Researchers from the University of Colorado, in Denver reviewed the evidence.

And they come to a conclusion that could cast doubt on the results of most studies of herbals.

First, the details.

• Studies were compared regarding ginkgo biloba extract (GBE) dose, composition, study design, altitude reached, ascent rate, exercise, and risk of acute mountain sickness.
• What’s known about the active components of GBE and their biological effects were considered in interpreting the results of acute mountain sickness prevention studies.

And, the results.

• “Overall, the literature suggests that due to the complexity of GBE, the standardization of the product is inadequate, which likely explains the disparate clinical results.”

The bottom line?
The authors concluded, “The variability in commercially available GBE products makes it impossible to determine whether GBE is truly effective for preventing or ameliorating acute mountain sickness.”

Hmm.

Dr. Dennis Awang of MediPlant Consulting, in British Columbia, Canada tells us, “Physicians [or anyone] who wish to use botanical medicines want to be assured of consistent high quality, efficacious products, and comparable responses from the same dose of an herbal product. However, with herbal products, the identity of the plant’s active principle(s) is/are rarely clearly established. Herbs contain hundreds of compounds.”

“In herbal medicine,” he continues, “an herb’s actions often are recognized long before mechanism of action and active principles are appreciated. Often, numerous constituents are active to different degrees and in various respects. There is relatively little research in this complex area.”

In light of the problem outlined by Dr. Awang, how can we believe the results of any study of herbal medicine in the absence of a pre-study to determine at least the content of the product being tested?

3/15/09 20:23 JR