•  Anxiety

Kava (Piper methysticum ) is a plant from the pepper family native to the South Pacific islands. The herbal remedy, also known as kava kava, is derived from the root of the flowering shrub. For centuries, this root was chewed or mashed into a pulp and then mixed with water or coconut milk -- and sometimes fermented -- to make a pungent drink used for ceremonial and spiritual purposes. Even today, this mildly intoxicating beverage is often served to dignitaries visiting Polynesia. Among those who have supposedly come under its relaxing spell: Hillary Clinton and Pope Paul II. However, in 2002 the Food and Drug Administration issued a warning that the supplement has been linked to liver toxicity, hepatitis, and cirrhosis (See "How Safe Is It?" below). Canada and several European countries have prohibited the sale of all kava products citing potential side effects and interactions with other drugs.

Human studies found kava extract was helpful for short-term treatment of anxiety disorders. In one six-week trial involving 164 people with anxiety disorders, those who took kava fared as well as those who took two commonly used anti-anxiety drugs (oxazepam and bromazepam). And it seems that kava doesn't impair memory, and it isn't addictive.

The active ingredients in kava are known as kavalactones or kavapyrones. These substances seem to work by reducing the amount of chemical activity in the brain and nervous system, similar to the prescription sedative, Valium (Diazepam). Some kavalactones are known to slow the breakdown of the mood chemical norepinephrine. They may also function as muscle relaxants and pain-relievers.

Serious liver problems have been reported in some people who took kava. After at least 30 cases of hepatitis, one death and four liver transplants in Europe were attributed to regular ingestion of kava, France, Switzerland, and Germany outlawed kava. Germany officially rescinded its ban in 2005, but has yet to allow kava kava back on the market. In the United States, the Food and Drug Administration is investigating whether kava is the culprit in reported cases of liver toxicity. Meanwhile, the FDA urges anyone who has liver problems, or who is taking medications that can affect the liver, to consult a physician before using supplements that contain kava. If you suspect that you're suffering from an anxiety disorder, see a doctor or therapist for a diagnosis and discussion of appropriate treatment options.

Herbal experts also note that some people might have significant side effects from kava after taking it for more than one month, and advise against taking it longer than that. Common side effects are drowsiness (don't drive after taking it), stomach upset, headache and dizziness. Chewing kava root can cause numbness or tingling in the mouth. You may experience a mild morning "hangover" especially after you first start taking it. People who use large amounts of kava for longer than three months can develop a scaly rash and eye irritation, called kava dermopathy. These symptoms generally go away when patients stop taking the herb.

Other cautions: Pregnant and nursing women should not use kava. Do not use kava if you are already taking benzodiazepines, barbiturates, or any other sedative drugs, and do not take kava with alcohol. If you are taking prescription medicines, check with your doctor or pharmacist before using kava. People with liver disease should not use kava -- serious liver problems have been reported in some people who took kava.

Kava is sold by mail-order distributors, in health food stores and in pharmacies. It comes in liquid form, capsules, and in a powder that can be mixed into drinks. Extracts containing 70 percent kavalactones were used in human trials to treat anxiety. Take kava with food to aid absorption. Keep in mind that the government does not regulate herbs, so quality and potency can vary from product to product. In rare cases herbal products may be contaminated with undesirable substances.

-- Rachele Kanigel is a freelance writer and journalism professor in Oakland, California, who specializes in health and science reporting. Her work has appeared in Time, Health, Hippocrates, and other publications. She has taught journalism at San Francisco State University and California State University Monterey Bay.

References

First published September 3, 1998
Last updated January 24, 2008
Copyright © 1998 Consumer Health Interactive and OneBody, Inc.

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