Blumenthal emphasized that the information now coming together on kava needs to be scientifically evaluated and addressed. And he noted this is being done by the FDA and the trade associations and that "These considerations and cautions represent a prudent approach to the information presently available".

Jerry Cott, PhD., former Chief of the Psychopharmacology Research Program at the National Institute of Mental Health said, "If the incidence of liver toxicity for kava is correct, then according to German researchers it is very similar to that of conventional pharmaceutical anti-anxiety and antidepressant prescription drugs. These are generally considered to be acceptable (though small) risks," he said, referring to the risk-benefit comparison by which conventional medicines are evaluated.

Cott also pointed out that a small clinical study from Duke University published in October showed no adverse effects from kava on the liver.

In 1990 the German government's Commission E, a panel of herbal experts in the fields of medicine and pharmacy, evaluated the scientific and medical literature and had approved the use of kava as a nonprescription medicine for "nervous anxiety, stress, and restlessness". The safe and effective benefits of kava to relieve symptoms of anxiety were supported last year in a meta-analysis, a systematic statistical review of seven human clinical trials published in the Journal of Clinical Psychopharmacology and again in a similar critical review this year. The reviews did not find adverse effects related to liver toxicity.

Traditionally served as a beverage in social or ceremonial ritual in island communities of the south Pacific, kava (also known as kava kava, Piper methysticum) has been revered as the primary herb in these cultures (e.g., Fiji, Vanuatu, Samoa, Tonga) for possibly two or three millennia. Kava use in these cultures has been considered generally safe, with few adverse side effects.

"Historically, the scientific literature does not show much basis for concern about potential liver toxicity. These cases in Europe are relatively recent," said Blumenthal who is also an associate professor at the College of Pharmacy at the University of Texas at Austin.

The primary adverse effects of kava reported in the literature are relatively minor and are usually associated with highly excessive intake. These effects include the occasional yellowing and scaling of skin, which returns to normal after discontinuation of the herb. Other effects associated with high doses include slow adjustments of the eyes to changes in light and impaired motor control (related to kava's action of relaxing skeletal muscles, one of the reasons it is used for treating mild cases of anxiety).

Currently, kava ranks ninth in sales of all herbal dietary supplements sold in mainstream retail markets, with total mainstream sales in 2000 of approximately $15 million. This statistic does not include sales in health food stores, multi-level marketing companies, mail order, or sales by health professionals, which could account for an additional $15 million, or possibly more.

The American Botanical Council is the nation's leading non-profit organization dealing with research and educational issues regarding herbs and medicinal plants. The 13-year-old organization occupies a 2.5 acre site in Austin, Texas where it publishes HerbalGram, a peer-reviewed journal on herbal medicine and other educational materials for consumers and healthcare professionals, including the highly rated The Complete German Commission E Monographs - Therapeutic Guide for Herbal Medicines (1998). Its new publication for health professionals, The ABC Clinical Guide to Herbs, will be published in spring 2002. Information contact: ABC at PO Box 144345, Austin, TX 78714-4345, ph: 512-926-4900, fx: 512-926-2345. Website: www.herbalgram.org.