Many of you have written to us recently about kava. The news has been full of reports connecting this popular herb with liver toxicity. Understandably, people are confused and concerned.
Fortunately, we have a kava expert on the HSI panel. Hyla Cass, M.D., is an orthomolecular physician and a psychiatrist, as well as the author of several books, including “Kava: Nature’s Answer to Stress, Anxiety, and Insomnia.” So we asked Dr. Cass to write to you today to address the concerns we’ve heard about kava. I think you’ll find her insight very interesting – it certainly puts a new perspective on the coverage we’ve been seeing in the mainstream media. Here’s what she had to say
HSI panelist tells the REAL story about kava
The South Pacific herb, kava kava, is one of the most popular herbs on the market, based on its proven ability to relieve stress, anxiety, and tension. But recently, kava has come under the scrutiny of the Food and Drug Administration (FDA), which is acting on reports from Europe that kava may damage the liver. German and Swiss health authorities have identified approximately 30 cases of sometimes-serious liver toxicity, including four cases requiring transplantation and one death, which are believed to be associated with kava consumption. Based on these reports, the U.K. banned sales of kava products, and German authorities notified manufacturers of kava products that their licenses to market the herb could be withdrawn. In the U.S., the FDA sent a letter to doctors requesting that any adverse events associated with the use of kava products be promptly communicated to FDA’s “Medwatch Program.”
There are scant details available from the 30 European cases, but a closer examination reveals that the vast majority (21 cases) involved the simultaneous use of hepatotoxic drugs (drugs that poison the liver) and/or alcohol. This is certainly not significant evidence of kava causing hepatotoxicity.
And the information that has been reported through the FDA MedWatch program is not entirely reliable. For example, the Medwatch site contains reports of numerous “kava toxicity” cases stemming from a product sold at a 1996 New Year’s Eve rave (dance) event. Initial reports alleged that the product contained kava, but in fact, it contained a highly toxic industrial chemical, called 1,4-butane-diol — and absolutely NO kava. The Los Angeles police department toxicologists published a report to this effect within weeks. Nonetheless, these spurious claims against kava have remained on the FDA website ever since.
As with the European cases reported above, when the most recent FDA reports on kava are examined more closely, it is clear that most cases of liver toxicity involved the use of multiple drugs, and in some cases, alcohol abuse. There is no evidence that kava was the primary cause of these problems.
Valium or Tylenol more likely to damage your liver than kava
The fact is, you are far likelier to suffer from liver damage by taking the prescription anti-anxiety drug, Valium, then you are by taking kava, yet Valium is taken by millions daily with little question-and with no major adverse publicity. The over-the counter pain medication, acetaminophen, which is the main ingredient in Tylenol, also has a high incidence of liver toxicity, especially when combined with alcohol.
Kava has a long tradition of use in the South Pacific at often considerably higher doses than those used in Europe, with few reported liver toxic effects, and its safety/toxicity has been studied extensively in recent years. The longest running study conducted to date, with 101 people taking 70 mg three times a day for six months, showed negligible side effects, and in fact, more of the placebo subjects reported side effects than those taking kava. The researcher concluded that, “in contrast to both benzodiazapines (the class of sedative drugs that includes Valium) and antidepressants, kava possesses an excellent side-effect profile.”
The safe and effective anxiety-relieving benefits of kava were also supported in a meta-analysis, a systematic statistical review of seven human clinical trials published in 2000 in the Journal of Clinical Psychopharmacology, and again in a similar critical review in 2001. The reviews did not find significant adverse effects related to liver toxicity.
Should you change the way you use kava?
There has been a strong response from the herbal industry to ensure kava’s safety. A coalition of trade associations of the dietary supplement industry is actively engaged in evaluating the information that has been made available by the German regulatory authorities.
In the meantime, Mark Blumenthal of the American Botanical Council recommends that kava users consider the following: Kava should not be used by anyone who has any liver problems, or by anyone who is taking any drug product with known adverse effects on the liver, or anyone who consumes alcohol regularly.
Since the reports so far are associated with chronic use, Blumenthal suggests considering that kava not be taken on a daily basis for more that four weeks. (Note: I consider that to be overly conservative, preferring the German Commission E’s recommendation of three months.)
In addition, Blumenthal noted that consumers should discontinue use if symptoms of jaundice (e.g., dark urine, yellowing of the eyes) occur.
Consumers should consult their primary healthcare provider if they have a history of liver problems or suspect possible liver problems before using kava or continuing its use.
We must be aware that herbs are potent medicines, which must be treated with the appropriate respect regarding potential interactions and toxicity. On the other hand, kava’s margin of safety far surpasses that of its pharmaceutical equivalent. Nothing would be gained by having previously satisfied kava consumers switch to a more toxic prescription medication, such as a benzodiazepine, in the mistaken belief that they were making a safer choice.
Hyla Cass, MD
For updates on kava and other herbal news, visit Dr. Cass’s website at www.cassmd.com.
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