FRIDAY, Jan. 4, 2002 (HealthDayNews) -- Some of the six best-selling herbal treatments may not live up to their claims, and one may be useless, a new report says.
The study, conducted by noted British alternative medicine researcher Dr. Edzard Ernst, looked at a compilation of medical literature on gingko biloba, St. John's wort, echinacea, ginseng, saw palmetto and kava, which together ring up more than $590 million in sales annually in the United States alone.
His study appears in the current issue of The Annals of Internal Medicine.
The study results aren't surprising, says another alternative medicine expert, Dr. James Dillard, clinical medical advisor at the Rosenthal Center of Alternative and Complementary Medicine at Columbia University in New York City.
"Doctors who are familiar with prescribing these treatments are well aware of what the studies show, and both the value of these treatments and their limitations," says Dillard.
"However, I think the study is very valuable for physicians who have not had the opportunity to research these treatments, or especially for those consumers who may be self-treating without knowing what they can expect in terms of proven results," he says.
Of the six herbs, the one that came up the clear loser in Ernst's study was ginseng.
"Well-conducted clinical trials do not support the efficacy of ginseng to treat any condition," he writes, adding 16 clinical trials used ginseng for a variety of ailments, and all yielded poor results.
Ernst's research also indicated ginseng's potential for adverse effects, including insomnia, diarrhea, vaginal bleeding, severe headaches, hypertension, hypotension, and nausea.
People with heart disease, blood pressure problems or diabetes should avoid the herb, Dillard says.
He's unwilling, however, to write off ginseng. In China, it's used as a kind of tonic, much like a multivitamin, Dillard explains.
"I'm not sure it's fair to say it has no useful effects just because it was not shown to be effective as a treatment for specific illnesses. Thousands of years of use in Chinese medicine can't be simply ignored, based on these few clinical trials," he says.
The study relied on a systematic review of all published randomized clinical trials, as well as reports from nine recognized experts in the field of alternative medicine and the author's personal database of medical articles.
In addition to the discoveries about ginseng, the study also found the following:
- Gingko biloba: The results of 77 trials involving some 14,000 patients showed this herb was of questionable value for memory loss and tinnitus -- ringing in the ears. However, it can help treat dementia and intermittent claudication, pain in the legs from a lack of blood flow. Side effects include gastrointestinal problems and headache.
- St. John's wort: A total of 57 trials that included nearly 6,000 patients found this herb worked well for mild to moderate depression. However, there can be problems if it's used with other drugs, such as anticoagulants, birth control pills and anti-viral agents.
- Echinacea: Sixteen clinical trials featuring nearly 3,400 patients found it helped prevent upper respiratory infections, although the nature of the studies were such that the findings are still considered inconclusive, says Ernst. People with systemic progressive conditions, such as HIV infection, and autoimmune diseases, such as lupus; multiple sclerosis and tuberculosis, should not take this herb. The study also recommends it not be used for more than eight consecutive weeks.
- Saw palmetto: This one was the clear winner. Eighteen trials featuring nearly 3,000 patients revealed saw palmetto reduced the symptoms of benign prostatic hyperplasia, a non-malignant condition in which the prostate enlarges as a man ages. Side effects can include decreased libido, diarrhea, headache, high blood pressure, nausea and urine retention.
- Kava: Here was another winner. Seven trials, involving 377 patients, found this herb worked as a short-term therapy for anxiety. Side effects can include dizziness, gastrointestinal discomfort and liver disease. It should not be used by children under age 12.
In the final analysis, Ernst says his research demonstrates the need for more rigorous study of all herbal treatments.
Dillard is quick to agree.
"The information we have about many herbal products thus far is good -- some better than others. Still, it is clear that we must accumulate the same kind of clinical trial numbers, including the number of patients, that we find necessary and essential for the approval of traditional medications, including over-the-counter treatments," Dillard says.
What To Do
For more information on how to choose an herbal supplement, visit the American Botanical Council or the Herb Research Foundation.
For a rundown on herbs safe to use during pregnancy, visit GardenGuides.
