April 2, 2001 – When there is more than one research study that has studied the exact same subject with the same research protocols, researchers may perform what is called a “meta-analysis”, that is, combining the results of all previous research and draw an overall conclusion. These meta-analyzes thus give more significant statistical results since they relate to a larger number of data.
This is what researchers at the University of Exeter in the United Kingdom did by analyzing the results of three randomized, double-blind, placebo-controlled studies that investigated the effects of a kava kava extract on anxiety. All three studies used the same anxiety scale (the Hamilton Rating Scale for Anxiety or HAM-A) and the same kava kava preparation, a standardized 100 mg extract yielding 70 mg of kavapyrones.
The three studies, which lasted for up to 24 weeks, confirmed that taking 100 mg of kava, 3 times a day, resulted in a drop of up to 10 points on the HAM-A scale while placebo no did not have such a marked effect in any of the studies. This meta-analysis confirmed the results of the most important clinical research (Volz et al. 1997) carried out to date on the effects of this plant.
With conventional treatment with benzodiazepines accompanied by serious side effects including addiction, drowsiness and memory loss, the researchers conclude that kava extract is a valid treatment for anxiety disorders.
HealthPassport.net
Pittler MH, Ernst E. Efficacy of kava extract for treating anxiety: systematic review and meta-analysis.J Clin Psychopharmacol. 2000 Feb; 20 (1): 84-9
Volz HP, Kieser M. Kava-kava extract WS 1490 versus placebo in anxiety disorders – a randomized placebo-controlled 25-week outpatient trial.Pharmacopsychiatry. 1997 Jan; 30 (1): 1-5
