Kava, also known as kava-kava or Piper methysticum, is a member of the pepper family indigenous to the islands of South Pacific such as Polynesia, Melanesia, Vanuatu, Micronesia, and Australia. It has been a highly regarded crop by Pacific islanders for many centuries. The roots of kava (a perennial shrub) are used by natives to make a special traditional drink (also called kava) which is consumed during social, political, and religious ceremonies. The effects of kava to the body are similar to alcohol but it does not stimulate aggressive behavior, depress mental clarity, or cause a hangover. Kava relaxes the muscles and gives a person a feeling of calmness and sense of well-being.
Kava is now a popular herbal remedy for anxiety, insomnia, restlessness, stress, and menopausal symptoms. Unlike alcohol and other drugs, kava is generally non addictive. It is sold in various forms: beverage, tablets, capsules, tincture, powder, and tea. Today, the supply of kava cannot already catch up with the increasing global demand. It takes at least 4-5 years to grow kava. Harvesting kava roots younger than 4 years is not recommended because they contain little bioactive compounds. But due to high demand, farmers are forced to harvest kava as young as 18 months.
The active compounds found in kava are called kavalactones. Kavalactones are released when kava root is chewed or ground with little water. They can also be extracted with alcohol solvent. Fresh kava root is made up of 80% water. Dried root on the other hand is made up of 15% kavalactones, 20% fibers, 43% starch, 12% water, 3.6% proteins, 3.2% sugars, and 3.2 percent minerals. The root contains the greatest kavalactone content in the whole plant. Kavalactone concentration decreases higher up the plant. Studies suggest that kavalactone works with neurotransmitters (e.g. GABA) to cause neurological changes in the body.
Side Effects and Safety Concerns
Some countries ban the use, sale, or importation of kava because of reports that it causes liver damage including hepatitis and liver failure. At least 110 cases of liver damage (as of 2010 accdng. to FSA, UK) have been reported by health authorities of U.K., Germany, France, Switzerland, and Canada. However, there is no enough evidence that shows liver toxicity of kava root extract. There are studies suggesting that extracts from the leaves and stem peelings contain pipermethysine which is toxic to liver cells. Researchers did not found pipermethysine in root extract. Western manufacturers of kava products may have used kava leaves and stem peelings to meet the high demand for kava. They have no prior knowledge about toxicity of extracts from kava leaf and stem peeling. Pacific islanders only use the kava root.
Several cases of abnormal muscle spasm or involuntary muscle movement have been associated to kava use.
Heavy and/or long-term use of kava may result in scaly, yellowed skin as observed in several males living in the Pacific.
Cases of kava allergy have also been reported. Symptoms may include rashes, itching, diarrhea, swelling, breathing difficulty, and anaphylactic shock. People who are allergic to any member of the pepper family are most likely to be allergic to kava.
Kava can cause stomach upset, mild headache, poor coordination, tremor, drowsiness, and fatigue. Because kava causes drowsiness, people should not drive or operate machineries after taking kava.
Kava should not be used by pregnant and breastfeeding women. Kava can decrease the strength of the muscles of the uterus resulting to miscarriage or premature labor. Substances found in kava may pass into breast milk; the effect of kava to unborn baby is unknown.
Kava should be used in moderate amount (just like alcoholic drinks) to prevent or minimize the occurrence of side effects. People are advised to consult their doctors before using kava.
Kava can interact with different medications by increasing or decreasing their effectiveness.
There is an increased risk of liver damage if kava is taken with drugs that may injure the liver such as acetaminophen (Tylenol) and alcohol.
Kava may interfere with the effects of dopamine or medications similar to dopamine.
Kava may add to the effects of antidepressants like monoamine oxidase inhibitors (e.g. Marplan, Nardil, & Parnate).
Kava may cause the effects of anesthesia to last longer. Hence, doctors do not recommend the use of kava 2 to 3 weeks before surgery.
Because kava has blood-thinning properties, it may increase the risk of bleeding when taken with blood thinners or anticoagulants such as warfarin (Coumadin), heparin, and clopidogrel (Palix).[ad#afterpost]
References and Further Reading
- Kava – National Center for Complementary and Alternative Medicine
- Kava Linked to Liver Damage – National Center for Complementary and Alternative Medicine
- Kava (Piper methysticum) – MedlinePlus Supplements
- Kava kava ban: your questions answered – Food Standards Agency, UK
- Kava Fact Sheet – Therapeutic Goods Administration of Australia