On Kava (from Wiki):
Side Effects and Safety
Skin Rashes
Chronic and heavy use of kava for a period of three months or more has occasionally been reported to cause a scaly, yellow skin rash and eye irritation that disappears after discontinuation of the herb. The rash resembles one brought on by a niacin (Vitamin B3) deficiency; however, a double-blind, placebo-controlled study showed no change in the rash after niacin supplementation. The 29 Tonga islanders who presented with the rash after heavy kava consumption--more than 900 g/week--were given either 100 mg of oral niacinamide or placebo. No statistically significant improvement was seen in the supplementing group, suggesting niacin deficiency may not cause the rash, which is more characteristic of an acquired ichthyosis. Until more is known, however, people taking kava regularly may also wish to take a multivitamin with at least 50 to 100 mg of niacin daily.
Liver damage incidents and regulation
In the year 2001 concerns were raised about the safety of commercial kava products.[7] There have been allegations of severe liver toxicity, including liver failure in some people who had used dietary supplements containing kava extract (but not in anyone who had drank kava the traditional way). Out of the 50 people worldwide taking kava pills and extracts that have had some type of problem, almost all of them had been mixing them with alcohol and pills that could have effects on the liver. The fact that different kava strains have slightly different chemical composition made testing for toxicity difficult as well.
The possibility of liver damage consequently prompted action of many regulatory agencies in European countries where the legal precautionary principle so mandated. In the UK, the Medicines for Human Use (Kava-kava) (Prohibition) Order 2002 prohibits the sale, supply or import of most derivative medicinal products. Kava is banned in Switzerland, France and The Netherlands[citation needed]. The health agency of Canada issued a stop-sale order for kava in 2002. But legislation in 2004 made the legal status of kava uncertain. The United States CDC has released a report[8] expressing reservations about the use of kava and its possibly adverse side effects (specifically severe liver toxicity), as has the Food and Drug Administration (FDA).[9] The Australian Therapeutic Goods Administration has recommended that no more than 250 mg of kavalactones be taken in a 24 hour period.[10] According to the Medicines Control Agency in the U.K., there is no safe dose of kava, as there is no way to predict which individuals would have adverse reactions.[11]
Toxicology of pill form kava extracts with stems and leaves
Piperidine alkaloids from the kava plant
Piperidine alkaloids from the kava plant
The legal intervention of several countries stimulated research, and hepatotoxic substances were found in the stems and leaves of the plant. Researchers from the University of Hawaii at Manoa found that an alkaloid called pipermethystine (formula 1), contained in stem peelings and leaves but not in the roots, had toxic effects on liver cells in vitro[12] and in vivo.[13] In rats fed with 10 mg/kg pipermethystine for two weeks, indications of hepatic toxicity were found. Comparable signs of toxicity were not detected with kava rhizome extracts (100 mg/kg, 2 weeks)[13], (73 mg/kg, 3 months).[14]
Flavokavain B, found in the plant's rhizome (large horizontal underground stem), may also contribute to toxic effects.[15] And, it is known that some of the kavapyrones block several subtypes of the enzyme cytochrome P450[16], which can result in adverse interactions with other drugs used concomitantly.
Hawaiian researchers learned from a trader in Fijian kava that European pharmaceutical companies eagerly bought up the stem and leaves peelings when demand for kava extract soared in Europe in 2000 and 2001. Before 2002, substantial amounts of aerial parts of the kava plant were being exported to North America and Europe and obviously used for the production of commercial pill extracts. For traditional use in the South Pacific, stem peelings and leaves are discarded, and only the rhizomes are used and extracted with water. This may explain why native populations that make heavy use of kava experience side effects that are mild, temporary, and confined to the skin, whereas industrialized countries that have newly adopted kava occasionally show severe, acute responses.
A medical conference in Fiji and determined that the high concentrations of kava resins in pill form extracts alone could have been the culprit for the liver damage incidents.
Toxicity of traditional kava beverage preparations
Kava has been consumed heavily as a beverage in the south Pacific for around 3000 years with no reports of liver problems. One study has reported that when kava preparations are made with the root of the plant no toxicity is found.[17] However, in one study some changes in liver function are noticed. The effects are temporary and reversible when discontinuing kava use.[18] Although kava root does not cause liver toxicity, there is evidence of health concerns among heavy drinkers, including poor nutrition and a rise in liver enzymes.[19]
The plant also contains glutathione. In extracts its concentration varies depending on the lipophilicity of the applied solvent; the amount is higher in aqueous extracts. Glutathione in kava beverage preparations is able to provide a certain protection of liver cells.[20] However, kava extracts in pill form will not have the glutathione in it to help protect the liver.
Allergy
Literature suggests that less than one half of one percent of people that take kava have an allergic reaction to it. Allergic reactions are usually mild and include itchy skin or itchy throat, and hives on the skin usually prevalent on the user's belly region. If someone has an allergy to any relative of the pepper family, such as black pepper, they have a higher chance of having a kava allergy.
Edited by Rags847, 04 February 2008 - 07:37 AM.
