The Curious Case of Kava

By Lev Grossman

Kava is a far-flung relative of the pepper plant that grows on the remote tropical islands of Polynesia. It's famous for the calm, dreamy state of mind it induces, and the locals have used it for centuries to celebrate weddings and greet visiting royalty. Kava enthusiasts claim that it can ease anything from anxiety and insomnia to menopause. In sleepless, stress-rattled America, consumers spend more than $50 million on kava--kava drinks, kava drops, kava capsules, kava candy and kava tea.

These days kava users aren't feeling quite so calm. Reports of liver damage have been piling up in Europe and the U.S.--including the case of a previously healthy 45-year-old American woman who took kava and suddenly needed a liver transplant. Last week the Food and Drug Administration finally issued a kava alert. Sales of the herb had already been halted in France and Switzerland and suspended in Britain. German authorities are in the process of reclassifying it as a prescription drug.

What took the FDA so long? The answer says a lot about a regulatory loophole created by the 1994 Dietary Supplements Health and Education Act. Under this law, herbal products like kava are classified as dietary supplements. Neither food nor drugs, they don't have to be proved safe or effective before being sold in the U.S. If there's something wrong with them, the burden of proof falls on the FDA, which does not have the money or the staff to evaluate every new herb, vitamin, mineral and enzyme that comes to market. "We don't have a lot of resources," acknowledges Dr. Christine Taylor, who heads the FDA office that handles dietary supplements.

How kava came to market is part of what makes its story so interesting. The Western world has known about kava's powers since the 18th century, when Captain Cook spotted Polynesians chewing its roots. But it didn't catch on in the U.S. until 1996, when a group of herbal-product purveyors called the Kava General Committee decided to pool their resources and make kava America's herb du jour. That year, supported by a heavy promotional campaign, retailers moved $15 million worth of the stuff, elevating it to the pantheon of big-name herbal remedies like ginkgo biloba and St.-John's-wort. It wasn't long before kava vaulted out of the health-food ghetto and into the aisles of supermarkets and K Marts.

By last fall, evidence against kava was starting to pile up. Health authorities in Switzerland and Germany had gathered records of close to 30 incidents--"adverse-event reports," in the clinical jargon--in which kava users suffered severe liver damage. A few patients required transplants, and at least one died. The response in Europe has been swift and decisive. In the U.S., however, the FDA's hands are tied until researchers can establish a definite causal link between kava and liver disease. That could take years.

Not that they will necessarily find a link. A four-week study carried out at the Duke University Medical Center this fall concluded that kava, used responsibly, poses no significant health hazard. "We didn't observe any abnormalities in liver function or any other significant side effects," says Dr. Kathryn Connor, one of the authors of the study. She points out that some of the cases reported in Europe were complicated by extraneous factors; some patients had been taking extremely high doses of kava over long periods of time, or using it with alcohol, or taking it on top of a pre-existing liver condition. (Signs of liver trouble include jaundice, nausea, light-colored stools, fatigue and stomach pain.)

So how much kava is too much? The American Botanical Council recommends that people who have liver trouble or who drink a lot of alcohol stay away from the herb. Everybody else should be careful not to take kava every day for more than four weeks straight and not to exceed the recommended dosage. In Germany, where herbal supplements are scrutinized much more closely than in America, 60 mg to 120 mg of kavalactone (the active ingredient in kava) is considered a reasonable daily dose. When you buy a kava product, be sure to check the kavalactone concentration listed on the label. And above all, try to relax.