Quelle: The American Journal of Medicine and Researchers from the University of California, San Francisco; the San Francisco Veterans Affairs Medical Center
 

Eine erste randomisierte Doppelblindstudie belegt, dass eine in China weit verbreitete und oft angewandte Mischung aus zehn unterschiedlichen chinesischen Kräutern die ihr zugeschriebene Wirkung nicht hat.

   Evaluating Chinese Herbal Medicines with
   Placebo-Controlled Studies

October 17, 2003
Do Chinese herbal medicines improve general health, when evaluated in Western-style, placebo-controlled trials? In a study published in the current issue of The American Journal of Medicine, researchers from 3 institutions in the United States and a Beijing, China hospital found little effect.

Sales of herbal medicines, including traditional Chinese herbs, are now estimated to be more than $4 billion annually. Longevity Treasure (Enwei Pharmaceutical Company) is a proprietary extract composed of 10 Chinese herbs believed to increase longevity, quality of life, energy, memory, sexual function, and qi, the Chinese concept of vital energy that is important in general health.

Because the product is used widely in China, Stephen Bent, MD, writes, We sought to determine whether regular use of this product would lead to improved health in elderly Chinese adults. He continues, We attempted to measure changes in both a standard Western measure of quality of life (the SF-12 scale) and an Eastern measure (the qi scale).

Researchers from the University of California, San Francisco; the San Francisco Veterans Affairs Medical Center; The Andrus Gerontology Center of the University of Southern California; and the Peking Union Medical College Hospital, enrolled 237 residents of Beijing, China in this study. All patients were at least 60 years old and had reported decreased energy, memory or sexual function. In a double-blind, randomized study, patients took four tablets of a Chinese herbal formula or a placebo, three times a day for 30 days.

Patients taking the herbs had a small, two-point improvement in a questionnaire measure of mental health compared to patients taking placebo, but no improvement in physical performance, memory, sexual function, or qi.

As a comparison, patients recovering from depression achieve an approximately ten-point improvement in the same mental health scale. Dr. Bent notes that, when a study includes so many different outcome measures, a small benefit in only one of the outcomes may indicate a chance finding, rather than a true benefit from the herbs.

However, the study does demonstrate that Chinese herbs can be evaluated with high-quality randomized, placebo-controlled trials, which can examine both Western and Eastern concepts of health. Qi is an important concept of health that has been present in Chinese culture for thousands of years, says Dr. Bent. One of the key findings of this study is that, with a collaboration of Chinese and American institutions, we can begin to evaluate this important measure of health. Dr. Bent believes that the health claims of Chinese herbal medicines, even though they involve different types of benefits such as improvements in qi, should be rigorously tested.

The fact that Chinese herbs have a long tradition of use does not prove their safety and efficacy. These products can and should be tested with the same techniques used to evaluate drugs: if there are important beneficial effects on qi or other health measures, we should be able to find them.

The study is reported in A Randomized Controlled Trial of a Chinese Herbal Remedy to Increase Energy, Memory, Sexual Function, and Quality of Life in Elderly Adults in Beijing, China

by Stephen Bent, MD, Ling Xu, MD, Li-Yung Lui, MA, MS, Michael Nevitt, PhD, Edward Schneider, MD, Guoqing Tian, PhD, Saishan Guo, MD, and Steven Cummings, MD, MPH.The article appears in The American Journal of Medicine, Volume 115, Number 6,