Medicinal Plants – Kava

posted by on August 28th 2013


A mature kava shrub, showing the woody stems and distinctive heart-shaped leaves (Starr Environmental)

A mature kava shrub, showing the woody stems and distinctive heart-shaped leaves (Starr Environmental)

Kava or Kava-kava (Piper methysticum) is a species that is indigenous to the south-western Pacific, and can be found throughout Melanesia and Polynesia, as well as parts of Australia. Cultural use of the plant for its sedative properties is widespread throughout the region, particularly in Vanuatu, Hawaii, Fiji, Tonga and Samoa.

Characteristics Of The Kava Plant

Kava is an erect perennial shrub, which grows to a maximum height of around seven metres (although 2-3m is more common). Kava has woody stems, dark green foliage with pale yellow, tiny flowers, and a peppery aroma that is characteristic of species in the Piperaceae family. The leaves are cordate (heart-shaped) and large, growing to 13-20cm in length and reaching similar width.

The tiny flowers appear very rarely, and are unable to produce seed even when hand-pollinated. Instead, the plant reproduces asexually, by means of its rhizomes—underground stems, also known as rootstocks, which grow laterally through the soil, sending down roots and sending up new stems at each internode. It is the rhizomes that are used to make traditional kava preparations, although lower-quality commercial forms may contain other parts of the plant.

Effects Of Kava

The scientific name Piper methysticum literally translates to ‘intoxicating pepper’; it is one of the three most economically important plants in the Piper genus, along with P. nigrum (black pepper) and P. betle (betel). The phytochemicals responsible for the plant’s intoxicating effects are known as kavalactones, and at least eighteen have been identified thus far.

As well as producing a sedative effect, kava rhizome acts as a topical anaesthetic (notably, it numbs the lips and tongue when consumed). Kava also produces a relaxing and mildly euphoric effect, and is often reported to lift depressive moods, induce mental clarity, and render the user more sociable and talkative.

Effects usually commence within thirty minutes of consumption, and last for around 2-3 hours. Stronger doses can last up to eight hours, and some of the more potent cultivars of kava induce effects that can last up to 48 hours.

A bushy specimen growing outside a Hawaiian beachfront kava bar (Joel Abroad)

A bushy specimen growing outside a Hawaiian beachfront kava bar (Joel Abroad)

Distribution & Habitat Of Kava

There are dozens of cultivars of kava—over seventy have been documented so far, although not all are suitable for human consumption. The postulated wild progenitor of kava, Piper wichmannii, is indigenous to northern Vanuatu, and it is believed that kava was first domesticated there—possibly on Pentecost or Maewo Island. Vanuatu is also the world’s largest producer of kava, and is considered its spiritual homeland. It is has listed 28 ‘noble’ cultivars that are of ideal potency and effect; all kava produced for export must be of a listed type.

Genetic testing has demonstrated that there is no distinction between the two species, and that P. methysticum is not strictly a species but rather is a group of sterile cultivars of P. wichmannii. To reflect this, a new taxonomy has been proposed: P. methysticum var. methysticum for the modern cultivars, and P. methysticum var. wichmannii for the wild populations.   

Kava does not respond well to full sunlight, and grows best in well-aerated, well-drained soils that receive over 2,000ml of rainfall per year, in a temperature range of 21-35°C and relative humidity of 70-100%. As wild specimens of the plant are virtually unknown, its distribution is limited to sites to human cultivation; these occur throughout Polynesia, Melanesia, parts of Micronesia, and some parts of Northern Australia.

How Kava Is Cultivated

Kava is generally propagated by breaking up the rhizomes or by removing the offsets (new ‘daughter’ rhizomes) that grow from them. The offsets or rhizome pieces are then potted directly into moist, well-fertilised potting soil.

Alternatively, it can be propagated by using above-ground stem cuttings, which are cut with a sterile blade from young, woody stems and placed directly into soil. Stem cuttings require humid conditions and a temperature range of 20-25°C.

Kava requires plentiful nutrients and loose, well-drained soil to thrive: traditional fertilisers include humus, well-rotted manure and bird guano. Many modern kava growers still practice traditional organic techniques; indeed, the island nation of Vanuatu has laws in place stipulating that all kava produced there must be cultivated organically.

Kava plants must be given sufficient physical space and soil depth to allow the roots to flourish; they must also be watered frequently and abundantly, but never left to stand in water, as this can damage fine root hairs and inhibit growth. As kava plants reach peak concentration of kavalactones after three to four years of growth, plants are typically harvested at this age; however, commercial kava plants may often be cut as early as eighteen months.

Kava rhizomes drying in the sun (Nick Hobgood)

Kava rhizomes drying in the sun (Nick Hobgood)

How Is Kava Prepared?

In the traditional island communities in which kava is found, the fresh rhizomes are typically prepared by pounding, mashing or grinding, with a small amount of water added to the moisture produced by the rhizome itself. The resulting starchy paste is then added to cold water and consumed immediately.

Fresh kava rhizome may also be chewed; with this method, the results are immediate and the numbing effect particularly pronounced. The fresh rhizome is far more potent than its dried counterpart and is more commonly used by traditional communities, although on some islands (particularly Fiji), dried preparations are the norm.

Commercial preparations are usually available in dried, powdered form, although it is also possible to buy frozen fresh rhizome from certain specialist outlets. Many commercial preparations contain parts of the plant other than the rhizomes, such as leaves and stems; it is believed that some of these lower-grade products are responsible for certain health concerns associated with the plant.

Cultural & Traditional Use Of Kava

On every island that kava is cultivated, cultural use has become established, either for spiritual, social or simply recreational purposes. On Vanuatu, kava use in urban areas is primarily social and recreational, and both men and women partake; kava bars are abundant and have been steadily increasing in number since the nation gained independence in 1980. In rural areas, kava use is more ritualised and traditional, is reserved for men, and takes place during the evenings in buildings known as nakamals.

On Fiji, kava is also known as yaqona, and is widely used socially, both by men and women. In social settings, kava use is informal and relaxed; however, more formal rituals are also observed throughout the island. During these ceremonies, cups of pounded kava juice are passed around, and participants are expected to drink the contents of their cup in one swallow. Before drinking, one should clap once; afterwards, three claps are traditional, to signify gratitude.

Villagers from the southernmost Vanuatan island of Anatom preparing kava in the traditional manner (Austronesian Expeditions)

Villagers from the southernmost Vanuatan island of Anatom preparing kava in the traditional manner (Austronesian Expeditions)

Kava And Liver Toxicity

Due to a number of cases of liver damage as a result of consuming commercially-available kava products, several studies into their potential hepatotoxic effect were commissioned. The results led to kava being banned throughout the European Union in 2002, despite the fact that the demonstrated hepatotoxic effect occurred in a tiny number of individuals.

Furthermore, of the 100 documented cases studied, only 14 were considered to be causally linked to kava use, and the majority of the cases were thought to arise from alcohol and other substances used alongside kava. Other cases were thought to be attributable to excessive doses, or from commercial products of dubious provenance (which contained leaf and stem as well as rhizome, and may have consisted of kava cultivars not considered to be ‘noble’). Notably, all cases were associated with dietary supplements containing kava extract obtained via solvent use, and none were associated with kava tea drunk in the traditional manner.

The consensus among many researchers is now that kava may indeed cause liver damage in extremely rare cases, but these cases are so infrequent as to be negligible, and are not justification for a ban. One research team estimated that, based on volume of sales compared to cases of hepatotoxicity in Germany, one potential case of liver damage occurred for every 60-125 million doses of kava consumed.

Legality Of Kava

Based on the results of several later studies that indicated kava’s relative safety, the EU-wide ban was lifted in 2008, although several countries continue to regulate its sale. Poland explicitly prohibits sale or consumption of kava in any form, and the UK has banned medicines containing kava extracts, although kava rhizome itself is not prohibited.

A bowl of traditionally-prepared kava 'tea' (Nate Gray)

A bowl of traditionally-prepared kava ‘tea’ (Nate Gray)

France, Switzerland, the Netherlands and Australia also regulate sale of kava; Canada lifted restrictions on retail sale in February 2012, and the USA does not regulate its use but has issued statements expressing concerns over its safety. Its legal status remains murky in many countries, including the UK.

For this reason, organisations like the Cannabis College in Amsterdam are crucial, as they exist primarily to provide information on the medicinal herbs and plants that are so crucial to humanity yet are systematically subject to propaganda and prohibitionary campaigns. In doing so, more credible and useable information is put into the public domain where it can be accessed and used as part of awareness and legalisation campaigns.

Seshata is a freelance cannabis writer currently based in Amsterdam, Netherlands
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One Comment

  1. Lopini Katoa
    Posted 28/04/2014 at 19:40 | Permalink

    Do you have some list of specific illness that kava cured?

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