Kava (Piper methysticum) (Piper Latin for "pepper", methysticum Greek for "intoxicating") is an ancient crop of the western Pacific. Other names for kava include awa (Hawaii), 'ava (Samoa), yaqona (Fiji), and sakau (Pohnpei). The word kava is used to refer both to the plant and the beverage produced from its roots. Kava is a tranquilizer primarily consumed to relax without disrupting mental clarity. Its active ingredients are called kavalactones. In some parts of the Western World, kava extract is marketed as herbal medicine against stress, insomnia, and anxiety.
The extract is an emulsion of kavalactone droplets in starch. The taste is slightly pungent, while the distinctive aroma depends on whether it was prepared from dry or fresh plant, and on the variety. The colour is grey to tan to opaque greenish.
Kava prepared as described above is much more potent than processed kava. Chewing produces the strongest effect because it produces the finest particles. Fresh, undried kava produces a stronger beverage than dry kava. The strength also depends on the species and techniques of cultivation. Many find mixing powdered kava with hot water makes the drink stronger.
In Vanuatu, a strong kava drink is normally followed by a hot meal or tea. The meal traditionally follows some time after the drink so that the psychoactives are absorbed into the bloodstream quicker. Traditionally no flavoring is added.
Fijians commonly share a drink called "grog", made by pounding sun-dried kava root into a fine powder and mixing it with cold water. Traditionally, grog is drunk from the shorn half-shell of a coconut, called a "bilo." Despite tasting very much like dirty water, grog is very popular in Fiji, especially among young men, and often brings people together for storytelling and socializing.
Desmethoxyyangonin, one of the six major kavalactones, is a reversible MAO-B inhibitor (Ki 280 nM) and is able to increase dopamine levels in the nucleus accumbens. This finding might correspond to the slightly euphoric action of kava.
Kavain in both enantiomeric forms inhibit the reuptake of noradrenalin at the transporter (NAT), but not of serotonin (SERT). An elevated extracellular NA level in the brain may account for the reported enhancement of attention and focus.
A moderately potent kava drink causes effects within 20–30 minutes that last for about two and a half hours, but can be felt for up to eight hours. Because of this, it is recommended to space out servings about fifteen minutes apart. Some report longer term effects up to two days after ingestion, including mental clarity, patience, and an ease of acceptance. The effects of kava are most often compared to alcohol, or a large dose of Valium.
The sensations, in order of appearance, are slight tongue and lip numbing (the lips and skin surrounding may appear unusually pale); mildly talkative and sociable behavior; clear thinking; anxiolytic (calming) effects; relaxed muscles; and a very euphoric sense of well-being. The numbing of the mouth is caused by the two kavalactones kavain and dihydrokavain which cause the contraction of the blood vessels in these areas acting as a local topical anesthetic. These anesthetics can also make one's stomach feel numb. Sometimes this feeling has been mistaken for nausea. Some report that caffeine, consumed in moderation in conjunction with kava can significantly increase mental alertness.
A potent drink results in a faster onset with a lack of stimulation, the user's eyes become sensitive to light, they soon become somnolent and then have deep, dreamless sleep within 30 minutes. Sleep is often restful and there are pronounced periods of sleepiness correlating to the amount and potency of kava consumed. Unlike alcohol-induced sleep, after wakening the drinker does not experience any mental or physical after effects. However, this sleep has been reported as extremely restful and the user often wakes up more stimulated than he or she normally would. Although excessive consumption of exceptionally potent brew has been known to cause pronounced sleepiness into the next day. Although heavy doses can cause deep dreamless sleep, it is reported that many people experience lighter sleep and rather vivid dreams after drinking moderate amounts of kava.
After thousands of years of use by the Polynesians and decades of research in Europe and the U.S., the traditional use of kava root has never been found to have any addictive or permanent adverse effects. Users do not develop a tolerance. While small doses of kava have been shown to slightly improve memory and cognition, large amounts at one time have been shown to cause intoxication. In Utah, California, and Hawaii there have been cases where people were charged with driving under the influence of alcohol after drinking a significant amount of kava (eight cups or more) although some of them were acquitted due to the laws not being broad enough to cover kava consumption.
Kava is used for medicinal, religious, political, cultural and social purposes throughout the Pacific. These cultures have a great respect for the plant and place a high importance on it. Correspondingly, the paraphernalia surrounding the traditional kava ceremony are expertly crafted. Traditionally designed kava bowls are bowls made from a single piece of wood, with multiple legs. More modern examples are also highly decorated, often carved and inlayed with mother of pearl and shell.
Kava is used primarily at social gatherings to increase amiability and to relax after work. It has great religious significance, being used to obtain inspiration. Among some fundamentalist Christian sects in the Western Pacific, the drink has been demonized and seen as a vice, and young members of these religions often reject its traditional use. However, among most mainline Christian denominations, i.e. the Roman Catholic, Methodist, and Anglican churches, kava drinking is encouraged where it replaces the greater danger of alcohol.
The kava shrub thrives in loose, well-drained soils where plenty of air reaches the roots. It grows naturally where rainfall is plentiful (over 2,000 mm/yr). Ideal growing conditions are 20 to 35 degrees Celsius (70 to 95 °F), and 70–100% relative humidity. Too much sunlight is harmful, especially in early growth, so kava is an understory crop.
Kava cannot reproduce sexually. Female flowers are especially rare and do not produce fruit even when hand-pollinated. Its propagation is entirely due to human efforts by the method of striking.
Traditionally, plants are harvested around 4 years of age, as older plants have higher concentrations of kavalactones. But in the past two decades farmers have been harvesting younger and younger plants, as young as 18 months. After reaching about 2 m height, plants grow a wider stalk and additional stalks, but not much taller. The roots can reach 60 cm depth.
In Vanautu there are strict laws over the exportation of Kava. Only strains they deem as "noble" varieties that are not too weak or too potent are allowed to be exported. Only the most desirable strains for every day drinking are selected to be noble varieties in order to maintain quality control. In addition their laws mandate that exported kava must be at least five years old and farmed organically. Their most popular noble strains are "Borogu" from Pentecost Island. "Melomelo" from Ambae island, (called 'sese' in North Pentecost) and "Palarasul" kava from Espiritu Santo Island. In Vanuatu, Tudei (two-days) kava is reserved for special ceremonial occasions and exporting it is not allowed. "Palisi" is a popular Tudei variety.
In Hawaii there are many other strains of kava. Some of the most popular strains are the "Mahakea," "Mo'i," and "Nene" varieties. The Ali'i (kings) of old Hawaii coveted the special kava they called "Mo'i" that had a strong cerebral effect due to a predominant amount of the kavalactone kavain. This sacred variety was so important to them that no one but royalty could ever experience it, "lest they suffer an untimely death."
Other strains are found in Fiji, Tonga, and Samoa.
The mature roots of the kava plant are harvested after a minimum of 4 years (at least five years ideally) for peak kavalactone content. Most kava plants produce around 50 kgs (110 lbs) of root when they are harvested. Kava root is classified into two categories: crown root (or chips) and lateral root. Crown roots are the large diameter pieces that look like big (1.5 inch to 5 inches diameter) wooden poker chips. Most kava plants consist of approximately 80% crown root upon harvesting. Lateral roots are smaller diameter roots that look more like a typical root. A mature kava plant is approximately 20% lateral roots. Kava lateral roots have the highest content of kavalactones in the kava plant. "Waka" grade kava is kava that is made of lateral roots only.
Fiji Kava Council Chairman Ratu Josateki Nawalowalo welcomed the findings, saying that they would boost the kava industry. For his part, Agriculture Minister Ilaitia Tuisese called on the researchers to help persuade members of European Union to lift their ban on kava imports.
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, Germany and The Netherlands. 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 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). The Australian Therapeutic Goods Administration has recommended that no more than 250 mg of kavalactones be taken in a 24 hour period. 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.
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 and in vivo. 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), (73 mg/kg, 3 months).
Flavokavain B, found in the plant's rhizome (large horizontal underground stem), may also contribute to toxic effects. And, it is known that some of the kavapyrones block several subtypes of the enzyme cytochrome P450, 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 determined that the high concentrations of kava resins in pill form extracts alone could have been the culprit for the liver damage incidents.
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. However, kava extracts in pill form will not have the glutathione in it to help protect the liver.