Herbs & Supplements

Should I take it?

Kava, a member of the pepper family of plants, grows mainly in the tropical climate of islands in the South Pacific Ocean. Traditionally, it has been used to prepare a ceremonial drink that promotes feelings of well-being--much as alcoholic beverages are used in social settings of Western countries.

Kava plants grow as tall perennial bushes with broad, flat, heart-shaped leaves. Although the plants produce small flowers, they do not produce seeds that will sprout. They spread by sending out rhizomes--fleshy extensions of their stems that run just under the ground and produce new plants. Generally, the rhizomes and roots of kava plants that are 3 years to 4 years old are harvested to make the traditional beverage as well as for medicine. For farming, cuttings are taken of the kava stems when the roots are dug up. One kava stem may produce several new plants. Young kava plants need protection from the sun and the wind, so they are often planted between rows of taller plants such as banana trees or sweet potato plants.

In various parts of the South Pacific, kava has political and religious significance in addition to its medical and social value. Throughout the region, kava beverages traditionally are prepared in a formalized ritual similar to the Japanese tea-preparation ceremony. In some parts of the area, only certain individuals were authorized to make the beverage, which not every member of the group was allowed to drink. Although the details of the ceremonies may differ by region, a typical process involves chewing kava or pounding it in a heavy stone bowl, then mixing it into cool water. Another method is wrapping dried and shredded kava root into a cloth "ball" which is dipped into a container of water until it is thoroughly waterlogged. Then, the water is squeezed out of the ball back into the container. The whole dunking and squeezing process is repeated until the water assumes a slightly thick, cloudy appearance--a few minutes to more than half an hour depending on the location. Now, although traditional ways are still observed in some places, kava beverages are often made from dried, powdered kava in electric blenders. Either way, the resulting beverage, which is said to look like mud or dirty dishwater, has a taste described as slightly bitter and peppery.

Because few cases of liver toxicity have been reported among Pacific Islanders who have taken kava regularly for many years, the reasons for possible kava-related liver problems among Western kava users are not clear. Some affected individuals may have taken larger than recommended doses of kava or used it consistently for long periods. Many were also taking medications, drinking alcohol, or using other substances that contribute to liver injury at the same time they were using kava. Another theory is that genetic differences may cause kava to be used differently by Pacific Island natives and members of Western populations. Individuals with pre-existing liver conditions are more likely to have developed serious liver effects after using kava. Allergic reactions may be involved, as well. Additionally, the amounts of active chemicals in kava depend on how the plants are grown, harvested, processed, and stored. Generally, beverages prepared from fresh kava contain more kava lactones than those made from aged or dried rhizomes. Some commercially made kava may have been contaminated with kava leaves or parts of other plants that contain potentially harmful substances. Finally, commercial preparation of kava may use different solvents or different parts of the kava rhizome, potentially changing the chemical composition of the marketed product.

Dosage and Administration

Until re-evaluations of kava's safety are completed by the FDA and the WHO, the use of kava is not recommended.

Note: As treatment for anxiety, kava may take up to 2 months to reach maximum effectiveness.

Note: Many of the human studies of kava used a preparation that was standardized to contain 70% kava lactones. Most of the kava products on the market are approximately one-half as concentrated. Standardization by the manufacturer should assure the same amount of active ingredient in every batch of the commercial preparation. Standardization of herbal products is not required by the FDA, so not every kava product available in the U.S. contains the same amounts of active ingredients.

Individuals who decide to use kava should check with a doctor or pharmacist first to be sure that they have no conditions or medications that might interact. The directions for dose and frequency should be followed exactly and the use of kava should be limited to 3 months or less. Liver function tests may be needed during the time kava is used.

Summary

Due to its association with cases of liver damage, the oral use of kava is discouraged.

Risks

Because it may worsen liver conditions and Parkinson's disease, kava should be avoided by individuals with those conditions. Those who regularly consume alcoholic drinks should also avoid kava. Pregnant and breast-feeding women should not take it because its possible effects in developing babies and infants are not known.

Side Effects

Deaths and serious liver damage have been attributed to taking kava. It is also suspected of causing rare instances of changes in blood cell numbers, weight loss, shaking, and uncontrollable body movements. A characteristic skin condition known as kawaism or kava dermopathy may result from large doses of kava taken for long periods. Kava has also been associated with dizziness, drowsiness, headaches, stomach upset, and numbness of the mouth.

Interactions

Potentially, kava may interact with alcohol and many drugs or herbals that affect liver function, promote sleep, lessen blood clotting, treat Parkinson's disease, or break down in the liver.

Last Revised October 12, 2007