Kava kava ban: your questions answered
Monday 24 July 2006
The Food Standards Agency introduced regulations to ban the sale or distribution of kava kava in England on 13 January 2003. A consultation on the scientific evidence for the ban was carried out in 2005. The results of the consultation support the continuation of the ban on kava kava.
The majority of products that kava kava was used in are classed as herbal medicines and are regulated in the UK by the Medicines Control Agency (MCA). However, there were some food products containing kava kava, for example herbal tea bags, 'smoothie' drinks, cereal bars and vodka products. In addition, internet sites offered kava kava root and root powder for sale.
Evidence has mounted that in rare cases the use of products containing kava kava (mostly in the form of herbal medicines) has been associated with severe liver damage. The occurrence of liver damage is unpredictable and the mechanism is unclear.
To date, the Agency is aware of 110 cases of severe liver damage (hepatoxicity), possibly associated with the use of kava kava containing products. Eleven patients have suffered irreversible liver failure and received a liver transplant. Overall, nine patients have now died, including two who had received liver transplants.
The then Medicines Control Agency (MCA), now the Medicines and Healthcare products Regulatory Agency (MHRA) sought advice on kava kava from two groups of independent experts that advise them on the safety of medicines – the Committee on Safety of Medicines (CSM) and the Medicines Commission. Both found evidence of a risk, in rare cases, of liver damage associated with the use of unlicensed medicines containing kava kava and advised that they should be prohibited in order to protect public health.
Food Standards Agency scientists reviewed the data available to the CSM and MC and assessed the risks for food uses. The Chair of the Committee on Toxicity was consulted on these risks and agreed that consumption of kava kava may be associated with serious liver damage.
The MHRA continues to advise against the use of herbal remedies containing kava kava, and in parallel action brought in legislation to ban its use in herbal products. The Medicines for Human Use (kava kava) (Prohibition) Order 2002 also came into force on 13 January 2003.
In 1990, the addition of tryptophan (an amino acid) to foods was banned in most cases. That action followed a relatively small number of cases of serious illness in people who were taking tryptophan in the form of dietary supplements. There are many cases of medicines that have been removed from the market due to liver toxicity. Following a review of scientific evidence, tryptophan has now been reintroduced to the UK market in the form of food supplements with an upper daily dose level of 220mg.
The 2005 consultation took place to fulfil a commitment made by Ministers, to review the available evidence relating to the safety of kava kava two years after the prohibition had been in place. A similar consultation was undertaken for kava kava in unlicensed herbal products by the MHRA.
Evidence was submitted by interested parties, and a review was undertaken of all new papers published since the original ban was put in place in 2002. Background papers are available from COT papers
Members of the Committee on Toxicity (COT) reviewed all the evidence presented to them. Background papers and minutes are available on COT background papers and minutes
Members considered that the new data were not sufficient to demonstrate the safety of food products containing kava kava, particularly considering the severe nature of the hepatoxicity linked with kava kava consumption. The new studies on metabolism did not help to identify a mechanism of hepatoxicity. Reports of hepatoxicity were still occurring, including cases related to traditional kava kava preparations. Concern was also expressed about the lack of controls over production of food such as the extraction method and the parts of the plant used in the extracts. Overall, members concluded that the new data did not warrant a change in their previous advice.