Newswise — Two popular herbal remedies—kava, commonly used for anxiety, and valerian, used for insomnia—are no more effective than an inactive placebo, concludes a study in the July issue of Medicine.
Dr. Bradly P. Jacobs and colleagues of University of California-San Francisco performed an innovative Internet trial to evaluate the effectiveness of kava and valerian. Potential subjects who reported anxiety and insomnia were recruited through e-mail and websites. The final study included 391 participants from 45 states.
By mail, one group of patients received kava plus an inactive valerian-placebo and one group received valerian plus kava-placebo; a third group received double placebos. After four weeks of treatment, subjects used a secure website to complete follow-up questionnaires.
The herbal extracts were no more effective than placebo in reducing the symptoms they were intended to treat. Anxiety scores decreased by 25 percent for patients taking placebo, compared to about 21 percent with either kava or valerian.
The effects on insomnia were also similar—in all three groups, insomnia scores and time to falling asleep decreased by about 50 percent. The results were comparable across patient subgroups, such as those with higher vs lower depression scores.
Most side effects were comparable between groups, although patients taking valerian had a higher rate of diarrhea. The study was performed before recent safety warnings concerning liver damage related to kava. However, none of the patients taking kava reported any liver-related side effects.
Anxiety and insomnia are common symptoms that often occur together. Kava and valerian are among the most popular herbal remedies, with annual sales of over $28 million in the United States alone. However, few scientific studies have been performed to evaluate their effectiveness.
The new results question the true benefits of kava in reducing anxiety, or valerian in improving sleep for people with insomnia. Although many people trying these herbal remedies will feel better within a few weeks, the results appear no better than with inactive placebo treatment. Within the confines of a clinical trial environment in which people are highly motivated to seek relief from their medical condition, any improvements "may not be attributed to the biological effects of kava or valerian, and if attributable are no greater than the effect of placebo" Dr. Jacobs and colleagues conclude.
The study is the first randomized, controlled clinical research trial to be conducted entirely over the Internet. The "direct-to-participant" method used for the study included measures to confirm that the participants were who they claimed to be and were not providing misleading information on outcomes. Internet studies may provide a valuable new approach to enrolling appropriate research subjects quickly, efficiently, and at lower cost than with traditional research designs.
Medicine provides insight from leading scholars about the latest results in clinical investigation. Relevant to both hospital and office practice, the journal includes analytical reviews of Internal Medicine, Dermatology, Neurology, and Pediatrics topics. The journal is published by Lippincott Williams & Wilkins of Philadelphia, PA, and is available online at http://www.md-journal.com.
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