Eating Well

NEW QUESTIONS ABOUT KAVA'S SAFETY

IN Europe, the reaction was swift. On Nov. 8, German scientists
reported that kava, an herbal supplement promoted for stress
reduction, may be responsible for 30 cases of liver toxicity in
Germany and Switzerland. Switzerland pulled kava off the market.
Britain asked for its voluntary withdrawal. And Germany warned
manufacturers that it may soon ban kava. Last week, France banned its
sale.

In the United States, more than two months after the toxicity reports
came to light, the Food and Drug Administration has issued no public
warnings or advice. And, the agency says, by law it cannot.

Instead, it is studying the adverse reactions in 60 kava-related cases
reported in this country since 1998. They include hepatitis, jaundice
and liver failure. Joseph A. Levitt, the director of the Center for
Food Safety and Applied Nutrition at the agency, said, "Two of those
cases do raise a signal for us that this is something that warrants a
lot of further investigation."

The study, he said, could take a year or more, and until it is
completed, the agency cannot take any action.

Kava, also called kavakava, is a leafy plant that grows on Pacific
islands. The processed root is the most potent part, but all of it is
used. It has a tradition in a mood-altering drink among Pacific
islanders, who often take it on ceremonial occasions.

In the last five years, it has become increasingly popular in the
United States for alleviating anxiety and stress. Among herbal
supplements, kava ranks ninth in sales. For the year ending in
November, sales were more than $34 million, according to Spins, a San
Francisco market research firm for the health industry, and ACNielsen.

In asking for voluntary withdrawal, the British Medicines Control
Agency said it was assessing the emerging evidence, and "in the
meantime in view of the potential concerns over safety, it would be
prudent for the public to stop taking any product or remedy containing
kavakava."

Like some other European countries, Britain is using the precautionary
principle, a philosophy seldom followed by United States regulatory
agencies.

Instead, on Dec. 19 the Food and Drug Administration sent a letter to
health professionals asking for help in determining whether there is a
problem, seeking a review of "cases of liver toxicity to determine if
any may be related to use of kava-containing dietary
supplements."

Mr. Levitt said his agency's hands were tied by the Dietary Supplement
Health and Education Act of 1994. Although kava is widely used as an
alternative to prescription drugs, it has never been subject to the
rigorous scientific testing required before prescription and
over-the-counter drugs can be sold. Pre-market approval is not
required for herbal remedies and, as Mr. Levitt said: "The dietary
supplement law is written so that a product like this goes on the
market. Then, if there is significant evidence of harm, the F.D.A.
takes action."

Herbal supplements are subject to study and regulation in Germany but
are not subject to prescription drug testing. Instead the German
government's committee of experts -- Commission E -- sets standards.
Commission E determines safety and effectiveness from published
historical and chemical data, clinical, animal and experimental
studies. It reviews meta-analyses (combinations of small studies) and
patient case records. It has accepted 200 of the 300 herbs it has
studied. The remaining 100 were rejected because they were not safe or
there was inadequate documentation of their effectiveness or benefit.

The Food and Drug Administration does not accept the German research
but must conduct its own. And the agency has not been able to get
enough information from the Germans about their cases. "It's very
frustrating," Mr. Levitt said.

There are unanswered questions. Is kava alone responsible for liver
toxicity, or was it taken with other medications that may be at fault?
Was there a reaction between kava and other medications? Was a
contaminant introduced in the manufacturing? Did those who became ill
have a pre-existing liver problem? Was alcohol abuse involved?

Kava has not undergone the same strict risk assessment to which
benzodiazepines (tranquilizers like Valium and Librium) were
subjected, said Mark Blumenthal, the founder and executive director of
the American Botanical Council. "The risks for kava are automatically
magnified because the benefits were not established by the same strict
standards," he said.

While the Food and Drug Administration offers no advice, Dr. Paul
Coates, director of the Office of Dietary Supplements at the National
Institutes of Health, said he would not take kava. "People should be
cautious," he said. "Why expose yourself to potentially harmful
ingredients? The benefit is pretty much irrelevant until the risk is
known. The use of dietary supplements has outstripped the science to
support their use."

Dr. Coates's agency is conducting clinical trials on the safety and
effectiveness of herbal supplements, but, he said, "It could take 20
years to do the top 20 supplements."

Dr. Norman Farnsworth, a research professor of pharmacognosy at the
University of Illinois, said the industry should attach a label to
kava products warning people not to take them more than a week or two
at a time if they have liver problems. "If you have to take kava every
day, you've got a problem," he said. "But if you take it two or three
times a week for a couple of weeks and then lay off and then do it
again, I don't think you will have a problem."