Dr. Edzard Ernst, MD, Professor of Complementary Medicine at the University of Exeter has just released a major report on the safety of herbal medicines. Dr. Ernst surveyed the medical literature between 1992 and 1996 for reports concerning adverse effects of herbal remedies.

Among his findings are:

  * Royal jelly has been linked to several cases of severe bronchospasm;
  * Twenty-two cases of severe toxic effects involving pennyroyal have been reported;
  * Germander has been linked to 30 cases of acute liver failure;
  * Chaparral, comfrey and skullcap have all been linked to liver problems and the shiitake mushroom has been associated with dermatitis;
  * Chinese herbal medicines have been linked to a host of adverse effects and are often contaminated, especially with heavy metals;
  * Siberian ginseng can interact with digoxin, licorice with prednisone, and some Chinese herbal preparations with warfarin;
  * Four per cent (108) of 2695 patients admitted to a Taiwanese hospital had drug-related problems. Herbal medicines ranked third among the categories of medicines responsible for causing adverse effects;
  * Out of 1701 patients admitted to a Hong Kong hospital three were admitted because of adverse reactions to Chinese herbal drugs;
  * The London-based National Poisons Unit received a total of 1070 enquiries relating to herbal and other traditional medicines between January 1983 and March 1989.

Dr. Ernst concludes that the following herbal medicines are safe: camomile, garlic, Ginkgo biloba, peppermint, sabal, saw palmetto, and St. John’s wort. He also points out that herbal remedies often are safer than the corresponding pharmaceutical drugs. For instance, St. John’s wort has fewer side effects than synthetic antidepressants. Herbal remedies for prostate problems are as effective and significantly safer than the popular drug Finasteride and a mixture of fennel, peppermint and wormwood is more effective and far safer then metoclopramide. Editor’s note: More than 80 per cent of the world’s population rely on herbal medicines to cure their illnesses and annual sales in Europe and the United States exceed $8 billion. Dr. Ernst’s exhaustive study documents a total of 37 fatalities and less than 200 other adverse effects involving herbal remedies during a five-year period. That works out to an average of 7 fatalities and less than 40 adverse events per year ascribable to the use of herbal medicines. Considering that in the United States alone more than 7500 people die every year from taking nonsteroidal anti-inflammatory drugs and over 750,000 people experience an adverse drug event within American hospitals every year it is clear that herbal medicines are actually remarkably safe.

Ernst, Edzard. Harmless herbs? A review of the recent literature. American Journal of Medicine, Vol. 104, February 1998, pp. 170-78