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 effective as benzodiazepine drugs. The lack of significant differences in HAM-A scores is probably more a sign of the relative coarseness of the rating scale than truly equal efficacy. Kava is a tall shrub that grows in the islands of the Pacific Ocean. In Fiji, the plant is called “yaquona,” in Hawaii, it’s known as “awaj,” and in Aboriginal tribes, it’s referred to as “grog.
” This shrub produces large, green, heart shaped leaves that grow thickly on the branches. Long, slender flowers grow where the branches meet the stems. The roots look like bundles of woody, hairy branches. The root is the part of the plant used medicinally. The use of herbs is a time honored approach to strengthening the body and treating disease. Herbs, however, contain components that can trigger side effects and interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider qualified in the field of botanical medicine.
This is particularly true for kava, because there is evidence it may cause liver damage. Reports in the United States and Europe have linked kava with severe liver problems. Kava containing products have been associated with at least 25 reports of liver related injuries (including hepatitis, cirrhosis, liver failure, and death). In one case report, a 50 year old man developed hepatitis after taking 3 – 4 kava extracts daily for 2 months. His condition quickly deteriorated, and he needed a liver transplant. We don’t know much about kava’s effect on the liver.
It may be that the kava supplements some people took were contaminated with other substances that caused liver damage. Or it is possible that some people already had liver problems before taking kava, or that they took a combination of kava and other prescription medications or herbs that damaged their livers. It is also possible that the doses generally recommended for kava affect people differently, so that a dose that would cause liver damage in one person might have no effect on the liver in another person.
Because of the uncertainty around kava, you should take it only with your doctor’s supervision. If you have taken kava and are having symptoms of liver damage [such as yellow skin (jaundice), fatigue, abdominal pain, loss of appetite, nausea, vomiting, and joint pain], seek immediate medical attention. Do not take kava if you have depression, liver disease, such as hepatitis, or Parkinson’s disease. Pregnant or breastfeeding women should not take kava. Do not take kava if you are going to have surgery (and tell your surgeon if you have taken it in the past).
Kava can prolong the effect of anesthesia. Do not drink alcohol while taking kava. Other side effects associated with kava include allergic skin reactions (such as contact dermatitis), dizziness, drowsiness, restlessness, stomach upset, and tremors. Long-term use at high doses may cause flaky, dry, and yellowish discoloration of the skin, hair loss (alopecia), partial loss of hearing, and loss of appetite. Like alcohol, kava may have intoxicating effects and should not be taken before operating a car or other machinery.