Facts About Kava

In 2002 and 2003, Germany and the United Kingdom, respectively, banned the sale of kava due to increasing concerns about liver damage. Other countries have since banned it. Mixed research data exists surrounding kava and reports of liver toxicity, says Professor Edzard Ernst, of Peninsula Medical School at the Universities of Exeter and Plymouth in the U.K., in the October 2007 issue of the "British Journal of Clinical Pharmacology." Apparently liver damage due to kava consumption has not been a concern among people in the South Pacific, in spite of its use for generations. Ernst notes the idea of possible contamination of the kava root with different parts of the plant as being one possible cause of toxicity. Furthermore, he says, there were growing arguments about the safety of the traditional water-based kava extracts versus the newer solvent-based ones.
There are few effectiveness comparison studies on kava. What we do have are covered here. Note that they all compare kava with the benzodiazepine group of drugs, particularly oxazepam.
Two studies comparing kava with benzodiazepines, oxazepam and bromazepam, showed that there was no different in the effects. One 1990 placebo-controlled, double-blind clinical trial compared kavain with oxazepam in 38 out-patients diagnosed with anxiety associated with neurotic or psychosomatic disturbances. The anti-anxiety effectiveness of the two preparations was assessed by the Anxiety Status Inventory (ASI) and the Self-Rating Anxiety Scale (SAS) of Zung. The substances proved to be equivalent in the potency and nature of their effects, with no adverse reactions from either group.
Another 1993 double-blind study followed 174 patients with anxiety symptoms for a period of six weeks . Patients received either 300mg of a 70% kavalactone extract daily, 15mg/day of oxazepam or 9mg/day bromazepam. Improvement in HAM-A scores was roughly equivalent between groups. Nonetheless, few clinicians would agree that kava is equally