Kava or kava-kava (Piper methysticum G. Forst.) is a shrub species belonging to the Piperaceae family.
From a systematic point of view it belongs to:
P. methysticum species.
The terms are synonyms:
– Macropiper methysticum (G.Forst.) Hook. & Arn.;
– Macropiper methysticum Miq.;
– Methysticum methysticum (G.Forst.) Lyons
– Piper wichmannii C.DC..
The term Piper comes from the Greek πέπερι péperi (in Sanskrit píppali): pepper.
The specific epithet methysticum derives from the Latinized Greek methysticum, for intoxicant.
Geographic Distribution and Habitat –
Piper methysticum is a plant native to the northwestern and southwestern Pacific and currently grows on a number of islands in the southern Pacific (Micronesia, Fiji, Hawaii, New Guinea, Samoa, Tonga and Vanuatu), but the specific location of origin.
Its habitat is that of wetlands such as near watercourses, from sea level up to 800 meters.
Kava kava is a sterile, evergreen, highly branched dioecious shrub growing to around 3 – 4.5 meters in height. It produces several stems 1 – 3 cm in diameter which form from a large, thick, woody rhizome.
The plant reproduces only vegetatively, with a highly developed and branched rhizome.
The leaves are broad, heart-shaped, dark green and glossy, and up to just under 40 cm long.
The male plants produce small cylindrical inflorescences, up to 13 cm long, made up of small creamy white flowers, while the female plants rarely flower.
The female flowers, which are particularly rare, do not produce fruit even when hand-pollinated.
Piper methysticum Kava kava is a shrub used as an herb with important ritual and cultural significance in the Pacific Islands, where it is used extensively in social ceremonies and as a means of communication with the gods.
Often harvested from the wild, it is also cultivated, especially in home gardens in the Pacific.
This plant has historically only been grown on the Pacific Islands of Hawaii, the Federated States of Micronesia, Vanuatu, Fiji, Samoa and Tonga. An inventory of the distribution of P. methysticum showed that it was cultivated on numerous islands in Micronesia, Melanesia, Polynesia and Hawaii, while specimens of P. wichmannii all came from Papua New Guinea, the Solomon Islands and Vanuatu.
The plant is commonly sold in local markets and is also exported to Europe, America, etc., where it is used medicinally.
For its cultivation it should be remembered that it is a plant of the humid and lowland tropics, where it is found at altitudes of up to 800 meters. It grows best in areas where annual daytime temperatures are between 22-35°C, but can tolerate 14-40°C.
It prefers an average annual rainfall between 2,200 and 4,000 mm, but tolerates between 1,800 and 5,000 mm.
It prefers a shady location when young, although older plants are more tolerant of sunny locations.
From the pedological point of view it prefers a well-drained, stony soil with abundant water but grows in most soils of at least moderate fertility, with a pH in the range 5.5 – 6.5, tolerating 5 – 7; it also requires a sheltered position from strong winds and is a slow growing plant.
This shrub can be grown in containers that are overwintered indoors from fall to spring.
At the age of 10 months the average root weight is about 1 kilo per plant.
The crop is potentially profitable if harvested after 3 – 4 years.
The life span of the plant can be 15 – 30 years.
Propagation occurs both by seed and by semi-mature wood cuttings.
Kava consists of sterile cultivars cloned from its wild ancestor (Piper wichmanii). Today it includes hundreds of different cultivars grown throughout the Pacific. Each cultivar not only has different requirements for successful cultivation, but also displays unique characteristics both in terms of appearance and in terms of psychoactive properties.
So in recent years, government regulatory bodies and non-profit NGOs have been set up with the stated purpose of monitoring kava quality, producing regular reports, certifying vendors selling noble and proper kava, and warning customers against products which may contain tudei varieties.
Customs and Traditions –
Piper methysticum common name kava(-kava) which derives from the languages of the area of origin of the plant, Tongan and Marquesan, which means bitter.
Other names for this plant are: awa (Hawaii), ava (Samoa), yaqona or yagona (Fiji), sakau (Pohnpei), seka (Kosrae), and malok or malogu (parts of Vanuatu).
Kava is consumed for its sedative effects throughout the Pacific Ocean cultures of Polynesia, including Hawaii and Vanuatu, Melanesia, some parts of Micronesia, such as Pohnpei and Kosrae, and the Philippines.
In the world, the term kava is used to refer not only to the plant, but also to the dried roots and rhizomes marketed as supplements, and to the drink whose consumption is widespread among the populations of Polynesia (including the Hawaiian Islands), Melanesia, Micronesia, as well as Australia.
The roots have a long history of use in the South Pacific islands for some herbal/medicinal preparations, including a sedative drink called kava that is now sold commercially in bottles. Kava is a cash crop in Vanuatu and Fiji. The drink is consumed to promote relaxation and relieve stress without interfering with alert mental functioning. It is also taken as a sacrament before ceremonies or in the spirit of friendship during social gatherings.
The active ingredients of kava are phenylpropane derivatives called kavalactones, among which at least 18 have been identified, of which at least 15 are psychoactive. Only six, however, produce significant effects and their relative concentration can vary according to the variety and production methods, generating different effects; they also possess sedative and anesthetic properties.
In addition to these substances, the main components responsible for the psychoactive action of the extracts are kawainaa, diidrokavainaa, methysticin, dihydromyristicin, yangonina and desmethoxyangonin. These alone are responsible for 96% of the plant’s pharmacological action. Minor components are flavocaine, chalcones and components responsible for the toxic activity but not present in the roots, such as pipermethystine and other alkaloids.
From the root of the plant a drink is obtained with sedative, anesthetic and euphoric properties. A systematic review conducted by the British non-profit Cochrane concluded that it was likely to be more effective than placebo in treating anxiety in the short term.
According to the World Health Organization, moderate consumption of kava in its traditional form, i.e. as an aqueous suspension of kava roots, presents an “acceptably low level of health risk.” However, consuming kava extracts made with organic solvents or excessive amounts of poor-quality kava products may be linked to an increased risk of adverse health outcomes, including potential liver damage.
As regards the therapeutic activity of this plant it is due to the following biological activities:
– Enhancement of GABA receptor activity (by kawain, dihydrokavain, methysticin, dihydromyristicin and yangonine), similar to benzodiazepines.
– Inhibition of the reuptake of norepinephrine (by kawaine and methysticin) and probably of dopamine (by kawaine and desmethoxyyangonine), which could have an antidepressant effect.
– Binding to the CB1 cannabinoid receptor (by yangonin).
– Inhibition of voltage-gated sodium channels and voltage-gated potassium channels (by kawain and methysticin).
– Inhibition of MAO-B (by the 6 major kavalactones).
The binding with the GABA receptor could be responsible for the anxiolytic and sedative properties, similar to some anxiolytics, while the increase of dopamine in the nucleus accumbens due to the inhibition of its reuptake and MAO-B could be responsible for the slightly stimulating properties that counteract sedative ones. Furthermore, the inhibition of MAO-B could have protective effects on the central nervous system. The inhibition of voltage-dependent channels is the basis of the anxiolytic and mood stabilizing effect of some drugs. It also induces effects on the serotonin system responsible for improving sleep quality.
The balanced set of these actions overall generates an anxiolytic and slightly sedative action, without, however, generating marked effects on cognitive abilities and the typical stunning instead of benzodiazepine sedatives (such as diazepam and alprazolam).
With reference to the consumption of Piper methysticum, it is taken in the form of root infusions or dried extracts, which can also be contained in capsules. The effects depend on the variety consumed, method of preparation, age of the plant and method of consumption. In general, it can be said that the noblest species produce a state of relaxation, anxiolytic and well-being without diminishing cognitive abilities.
Its anxiolytic power has been found to be comparable to that of benzodiazepines. Unlike these, however, it does not induce phenomena of addiction and tolerance. The roots of the plant are commonly used to produce extracts with anxiolytic, relaxing and pain-relieving effects and this has promoted its discovery in the Western world as a phytotherapic for anxiety states and insomnia.
Particular attention has been paid to its possible hepatotoxicity and this has had wide coverage in the media. However, the World Health Organization states that moderate consumption of aqueous extracts of Kava roots, produced with adequate quality standards, does not present particular health risks. Risks could instead exist when low quality extracts containing other parts of the plant, in addition to the roots, produced with organic solvents and which contain an excessive amount of potentially toxic compounds are consumed.
As a precaution, in some countries, the competent ministries have banned the sale of homeopathic products based on Kava. However, the purchase and possession of products based on this plant is not illegal.
Among the edible uses, it should be remembered that the roots and stems are the source of a stimulating alkaloid drink called kawa which, as mentioned, is widely consumed in some Polynesian islands.
Of the medicinal effects, the root is a bitter, very pungent, warming herb with a lilac aroma. It has a warm, aromatic and bitter taste that leaves the mouth slightly numb.
It is diuretic, relieves pain, relaxes spasms and has a stimulating effect on the circulatory and nervous systems. It is calming and stimulating in low doses, high doses cause intoxication and euphoria.
The root also has a reputation as an aphrodisiac.
It is taken internally in the treatment of genitourinary infections, gallbladder disorders, arthritis and rheumatism.
The scrapings of the root bark are chewed to soothe sore throats and toothaches.
Externally, the root is used to relieve joint pain.
In Fiji, seizures and stiffness in children are treated with liquid squeezed from the leaves.
The leaves are chewed as a treatment for bronchitis.
Externally, however, they are rubbed on centipede bites, insect bites and poisonous fish bites.
The branches are used as a remedy for sore throats.
An infusion of the leaves is smeared on some inflammations and is used to treat watery vaginal discharge.
Method of Preparation –
Various parts of the Piper methysticum plant are used, some for food purposes, such as the production of beverages and others for various medicinal or religious purposes.
The roots are harvested as needed and can be used fresh or dried.
To prepare the drink, the parts of the plant are pulverized by grinding or chewing, suspended in water and then sieved to remove the residue. The resulting milky liquid is the drink.
Kava is consumed in a variety of ways in the Pacific Ocean cultures of Polynesia, Vanuatu, Melanesia, and parts of Micronesia and Australia. Traditionally, it is prepared by chewing, grinding or pounding the roots of the plant. The grinding is done by hand against a conical block of dead coral; the hand forms a mortar and the coral a pestle. The ground root/bark is only combined with a little water, as the fresh root releases moisture during grinding. Hammering is done in a large stone with a small log. The product is then added to cold water and consumed as quickly as possible.
The extract is an emulsion of kavalactone droplets in starch and buttermilk. The flavor is slightly pungent, while the characteristic aroma depends on whether it was prepared from a dry or fresh plant and on the variety. The color ranges from gray to light brown to dull 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 makes a stronger drink than dried kava. The strength also depends on the species and cultivation techniques.
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 more quickly into the bloodstream. Traditionally, no flavoring is added.
In Papua New Guinea, locals in Madang Province refer to their kava as waild koniak (“wild cognac” in English).
Fijians commonly share a drink called grog made by pounding sun-dried kava root into a fine powder, straining it, and mixing it with cold water. Traditionally, grog is drunk from the cut half shell of a coconut, called a bilo. Grog is very popular in Fiji, especially among young people, and often brings people together for storytelling and socialising. Drinking grog for a few hours brings a numbing and relaxing effect to the drinker; Grog also numbs the tongue, and grog consumption is typically followed by a “hunter” or sweet or spicy snack to follow a bilo.
However, it should be remembered that an excess of intake of the root can cause amazement.
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.
Attention: The pharmaceutical applications and alimurgical uses are indicated for informational purposes only, they do not in any way represent a medical prescription; we therefore decline all responsibility for their use for curative, aesthetic or food purposes.