Scientists attending a conference on complementary medicine last week said a ban on the controversial herbal medicine kava may be an an over-reaction to an uncommon side effect.
Scientists at the annual complementary medicine conference of the UK's Peninsula Medical School said that just 70 cases worldwide have been identified, showing that the risk level of liver damage is comparable to that of the conventional drug Valium. The total health risk (including dependency) is likely to be much smaller than that of benzodiazepines, said the complementary medicine experts.
Kava is used by many people as a sedative, a muscle relaxant or a diuretic but the UK's Medicines Control Agency looks set to recommend a total ban on the herb following reports that it may, like Valium, cause damage to the liver in rare cases. Other countries, such as Germany, France and Switzerland have already banned kava.
But Professor Edzard Ernst, chair of Complementary Medicine at Exeter University, said that a total ban goes too far."Kava is proven to be effective in treating anxiety and, looking at the total risk, it is safer than synthetic drugs. If we are going to ban kava today, then we should have banned Valium twenty years ago.
"The public is entitled to protection from dangerous and toxic treatments whether they are complementary or conventional, and we need to investigate these recent reports of liver damage associated with kava," he continued. "But it may be counter-productive to ban an efficacious medicine on the basis of criteria that seem to be harsher than those used to licence conventional, artificial drugs."
The Medicines Control Agency is expected to make its recommendation to the UK Secretary of State for Health in the near future.
The Peninsula Medical School's 9th Annual Symposium on Complementary Medicine last week attracted 150 delegates from 12 countries to discuss all types of complementary medicine.