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INTEGRATIVE MEDICINEBar Raised for CAM Research, Boom Lowered on Some RemediesWith herbal remedies available in everything from multivitamins to snack chips, and with public demand for alternative treatments like acupuncture rising, there has been a growing awareness that modern medicine must reckon with therapies once considered outside the realm of serious science. At the second annual International Scientific Conference on Complementary, Alternative and Integrative Medicine Research, April 12 to 14, more than 400 participants gathered to hear how popular treatments have fared under the scientific lens. Beyond the individual findings, the conference represents a critical point in the development of a field still in its infancy. David Eisenberg, a codirector of the conference and director of the HMS Division for Research and Education in Complementary and Integrative Medical Therapies and the Bernard Osher associate professor of medicine at HMS, has tracked the change in perception of complementary and alternative medicine (CAM) over the past decade, from intense skepticism to growing support, fueled by an influx of government research funding. Conference codirector Susan Folkman, director of the Osher Center for Integrative Medicine and professor of medicine at the University of California, San Francisco, observed, "This new field has a topography that sets it apart from other scientific fields." Newsworthy FailuresFor most areas of medical research, potential therapies come to the public's attention only when they begin to show promise in animal models or early clinical trials. Clinical trials of CAM therapies, on the other hand, are testing treatments that are already sitting in many people's medicine cabinets. Because these substances are already in use, "the public has a vested interest in all findings," Folkman said, be they positive or negative. So rather than simply hearing researchers unveil their successes, conference participants heard a series of results that were negative or neutral in addition to a few promising stories. And unlike negative trials of unknown compounds, the disappointments made headlines. For instance, researchers at the Osher Center for Integrative Medicine at UCSF found in an Internet-based, randomized, placebo-controlled study that neither kava kava nor valerian relieved anxiety or insomnia more than a placebo. Another double-blind, randomized, placebo-controlled trial found that guggal extract, widely used to treat elevated cholesterol in India, actually raised LDL cholesterol by an average of four percent, while a placebo lowered levels by five percent. That the therapy would actually worsen the condition "was certainly not what we expected," said lead author Philippe Szapary, assistant professor of medicine at the University of Pennsylvania School of Medicine. Designing a Mock MagnetNot only do CAM trials often face rigorous public scrutiny, researchers also struggle with unique issues of design and objectivity. For some, it is not always clear what constitutes a placebo, especially in cases where the mechanism of the therapy is unknown. When HMS investigators at Beth Israel Deaconess Medical Center wanted to test the efficacy of magnet therapy for osteoarthritis of the knee, constructing a believable placebo was a problem. Though few study participants will try to analyze the contents of their sugar pills, a "magnet" that doesn't stick to the refrigerator is obviously a fake. The team, led by research fellow Peter Wolsko, constructed a knee sleeve packed with magnets on the outside--to satisfy curious refrigerator testers in the group--with only a brass disk inside and no magnetic field reaching the knee. The results of the study on 22 adults found an initial benefit for those with real magnets after four hours of treatment, but this benefit was lost at all later time periods during the six-week trial. Wolsko believes the results were somewhat less important than the success of the placebo. Though participants had signed a form agreeing not to tamper with the devices, more than half of them later admitted they had tested the magnetic field. CAM researchers also face the burden of what Eisenberg called "unbundling the placebo." The placebo effect itself and the mind-body connection may be an integral part of some alternative therapies. CAM research has at times been more willing to examine this effect than modern mechanistic medicine. For instance, one study of acupuncture found that patients with chronic neck pain improved by 60 percent over the time of the trial--but so did patients receiving a sham intervention of stimulating acupuncture points with electrodes. The results raise questions about whether a nonspecific effect of treatment is responsible for the improvement--and whether it is really so bad to use a treatment that works, even if placebos do, too. In a presentation on how brain imaging can shed light on some of these issues, John Mazziotta cited a study published in Science last March that used PET imaging to show that placebos activate the same neural networks as do opioides in response to pain. "The placebo response overlapped almost entirely with the opioide response," he said. Active HerbsFacing skepticism from both believers and nonbelievers, CAM researchers must not only show whether therapies work but must "wrestle with the mechanism," said Eisenberg. In addition to clinical research, the conference featured several presentations on the basic science of traditional medicines. Some of these studies confirmed--at least initially--that herbal medicines have therapeutic biological activities, such as a study showing that a component of frankincense slowed the growth and motility of brain tumor cells. It is not surprising that traditional herbal remedies are bioactive. But the flip side is that a host of recent studies has shown several herbal remedies to interfere with the activity of other drugs. Martha Harkey, adjunct professor of medical pharmacology and toxicology at the University of California, Davis, presented a study showing that several extracts, including kava kava, Ginkgo biloba, garlic, and St. John's wort, alter the action of the detoxifying enzyme cytochrome p450, an important component of drug metabolism, in an in vitro assay. Eisenberg said the quality of the presentations reflects the growing support for CAM research nationally and internationally. In 1998, the National Center for Complementary and Alternative Medicine was established with the autonomy to independently select the studies it funds, which created "seismic changes for this field." While increasing the budget for CAM research, the national center has raised the standards required to receive funding. "This has brought the level of studies up," Eisenberg said. --Courtney Humphries |
