In 1991 previously healthy young women in Brussels started showing up at clinics with advanced kidney damage. An inquiry revealed that they had all attended the same weight-loss program and, due to a mix-up, had received the Chinese herb Aristolochia as part of the regimen. More than 100 women developed irreversible kidney damage requiring dialysis or transplantation, and a high percentage went on to develop cancer of the upper urinary tract.
Had it not been for the unusual nature of the outbreak and alert clinicians, the incident might well have gone unnoticed. As it turned out, the Brussels cluster dramatized in an unprecedented way the previously unacknowledged threat that can be posed by herbal remedies.
In the 25 years since the Brussels outbreak, we have learned a great deal about the use and harmful effects of toxic herbs. This knowledge, however, has not translated into policies to reduce the harm caused by botanicals. Instead, the World Health Organization has launched an ambitious program that flies in the face of the scientific evidence the organization demands elsewhere and shamelessly promotes the use of traditional medicine, including herbal treatments, that could be dangerous.