WASHINGTON, D.C.--Quality control of dietary supplements is a major stumbling block for any study of the widely used compounds, a panel of the National Academies of Sciences Institute of Medicine has found. The panel--which reviewed other aspects of complementary and alternative medicine as well--wants to strengthen existing laws and also give manufacturers an incentive to study the efficacy of their products.
The report was commissioned in 2002, principally by the National Center for Complementary and Alternative Medicine, to study the growing popularity of alternative medicine and associated scientific and policy issues. "The main message is that the same rules [of evidence] should be applied" to alternative therapies as to standard medical treatments, says physician Stuart Bondurant of the Georgetown University Medical Center in Washington, D.C., who chaired the panel. As for which practices to evaluate first, the panel recommended that factors such as biologically plausible mechanisms and common diseases be considered.
A key problem with advancing research on dietary supplements, the panel found, is variation in composition. "We're at an impasse," said panel member David Eisenberg, a physician in the Division for Research and Education in Complementary and Integrative Medical Therapies at Harvard Medical School in Boston, Massachusetts. "We're not sure that what's on the label is what's in the bottle." The panel urged Congress to revise its Dietary Supplement Health and Education Act (DSHEA) of 1994, which established that supplements should be considered as food rather than as drugs. The panel also recommended that incentives be provided for companies to fund research, although it did not provide a specific plan.
Medical experts say these changes are long overdue. "They are right on the mark," says Mary Anne Kimble-Soda, a pharmacologist at the University of California, San Francisco. But she is not optimistic that Congress will act. Phil Fontanarosa, executive deputy editor of the Journal of the American Medical Association, agrees that DSHEA should be amended and hopes that the report will provide useful guidance to those who study alternative medicine. "The net effect of this will be to raise the level of rigor of this kind of research."
Michael McGuffin, president of the American Herbal Product Association, based in Silver Spring, Maryland, says that the current form of DSHEA would be adequate to ensure good manufacturing practices--when the Food and Drug Administration issues final guidance.