BACKGROUND: Of the available medications for treating alcohol-related problems, none are universally effective, and all have side effects that may limit their use. Extracts of kudzu containing a variety of isoflavones have been shown to reduce alcohol drinking in rats and hamsters.

METHODS: The present study was designed to test the efficacy of a kudzu extract in a clinical population. Male and female "heavy" alcohol drinkers were treated with either placebo or a kudzu extract for 7 days and then given an opportunity to drink their preferred brand of beer while in a naturalistic laboratory setting. Participants served as their own controls, and order of treatment exposure was counterbalanced. Drinking behavior was monitored by a digital scale that was located in the top of an end table.

RESULTS: Kudzu treatment resulted in significant reduction in the number of beers consumed that was paralleled by an increase in the number of sips and the time to consume each beer and a decrease in the volume of each sip. These changes occurred in the absence of a significant effect on the urge to drink alcohol. There were no reported side effects of kudzu treatment.

CONCLUSION: These data suggest that an extract of this leguminous plant may be a useful adjunct in reducing alcohol intake in a naturalistic setting.