Six Popular Herbal Therapies Have Mixed Risk-Benefit Profiles
January 2, 2002 (American College of Physicians-American Society of Internal Medicine) -- A review of published data on the effectiveness and safety of six herbal therapies finds:
· Ginkgo: Some positive effect on dementia and leg pain due to poor circulation, questionable effect on memory loss and unclear effect on ringing in the ears.
· St John's Wort: Effective for mild depression but can alter the action of prescription drugs such as anticoagulants, oral contraceptives and antiviral agents. (Note: also increased sensitivity to sunlight).
· Ginseng: No evidence that it is effective for any condition and has some severe side effects.
· Echinacea: Different brands vary considerably in effectiveness. May help treat or prevent upper respiratory tract infections, but data are weak and inconclusive. Side effects include allergic reactions.
· Saw palmetto: Reduces symptoms of benign prostate disease in the short term.
· Kava: Effective for short-term treatment for anxiety.
Accurate assessment is difficult, the author says, because existing clinical trials are "too few, too small, and too short"; lack of standardization and quality control make it hard to know what the herbal products contain or if they are free of contamination, and a plethora of books on herbal medicines "represent more of a risk to the health of the reader than a helpful source of knowledge." The author identifies and ranks some newer books on herbal medicines. Although the growing popularity of herbal medicines probably reflects the public perception that they have no negative side effects, the author stresses that all herbal products have some risks.