely low frequency (ELF) electromagnetic fields change the cellular protein structures, which disrupts the transport of proteins and other substances within the cells. Clearly, disruption of the magnetic field of a cell may ultimately disable it to some degree, and may even cause cell death.

By chance, I came across some startling examples of the effects of magnetic fields on living systems in a book by a farmer named Davis. He and a friend became curious about the effects of magnets on crops and farm animals. They divided vegetable seeds into two batches, then exposed them to either the north or south pole of a bar magnet before planting them.

The men noticed that the seeds exposed to the south pole grew more rapidly, and the vegetables grew much larger than the others. Unfortunately, they were also dry, woody and inedible. The north pole vegetables, although smaller, were moist, tender and pleasant tasting.

Next, the men exposed fertilized chicken eggs to magnets. Again, the chickens exposed to the north pole grew slower and remained smaller than the other chickens. Yet here's what really caught Davis' attention: the south-pole chickens were very aggressive. They would fight to the death. By contrast, the smaller north-pole chickens were quite peaceful. If allowed to mingle, the south-pole chickens would attack and kill the other chickens, then pick apart their victims and eat some of the flesh. This particular observation suggests the possibility of hormonal effects caused by the magnet.

After this book piqued my curiosity, I discovered, along with Jon Vredevoogd, my co-researcher at Michigan State University, that we could use magnetic fields to cause and relieve headaches, nausea and mental confusion. We also found that increases and decreases in craniosacral system pulse amplitude were closely related to changing magnetic fields.

I suggest that, because human and other living systems appear able to create their own permanent magnetic materials, they possess some ability, albeit limited, to modify most external magnetic fields to acceptable levels. It also seems reasonable to expect that long-term exposure to unnatural external magnetic fields might ultimately drain these protective systems of their ability to neutralize and/or modify the effects of these external magnetic fields.

If the body's defenses are not able to neutralize abnormal external magnetic fields, many serious things can happen. Magnetic field exposure could lead to distortion in the cellular production of hormones, various cellular dysfunctions and ultimately, cell death.

Externally created magnetic fields can also interfere with normal cellular activity by creating a "static" that interferes with communication between separate cells and structures within cells. This type of exposure has been seen to interfere with the cell's ability to block disease-causing proteins. Thus, the cell may become more vulnerable to disease-causing invaders such as viruses and bacteria, and to the acceptance of toxic substances.

My experience, personally and with patients, has shown that the autonomic nervous system also is sensitive to changes in the magnetic fields. Research supports these observations, noting that the long-term use of external magnets can cause autonomic systems to change their set points and require time to readjust once the magnets are removed. These autonomic effects are manifest in episodes of cardiac failure, brain dysfunction, blood viscosity changes and gastrointestinal problems.

On the bright side, reports are coming in about the successful use of magnets to stimulate nerve growth. I believe this effect may occur, at least partially, because the external field may reactivate magnetic crystals in the nerves. I have only worked with several spinal-cord-injury patients using magnets for limited periods. They all had secondary paraplegia and sensory loss. In sensory and motor responses, the magnetic stimulation produced more definite subjective responses than electrical stimulations.

However, based on the current evidence, I recommend exercising the utmost care when using magnets as a long-term treatment. This invisible, powerful modality is not without risk. I will err on the side of caution until I am convinced that we know what we are doing. The Curies might have faired better had they been more wary.