Enough! or too much. What is 'excessive' kava use in Arnhem Land?

The objective of the study was to describe parameters for use in monitoring health, social and economic effects of kava use in Arnhem Land Aboriginal communities in the Northern Territory (NT). Kava has been used mainly in eight communities (population > 200), and in smaller associated homeland areas since 1982 with a total population of approximately 6800, using cross-sectional description and comparison using data from three kava-using communities. Interview data combined with health worker assessments were compiled using: (1) a sample (n=136) aged 16-34 years in one community in 2001-02; (2) a sample (n=101) aged 16 years and over in 2000 where physical assessments and biochemical and haematological data were also collected; (3) participant-observation in one community (133 people aged 18 years and over) during 1989-91. Kava, supplied illegally, was still being used in Arnhem Land in 2001-02. In 2000 dermopathy characteristic of heavy use, abnormally low body mass index (BMI), low blood lymphocytes and abnormally high gamma-glutamyl transferase (GGT) occurred more frequently with increased kava use. These acute effects emerge at average consumption levels of from 310-440 g/week of kava powder. When kava users in one community began to consume it at an average of 240-425 g/week from mid-1990, 19% of available cash resources were spent on kava with 11% of cash resources leaving the local community economy. The proportion of men drinking kava reached 70% and women 62% from mid-1990, with 20% of the population spending unprecedented amounts of time (14 + hours/week) in activities where kava was consumed. These parameters may be useful to monitor kava's adverse health, social and economic effects. Their association with increased kava use suggests that approaches to minimizing harm from its abuse may begin fruitfully with controlling supply.