Two additional studies show magnets may also be helpful in treating some mental illnesses. Yale University researchers recently concluded that a form of magnet therapy reduced auditory hallucinations in patients with schizophrenia, and a study at the University of Florida in Gainesville found magnetic stimulation helpful in patients with clinical depression.
 
What remains a question in all these studies is exactly how magnets work.
 
"We do not have a clear explanation for the significant and quick pain relief observed by the patients in our study," says Dr. Carlos Vallbona, co-investigator of the Baylor College research.
 
In Baylor's study of 50 people, Vallbona found that a small magnet strapped to the most sensitive sore spots of post-polio patients provided pain relief. "It's possible that the magnetic energy affects the pain receptors in the joints or muscles, or lowers the sensation of pain in the brain," adds Vallbona, who is a professor of family and community medicine.
 
Still too many unknowns
 
Not all studies, however, have found magnets produce a positive response. Researchers at the Veterans Affairs Medical Center in Prescott, Ariz., for example, reported recently that magnets offered no verifiable help to patients with chronic low back pain.
 
Even Vallbona urges caution. "There are still too many unknowns," he says.
 
And what is becoming known is not all healthy. For example, the researchers at Brown University found that strong magnetic fields have a definite effect on individual cells, altering the way they divide. 

That could be dangerous to a developing fetus, especially in the first trimester, Vallbona says, adding, "I would not recommend magnets to pregnant women or patients with pacemakers." 

Parker and other investigators at the University of Tennessee, including principal researcher Dr. Candace Brown, say their research suggests that pain relief is related to the length of exposure to the magnet. In the clinical trial, there were no significant changes in the women who had chronic pelvis pain after two weeks. But after three weeks, 60 percent of the women with active magnets -- and 33 percent of those with placebo magnets -- reported less pain.
 
One key to effective magnet therapy could be the strength of the magnets, says Thomas Skalak, the director of the University of Virginia's Center for the Engineering of Wound Prevention and Repair. "You can't take a single refrigerator magnet and expect it to do anything. For any potential results, you'd need the equivalent of 10 to 100 refrigerator magnets," he adds.
 

These aren't refrigerator magnets
 
The strength of the magnets in the Baylor and the University of Tennessee studies were both more than 15 times that of a refrigerator magnet.
 
Skalak is the recipient of one of two grants for magnetic studies that were recently awarded to the University of Virginia by the National Institutes of Health. Skalak is studying whether static magnets can increase blood flow and consequently have a positive effect on healing. The other study will focus on the effects of magnets on nerve cells.
 

Both are follow-ups to work initiated by Ann Gill Taylor, director of the university's Center for the Study of Complimentary and Alternative Therapies in its School of Nursing. For several years, she's been investigating whether magnets can provide relief for such conditions as low back pain, arthritis and fibromyalgia, a condition characterized by widespread pain, sleep disturbances, fatigue and often depression.
 
Skalak, who participated in Taylor's research, says her study has demonstrated that magnets can have a strong positive effect on blood flow. He cautions, however, that the study was too limited to be statistically significant.
 
Taylor is hoping to publish the full results of her study sometime this year, and does not want to comment on them before that.
 
Until then, the skeptics remain unswayed.
 
Dr. Stephen Barrett, a retired psychiatrist from Allentown, Pa., and author of http://QuackWatch.com, a Web site designed to debunk medical claims, says he's curious whether studies like the one at Baylor can be duplicated and whether magnets can relieve pain in patients with wide-ranging ailments.
 
"I don't think there's a greater market for a product with less evidence," he says. "I remain skeptical that small, static magnets can relieve pain or influence the course of any disease. Some products are too weak to provide a magnetic field that penetrates the skin or are complete fakes that exert no magnetic force whatsoever."