More than 50% of Canadians use natural health products such as vitamins, homeopathic remedies, traditional therapies and herbal medicines. Some herbal products have been well studied, others less so. Some are benign, while others have potential adverse effects, either alone or in combination with commonly prescribed pharmaceuticals. Health Canada has released several warnings concerning natural health products (www.hc-sc.gc.ca/english/warnings.htm). In 1999, Health Minister Allan Rock announced the creation of a new regulatory authority, the Office of Natural Health Products (www.hc-sc.gc.ca/hpb/onhp), to oversee herbal and traditional medicines. Its Web site includes a report of a 1999 conference setting its research agenda and its proposed regulatory framework for clinical trials involving natural health products. Levels of evidence are to be reviewed this fall.
Online information on natural products is not only widely abundant but also widely variable in quality. Well-established resources include the National Center for Complementary and Alternative Medicine, which is run by the National Institutes of Health. It produces fact sheets and literature summaries (nccam.nih.gov). In conjunction with PubMed, NCCAM has developed a PubMed search configured for complementary and alternative therapies (www.nlm.nih.gov/nccam/camonpubmed.html). The Office of Dietary Supplements (ods.od.nih.gov) offers the International Bibliographic Information on Dietary Supplements database (ods.od.nih .gov/databases/ibids.html), which covers vitamins, minerals and selected biologic products in common use in North America. The Cochrane Collaboration (hiru.mcmaster.ca/cochrane) has reviewed evidence for the efficacy of established herbs such as St. John's wort.
The Alternative Medicine Foundation maintains a database on herbal medicines, HerbMed (www.herbmed.org), which lists published evidence (whether clinical trial or longstanding folk use), warnings, preparations and mechanisms of action for commonly used herbs. On the American Cancer Society Web site (www.cancer.org), the menu-heading for complementary and alternative therapies links to patient information, while research, review and news articles can be found through the site search. For users of hand-held computers, files of “Common Herbs” and “Herbal Reference Guide” are available free from the Peripheral Brain site (pbrain.hypermart.net).