Description
Kava kava (Piper methysticum) is a tropical shrub that grows throughout the Pacific Islands. Kava kava belongs to the pepper family (Piperaceae) and is also known as kava, asava pepper, or intoxicating pepper. It grows to an average height of 6 ft (1.83 m) and has large heart-shaped leaves that can grow to 10 in (25.4 cm) wide. A related species is Piper sanctum, a native plant of Mexico that is used as a stimulant.
Kava kava has been used as a medicinal herb for hundreds of years and used by Pacific Islanders to treat rheumatism, asthma, worms, obesity, headaches, fungal infections, leprosy, gonorrhea, vaginal infections, urinary infections, menstrual problems, migraine headaches, and insomnia. It was also used as a diuretic, an aphrodisiac, to promote energy, and to bring about sweating during colds and fevers. Pacific Islanders consume a kava kava drink at social, ritual, and ceremonial functions. It is drunk at ceremonies to commemorate marriages, births, and deaths; in meetings of village elders; as an offering to the gods; to cure illness; and to welcome honored guests. Pope John Paul II, Queen Elizabeth II, and Hillary Rodham Clinton have all drunk kava kava during their island visits.
The drink is prepared by grinding, grating, or pounding the roots of the plant, then soaking the pulp in cold water or coconut milk. Traditionally the root was chewed, spit into a bowl, and mixed with coconut milk or water. That practice is no longer the standard.
Captain James Cook has been credited with the Western discovery of kava kava during his journey to the South Pacific in the late 1700s. The first herbal products made from kava kava appeared in Europe in the 1860s. Pharmaceutical preparations became available in Germany in the 1920s. Currently, kava kava has received widespread attention because of its reputation to promote relaxation and reduce stress.
General Use
Kava kava has been prescribed by healthcare providers to treat a wide range of ailments, including insomnia, nervousness, and stress-related anxiety and anxiety disorders. It is also reported to relieve urinary infections, vaginitis, fatigue, asthma, rheumatism, and pain.
The active ingredients in kava kava are called kavalactones and are found in the root of the plant. Kavalactones cause reactions in the brain similar to pharmaceutical drugs prescribed for depression and anxiety. Research has shown that kavalactones have a calming, sedative effect that relaxes muscles, relieves spasms, and prevents convulsions. Kavalactones also have analgesic (pain-relieving) properties that may bring relief to sore throats, sore gums, canker sores, and toothaches.
Kava kava is a strong diuretic that is reportedly beneficial in the treatment of gout, rheumatism, and arthritis. The diuretic effect of the herb relieves pain and helps remove waste products from the afflicted joints. Antispasmodic properties have shown to help ease menstrual cramps by relaxing the muscles of the uterus. Kava kava's antiseptic and anti-inflammatory agents may help relieve an irritable bladder, urinary tract infections, and inflammation of the prostate gland.
Preparations
Kava kava is available in dry bulk (powdered or crushed), capsule, tablet, tea, and tincture forms. Many of the products are made from the dried powder of the root. Western consumers have generally been advised to look for standardized extracts of kava kava that have a 70% kavalactone content. On the other hand, a report submitted to the Committee of Safety of Medicines (CSM) of the United Kingdom in April 2002 indicates that many of the side effects reported in connection with kava kava are due to the high concentration of the herb in commercial standardized extracts. The report suggested that kava preparations made according to traditional methods are relatively safe. It is likely that controversy over kava kava will continue.
Precautions
Before 2002, the usual precautions regarding kava kava stated that it should not be used by pregnant or lactating women, or when driving or operating heavy machinery. The American Herbal Products Association (AHPA) advised consumers in 1997 not to take kava kava for more than three months at a time, and not to exceed the recommended dosages. In light of more recent findings, however, it would be prudent for many adults to completely avoid preparations of or products containing kava kava.
As of March 25, 2002, the United States Food and Drug Administration (FDA) has recommended that people who have a history of liver disease or are taking medications that affect the liver should consult a physician before taking any preparations containing kava kava.
Side Effects
Prior to 2002, most reports of side effects from kava kava concerned relatively minor problems, such as numbness in the mouth, headaches, mild dizziness, or skin rashes. Nineteenth-century missionaries to the Pacific islands noted that people who drank large quantities of kava kava developed yellowish scaly skin. A more recent study found the same side effect in test subjects who took 100 times the recommended dose of the plant.
As of 2002, however, kava kava has been associated with serious side effects involving damage to the liver, including hepatitis, cirrhosis, and liver failure. Most of the research on kava kava has been done in Europe, where the herb is even more popular than it is in the United States. By the late fall of 2001, there had been at least 25 reports from different European countries concerning liver damage caused by the plant. French health agencies reported one death and four patients requiring liver transplants in connection with kava kava consumption. On December 19, 2001, the MedWatch advisory of the U. S. Food and Drug Administration posted health warnings about the side effects of kava kava; and on January 16, 2002, Health Canada advised Canadians to avoid all products containing the herb. France banned the sale of preparations containing kava kava in February 2002. The U. S. National Center for Complementary and Alternative Medicine (NCCAM) put two research studies of kava kava on hold while awaiting further action by the FDA. NCCAM advised consumers in the United States on January 7, 2002 to avoid products containing kava. On March 25, 2002, the FDA issued a consumer advisory and a letter to health care professionals concerning the risk of severe liver damage from the use of products containing kava kava. While the most recent actions on the part of the FDA stop short of banning kava products from the U. S. market, the agency asks consumers as well as medical practitioners to notify its Med-Watch hotline of any liver damage or other injuries associated with using kava kava. The MedWatch toll-free number is (800) 332-1088.
In addition to causing liver damage, kava kava appears to produce psychological side effects in some patients. Beverages containing kava kava have been reported to cause anxiety, depression, and insomnia. In addition, kava kava has caused tremors severe enough to be mistaken for symptoms of Parkinson's disease in susceptible patients.
Interactions
Kava kava has been shown to interact with beverage alcohol and with several categories of prescription medications. It increases the effect of barbiturates and other psychoactive medications; in one case study, a patient who took kava kava together with alprazolam went into a coma. It may produce dizziness and other unpleasant side effects if taken together with phenothiazines (medications used to treat schizophrenia). Kava kava has also been reported to reduce the effectiveness of levodopa, a drug used in the treatment of Parkinson's disease.
Some interactions between kava kava and prescription medications, as well as some of the herb's side effects, have been attributed to synergy (combined effects) among the various chemicals contained in kava kava rather than to any one component by itself.
Resources
Books
Cass, M.D., Hyla, and Terrence McNally. Kava: Nature's Answer to Stress, Anxiety, and Insomnia. Schoolcraft, MI: Prima Communications, Inc., 1998.
Connor, Kathryn M. and Donald S. Vaughan. Kava: Nature's Stress Relief. New York: Avon Books, 1999.
Lebot, Vincent, Mark Merlin, and Lamont Lindstrom. Kava: The Pacific Elixir: The Definitive Guide to Its Ethnobotany, History, and Chemistry. Rochester, VT: Inner Traditions International, Limited, 1997.
Robinson, Ph.D, Maggie Greenwood. Kava: The Ultimate Guide to Nature's Anti-Stress Herb. New York: Dell Publishing Company, Inc., 1999.
Periodicals
Almeida, J. C., and E. W. Grimsley. "Coma from the Health Food Store: Interaction Between Kava and Alprazolam." Annals of Internal Medicine 125 (1996): 940-941.
Ballesteros, S., S. Adan, et al. " Severe Adverse Effect Associated with Kava-Kava." Journal of Toxicology: Clinical Toxicology 39 (April 2001): 312.
Beltman, W., A. J. H. P van Riel, et al. "An Overview of Contemporary Herbal Drugs Used in the Netherlands. " Journal of Toxicology: Clinical Toxicology 38 (March 2000): 174.
Bilia, A. R., S. Gallon, and F. F. Vincieri. "Kava-Kava and Anxiety: Growing Knowledge About the Efficacy and Safety." Life Sciences 70 (April 19, 2002): 2581-2597.
Denham, A., M. McIntyre, and J. Whitehouse. "Kava—The Unfolding Story: Report on a Work-in-Progress." Journal of Alternative and Complementary Medicine 8 (June 2002): 237-263.
Ernst, E. "The Risk-Benefit Profile of Commonly Used Herbal Therapies: Ginkgo, St. John's Wort, Ginseng, Echinacea, Saw Palmetto, and Kava." Archives of Internal Medicine 136 (January 1, 2002): 42-53.
" France is Latest to Pull Kava Kava Prods." Nutraceuticals International (February 2002): np.
Humbertson, C. L., J. Akhtar, and E. P. Krenzelok. "Acute Hepatitis Induced by Kava Kava, an Herbal Product Derived from Piper methysticum." Journal of Toxicology: Clinical Toxicology 39 (August 2001): 549.
Meseguer, E., R. Taboada, V. Sanchez, et al. "Life-Threatening Parkinsonism Induced by Kava-Kava." Movement Disorders 17 (January 2002): 195-196.
Spinella, M. "The Importance of Pharmacological Synergy in Psychoactive Herbal Medicines." Alternative Medicine Review 7 (April 2002): 130-137.
Organizations
American Botanical Council (ABC). P.O. Box 144345, Austin, TX 78714-4345. (512) 926-4900. Fax: (512) 926-2345. .
FDA Center for Food Safety and Applied Nutrition (FDA/CFSAN). .
NIH National Center for Complementary and Alternative Medicine (NCCAM) Clearinghouse. P. O. Box 8218, Silver Spring, MD 20907-8218. TTY/TDY: (888) 644-6226. Fax: (301) 495-4957. .
NIH Office of Dietary Supplements. Building 31, Room 1B25. 31 Center Drive, MSC 2086. Bethesda, MD 20892-2086. (301) 435-2920. Fax: (301) 480-1845. .
Other
FDA/CFSAN. Consumer Advisory, March 25, 2002. "Kava-Containing Dietary Supplements May be Associated with Severe Liver Injury." .
FDA/CFSAN. Letter to Health Care Professionals, March 25, 2002. "FDA Issues Consumer Advisory That Kava Products May be Associated with Severe Liver Injury." .
[Article by: Jennifer Wurges; Rebecca J. Frey, PhD]
