25 July 2005
Fresh Doubts Over Herbal Remedies
The July issue of Medicine provides some interesting insights into the effectiveness of herbal remedies following a trial to examine the effects of kava and valerian, used to treat anxiety and insomnia. The Internet-based trial, conducted by researchers from the University of California-San Francisco, included nearly 400 participants from across the United States. Interestingly, the study is the first randomized, controlled clinical research trial to be conducted entirely over the Internet.
Bradly P. Jacobs and co-researchers recruited potential subjects, who self-reported anxiety and insomnia, through e-mail and websites. One group of patients received kava plus a valerian-placebo and one group received valerian plus a kava-placebo, while a third group received double placebos. After a month of treatment, subjects completed follow-up questionnaires which suggested that the herbal extracts were no more effective than the placebo in reducing the symptoms they were intended to treat. In fact, anxiety scores decreased by 25 percent for patients taking placebo, compared to about 21 percent with either kava or valerian. Similar effects were also noted with the insomnia treatment.
Anxiety and insomnia often occur together and kava and valerian are among the most popular herbal remedies used, despite the lack of scientific studies to support their effectiveness. The new findings question the benefits of kava in reducing anxiety, or valerian in improving sleep, as the results appear no better than with the placebo treatment. 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" the researchers concluded.