Kava, used for generations in traditional ceremonies by Pacific islanders, is an effective and safe treatment for anxiety, university researchers say.
People with "chronic high levels of anxiety" feel less worried and, in some cases, less depressed during a 60-person trial undertaken at the University of Queensland (UQ).
"We've been able to show that kava offers a natural alternative for the treatment of anxiety and, unlike some pharmaceutical options, has less risk of dependency and less potential of side-effects," said lead researcher Jerome Sarris, a PhD candidate from UQ's School of Medicine.
"We also found that kava had a positive impact on reducing depression levels, something which had not been tested before."
Anxiety levels were reduced in trial participants who took five tablets of kava daily, as opposed to a placebo group that took dummy pills.
Critically the study's participants did not show any signs of potential liver damage -- contrary to concerns that prompted European, British and Canadian authorities to ban kava sales in 2002.
Kava products sold in those countries were based on ethanol or acetone extracts of the kava plant, Mr Sarris said, not the water-soluble extracts used traditionally by Pacific islanders and approved for sale in Australia.
"Our study used a water-soluble extract from the peeled root stock of a medicinal cultivar of the plant, which is approved by the Therapeutic Goods Administration," Mr Sarris said.
"When extracted in the appropriate way, kava may pose less or no potential liver problems (and) I hope the results will encourage governments to reconsider the ban."
Kava contains the psychoactive agent "kavalactones" and a traditional ceremony involves pulping roots of the plant and then drinking it mixed with water.
It is said to have a tranquillising effect but without the loss of mental clarity associated with alcohol.
Vanuatu and Fiji are among the world's largest producers of kava, and Mr Sarris said the loss of major export markets had delivered a significant blow to the islands' economies.
"Allowing the sale of kava in Europe, the UK and Canada would significantly enhance Pacific island economies, which have lost hundreds of millions of dollars by not being able to export the plant over the past several years," he said.
Kava tablets can be purchased in Australia from pharmacies and natural health stores. There are volume restrictions on its importation in a powdered form.
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