Magnetic therapy has a $5 billion world market, but does it work? Biomedical engineering professor Thomas Skalak set out to investigate the claim that magnetic therapy increases blood flow.

With a five-year, $875,000 grant from the National Institutes of Health’s National Center for Complementary and Alternative Medicine, Skalak has been studying the science behind the anecdotal evidence. People use magnets to treat a range of conditions, from arthritis to depression, but scientific proof of their healing properties is lacking.

Skalak’s lab leads the field in the area of microcirculation research, the study of blood flow through the body’s tiniest blood vessels. His latest study, published in the November issue of the American Journal of Physiology, involved lab rats given inflammatory agents to simulate tissue injury. When magnetic therapy was applied immediately, it significantly reduced swelling. Since muscle bruising and joint sprains are common injuries, the findings have considerable implications. “If an injury doesn’t swell, it will heal faster—and the person will experience less pain and better mobility,” says Skalak, who plans to continue testing in elite athletes.