Expert calls for kava clinical trial to establish safety
efficacy of kava kava and to restore the industry in the South
Pacific is to conduct clinical studies and look further into the
mechanism, says expert on herbal safety Dr Matthias Schmidt.
Dr Schmidt, a consultant on herbal drug safety and member of the International Kava Executive Council, is currently preparing a study plan for a clinical trial. He spoke to NutraIngredients.com in the light of UK authorities' decision to continue banning the herbal, announced this week.
"The only way forward I can see is to provide a clinical trial in the area," he said. Although Dr Schmidt's study plan is aimed at fully restoring the German market, he said: "This will send a tremendous signal to other countries".
He praised the depth of the reports used to form the opinions of the UK's MHRA and FSA, noting just a small number of errors, but said the decision, is "a typical story of benefit of the doubt - and benefit of the doubt is not a scientific question."
"MHRA's motto is to safeguard public health, but the question is whether such a ban may actually have the opposite effect."
Since kava kava was banned in Germany in 2001, Dr Schmidt said he has become aware of cases where people have turned to alcohol or Valium to deal with occasional anxiety and anxiety caused by specific situations, now that they cannot take kava to calm themselves.
"The ban on kava has left a gap that has not been filled," he said.
The UK kava kava market differs from Germany in that licensed products under the remit of the MHRA were intended for bladder discomfort. There may be alternatives approaches for this indication, but unlicensed products aimed at anxiety disorders and foods fall within the scope of the FSA.
In Germany and the US there is not the same duality within the herbals sector. Kava kava is indicated for anxiety disorders.
Although the German authorities ruled the ban on kava kava was inappropriate because the risk of toxicity was low, there has been no proof of efficacy in the indication, for stress-related anxiety, so no products have been licensed to date.
Dr Schmidt explained the problem is that the indication no longer exists in modern diagnostic tools - that is, in the Diagnostic and Statistical Manual of Mental Disorders 4 and the World Health Organisation's International Classification of Diseases.
That is not to say that people do not suffer from it, but it is seen as a chronic disorder requiring treatment of 12 weeks or more. Short-term approaches do not exist.
Dr Schmidt's study plan is at an advanced stage, but as a pharmacist he has need of clinical assistance. Discussions are underway with University professors with an interest in the area.
"The timescale is not known, but we should start fairly soon if we can get the financing," he said. The funding requirements are projected to be in the region of €1 to €1.5m.
He added that there is a need for research on the mechanism of action of kava toxicity, stressing that the toxicity is not obligatory (bound to occur in every instance of ingestion) but idiosyncratic - that is, it occurs in rare and unpredictable cases but by no means all.
"Any food will have some risk of allergy," he said.
He said that worst-case scenario is just one case of liver toxicity caused by kava for every 60 to 125m consumers. The rate of spontaneous liver disease exceeds the rate of kava allergies.
"Do we have to protect consumers from something you cannot prevent? The same thing might happen to them tomorrow just by chewing on a carrot."
Kava kava is a herb from the pepper family with a long history of use in the Pacific Islands, and more recently in Europe, the US and Australia as a herbal medicine and in foods such as tea, cereal products, smoothies and spirit drinks. The European ban on kava has had a "terrific impact" on the South Pacific herb industry.
Fiji, a major kava exporter, saw 30 to 35 per cent of its kava revenues wiped out. Dr Schmidt reported visiting the island in 2004 and seeing first-hand evidence of many small existences wiped out when the markets "broke down without any warning in 2001".
Likewise Vanuatu has no alternative cash crops in the smallholder area, according to Kava Kompanu, and 80 per cent of the population are substistance small holders.
