| BOTANICAL
NAME Piper methysticum Back to Top
PART USED The rhizome
COMMON USES Anxiety and conditions of tension and restlessness
ACTIVE CONSTITUENTS Kava lactones (also known as kava -pyrones)
HOW IT WORKS Kava exerts a relaxing effect on the central nervous system. Kava is noted
for promoting relaxation without loss of mental sharpness. This makes it particularly
useful for daytime management of anxiety. Kava also promotes normal, restful sleep, and
exerts a mild, relaxing effect on skeletal muscles.
RECOMMENDED USE Standardized extract containing 70 percent kava lactones, 100 milligrams
two to three times daily (equivalent to 140 to 210 milligrams of kava lactones daily).
SIDE EFFECTS At the therapeutic dosage just given, the only reported side effects are mild
gastrointestinal disturbances. Long-term consumption may turn the skin yellow temporarily.
If this occurs, you should stop taking kava. In rare cases, an allergic skin reaction
(rash) may occur.
The intake of large quantities of nonstandardized kava. liquid preparations can lead to a
dry, scaly skin rash known as "kava dermopathy." Problems with equilibrium (body
balance) have also been reported. Risk of this rash or equilibrium problems occurs only at
kava lactone dosages in excess of several grams daily.
SAFETY ISSUES Kava is not recommended for use by pregnant or lactating women. The German
Commission E monograph on kava also warns against using it with barbiturates,
antidepressants, or other substances that may act on the central nervous system.
ALTHOUGH its name could easily be
mistaken for a brand of instant coffee, kava-kava is actually a Polynesian and Melanesian
herb that has emerged as an effective alternative to drugs commonly prescribed for
anxiety. Along with valerian root extracts, kava root extracts in Europe have become an
herbal alternative to antianxiety medications such as Xanax and Valium. Kava reduces
anxiety and promotes a relaxed, sociable state and heightened mental acuity. Best of all,
kava extracts are not associated with the side effects and addictive properties common to
prescription antianxiety drugs.
PLANT FACTS
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Kava-kava (Piper methysticum) is a
member of the pepper family, and is native to many islands of the Pacific. The plant is a
robust perennial shrub that thrives at elevations of 500 to 1,000 feet above sea level. It
grows best in stony ground and likes good sun exposure. Although it can reach heights of
20 feet, it is usually harvested at about 7 to 8 feet.1 Modem herbal
preparations of kava primarily use the rhizome or root stock for extraction.
The plant appears to have originated in Papua New Guinea-Indonesia and then spread to
other islands through trade and by explorers.2 For a complete overview of plant
origins, traditional use of kava, and its chemical constituents, I highly recommend a book
by Vincent Lebot, Mark Merlin, and Lamont Lindstrom entitled Kava: The Pacific Drug (Yale
University Press, 1992).
HISTORY (CHEWIN', SPITTIN', DRINKIN',
AND CHILLIN')
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The incredible history of kava and its use
in traditional ceremonies of the Pacific islands have been the subject of many lengthy
anthropological reports and textbooks.
Introduction of kava to the modem world is attributed to a botanist and artist who
accompanied Captain James Cook on his first voyage in the Endeavor (1768-1771). Daniel
Scholander and Sydney Parkinson are given credit for being the first to describe the plant
and its use as an intoxicating drink. The actual botanical name, Piper methysticum, was
coined by Johann Georg Forster to describe an intoxicating pepper drink.3
A nonalcoholic drink made from the root of kava played an important role in a variety of
ceremonies in the Pacific islands. The kava ceremonies were a key event to welcome
visiting royalty or highly honored guests. it was also a part of smaller meetings among
village elders. Less formal kava drinking was a common part of many social gatherings.
The manner of preparation of the kava beverage probably horrified a few of the European
explorers. After the root is scraped, designated "chewers" chew cut pieces of
the root and spit the macerated root into a bowl. Coconut milk was then added and the
mixture strained and decanted to another bowl.4
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Today, the traditional chewing has largely
been replaced by pounding or grating of the root. Special bowls and utensils are used in
the ceremony. The kava. beverage is placed in a cup by a designated person who, in turn,
delivers it to the special guest. The whole cup must be chugged without stopping! The
audience claps three times and shouts Maca ("It is empty"). Others can then be
served.
Although the ceremony has been altered and even outlawed on some islands, it continues
elsewhere today. Rumor has it that Hillary Clinton took part in a kava ceremony held in
her honor by a Samoan community on the Hawaiian island of Oahu.5 Whether she's
continued the ceremony during meetings with Newt Gingrich and his mother is open to
speculation.
So, how do people feel when they drink kava? The drink initially causes the mouth to numb.
This is followed by a mellow and tranquil state that encourages socializing. As long as
the mixture is not too strong, the kava drinker usually attains a state of contentment and
often enjoys a greater sense of well-being. Along with relaxation, many people experience
sharper mental acuity, improved memory, and heightened sense awareness.6
Excessive consumption can lead to muscle weakness and dizziness. As we'll note later,
long-term, excessive use can also lead to a skin rash that will leave one feeling anything
but sociable.
MEDICALLY ACTIVE
CONSTITUENTS
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The search for kava's active
constituents spans 130 years. The initial monograph on the chemical components and
pharmacological activity of kava was written and published by the pharmacologist Louis
Lewin in 1886.
Repeating work that had originally been published in 1860 and 1861, Lewin traced the
relaxing properties of kava to a group of constituents in the root and rhizome.7 These
and other compounds discovered later would eventually be called kava lactones. The
collective action of these constituents is responsible for kava's antianxiety effects.8
The kava lactones, sometimes referred to as kava pyrones, have become the focal point of
modern kava extracts. These compounds are found in the fat-soluble portion of the root and
rhizome. Good-quality kava rhizome contains between 5.5 and 8.3 percent kava lactones.9
The standard phytopharmaceutical preparation used in clinical research in Europe contains
70 percent kava lactones.
HOW KAVA WORKS
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In animal studies, kava lactones have
shown antianxiety, analgesic (pain relieving), muscle-relaxing, and anticonvulsant
effects.10 Kava's mode of action on the nervous system appears to differ from
that of many sedative and muscle relaxants. Benzodiazepine-based drugs such as Xanax and
Valium act by binding to or "turning on" specific receptors in the brain known
as GABA receptors. By binding these receptors, these drugs promote sedation. Valerian root
weakly binds similar receptors, partially explaining its actions as a sedative and
antianxiety herbal medicine.
Kava lactones appear to be less selective.11 Studies suggest that kava directly
influences the limbic system-the ancient part of the brain associated with emotions and
other brain activities.12 This may partly explain why kava's antianxiety
effects seem to extend beyond psychological processes to include muscle relaxation as
well. Animal studies also indicate that kava has pain-reducing capabilities.13
Kava does not reduce pain by the same pathway as that used by opiate analgesics. Kava is
rarely prescribed by modern herbalists to reduce pain, but it has been used extensively
for this purpose by native medicine men of the Pacific islands. Kava lactones also have
anticonvulsive properties and seem to protect the brain during times of ischemia (reduced
blood flow leading to low oxygen supply).14,15 A major focus of current
research on kava lactones is in the treatment of epilepsy. While this certainly has
exciting ramifications, it is too early to begin recommending kava extracts for the
primary treatment of epilepsy.
HEALTH CARE APPLICATIONS
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One of the primary uses for kava is
in the treatment of anxiety and nervous tension. It creates changes in brain activity (as
measured by electroencephalogram, or EEG) typical of antianxiety drugs but without their
sedative and hypnotic effects.16,17 Paradoxically, people taking kava
show increased attentiveness and concentration while feeling relaxed! This is a remarkable
effect for an antianxiety treatment to possess and really places kava in a class all its
own.
In head-to-head studies with benzodiazepine-based drugs, kava has fared wonderfully. One
study18 showed that volunteers improved in terms of reaction time and
performance on a word recognition test while taking kava. Volunteers taking oxazepam
(Serax), a benzodiazepine drug, did not do as well as those taking kava.
How about the treatment of anxiety? One study measured the effect of 100 milligrams of a
kava extract (containing 70 percent kava lactones) administered three times daily for 4
weeks against placebo. Fifty-eight patients suffering from anxiety and tension took part
in the study, with half the group getting kava and the other half placebo. Less anxiety
was already noted in the kava group after I week. By 4 weeks, the difference between the
two groups was striking. Patients taking kava bad an improved sense of well-being and
marked reduction in nervousness and tension. No side effects were noted.19
The same extract and dosage were used in a study with women suffering from anxiety
associated with menopause.20 Again, compared to placebo, use of kava led to
less anxiety and enhanced well-being. Treatment with kava was well tolerated. Two
earlier clinical trials21,22 demonstrated that an isolated kava lactone,
D,L-kavain, reduced anxiety without side effects. One study compared kava directly with
oxazepam and found it to be equally effective in reducing anxiety over a 4-week period.22
Because of the synergistic actions of the combined kava lactones, the preferred
delivery form combines all these constituents.
HOW TO USE KAVA
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A kava extract containing 70 percent
kava lactones is the current standard. The daily dose is 100 milligrams taken two to three
times daily (this is equivalent to 140 to 210 milligrams of kava lactones daily). Evaluate
its antianxiety effects over a 4- to 8-week period.
At this therapeutic dosage the only reported side effects are mild gastrointestinal
disturbances. Long-term consumption may turn the skin yellow temporarily. If this occurs,
you should stop taking kava. In rare cases, an allergic skin reaction (rash) may occur.
The intake of large quantities of nonstandardized kava liquid preparations can led to a
dry, scaly skin rash known as "kava dermopathy" Problems with equilibrium (body
balance) have also been reported. Risk of this rash or equilibrium problems occurs only at
kava lactone dosages in excess of several grams daily.
Kava is not recommended for use by pregnant or lactating women. I also would not recommend
it for young children. The German Commission E monograph on kava also warns against using
it with other substances that may act on the central nervous system, such as alcohol,
barbiturates, and antidepressants.23 However, a recent study did not find any
negative effects when kava and alcohol were combined.24
RELATED CONDITION DISCUSSED IN PART 6
Anxiety
References
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1. Singh YN: Kava: An overview. J
Ethnopharmacol 37:13-45, 1992.
2. Newell WH: The kava ceremony in Tonga. J Polynesian Soc 56:364-417, 1947.
3. Singh YN: Kava: A Bibliography, Pacific Information Center, University of the
South Pacific, Suva, Fiji, 1986.
4. Lebot V, Merlin M, and Lindstrom L Kava: The Pacific Drug. Yale University
Press, New Haven, Connecticut, 1992.
5. Murray NIT Natural anxiolytics-kava and L.72 anti-anxiety formula. Am J Nat Med
1: 10-14, 1994.
6. Weiss RF: Herbal Medicine. Ab Arcanum, Gothenberg, Sweden, 1988, p. 298.
7. Lewin L: Uber Piper methysticum (Kawa). A. Hirschwald, Berlin, 1886.
8. Meyer HJ: Pharmacology of kava. In: Ethnopharmacoligcal Search for Psychoactive
Drugs (Efron DH, Holmstedt B, and Kline NS, eds.). Raven Press, New York, 1979, pp.
133-140.
9. Bone K: Kava-a safe herbal treatment for anxiety. Br J Phytother 3:145-153,
1994.
10. Buckley JP, Furgiulel AR, and O'Hara MJ: Pharmacology of kava. In: Ethnopharmacological
Search for Psychoactive Drugs (Efron DH, Helmstedt B, and Kline NS, eds.). Raven
Press, New York, 1979, pp. 141-15 1.
11. Davies LP, Drew CA, et al.: Kava pyrones and resin: Studies on GABAA, GABAB and
benzodiazepine binding sites in rodent brain. Pharmacol Toxicol 71:120-126, 1992.
12. Holm E, Staedt U, et al.: Studies on the profile of the neurophysiological effects of
D,L-kavain: Cerebral sites of action and sleep-wakefulness-rhythm in animals. Arzneim-Forsch
Drug Res 41:673-683,1991.
13. Jamieson DD and Duffield PH: The antinociceptive actions of kava components in mice. Clin
Exp Pharmacol Physiol 17:495-508, 1990.
14. Kretzschmar R and Meyer Hj: Vergleichende unterschungen ijber die antikonvulsive
wirksamkeit der pyronverbindungen aus Piper methysticum Forst. Arch Int Pharmacodyn
Ther 177:261-77,1969.
15. BackhauB and Krieglstein J: Extract of kava (Piper methysticum) and its methysticin
constituents protect brain tissue against ischeinic damage to rodents. Eur J Pharmacol
215:265-269, 1992.
16. Johnson D, Frauendorf A, et a].:
Neurophysiological active profile and tolerance of kava extract WS 1490. Therapiewoche
Neurologie Psychiatr 5:349-354, 1991.
17. Saletu B, Grimberger J, et al.: EEG-brain mapping, psychometric and
psychophysiological studies on the central effects of kavain-a kava plant derivative. Hum
Psychopharmacol 4:169-190,1989.
18. Munte TF, Heinze HJ, et al.: Effects of oxazepam and an extract of kava roots (Piper
methysticum) on event-related potentials in a word-recognition task. Pharmacoelectroencephalography
27:46-53, 1993.
19. Kinzler E, Kr6mer J, and Lehmann E: Efficacy of kava special extract in patients with
conditions of anxiety, tension and excitation of non-psychotic origin. Amneim-Forsch
Drug Res 41:584-588,1991.
20. Warnecke G: Psychosomatic disorders in the female climacterium: Clinical efficacy and
tolerance of kava extract WS 1490. Fortsch Med 109:119-122, 1991.
21. Scholing WE and Clausen HD: On the effect of D,L-kavain: Experience with neuronika. Med
Klin 72:1301-1306,1977.
22. Kindenberg VD and Pitule-Schbdel H: D,L-Kavain in comparison with oxazepam in anxiety
states. Fortschr Med 108:49-54, 1990.
23. Monograph, Kava-Kava rhizome (Piperis methystici Rhizoma). Bundesanzeiger,
June 1, 1990.
24. Herberg KW. Effect of special extract WS 1490 combined',vith ethyl alcohol on
safety-relevant performance parameters. Blutalkohol 30:96-105, 1993.
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