Review of Kava Cases
Wyn Snow, Managing Editor
response to concerns raised by recent cases of liver toxicity in
people who were taking supplements containing kava (Piper methysticum),
a group of supplement trade associations hired toxicologist Donald
Waller to examine the evidence.
Waller found that the existing evidence does not indicate that kava
use caused the liver disease. However, the available medical information
lacks important details, and Dr. Waller recommended that additional
information be provided in order to be entirely conclusive.
evidence appears to indicate idiosyncratic responses
Waller reported to the US Food and Drug Administration (FDA) on
19 February 2002 that "there is no clear evidence that the liver
damage reported in the US and Europe was caused by the consumption
of kava." Cases with a possible association between kava intake
and liver problems "appear to have been hypersensitivity or idiosyncratic
Waller also pointed out two cases of consumption of very large quantities
of kava which "provide some evidence that kava itself is not a direct
hepatotoxin even in extremely high concentrations."
mix kava with known liver problems
Waller recommended that both physicians and consumers be made aware
that people should avoid kava if they:
prescription drugs associated with liver damage
large amounts of alcohol
pre-existing liver disease or compromised liver function
supplement groups and toxicologist
group that hired Dr. Waller consists of the American Herbal Products
Association (AHPA), the
Council for Responsible Nutrition (CRN),
the National Nutritional Foods Association (NNFA)
and the Utah Natural Products Alliance (UNPA).
P. Waller, PhD, is a Professor of Pharmacology and Toxicology in
the Department of Pharmaceutics and Pharmacodynamics at the University
of Illinois at Chicago's College of Pharmacy, and is also a Diplomate
of the American Board of Toxicologists.
Herbal Products Association, private communication, 26 March 2002.