Researching botanical medicines for safety and efficacy

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Researching botanical medicines for safety and efficacy

by Theresa Johnston on Monday, April 5, 2010 - 2:41am

Fredi Kronenberg croppedWhen it comes to hot flashes, many American women swear by herbal remedies such as black cohosh. But the U.S. botanical medicine industry still has a long way to go in terms of research and product quality control, says Fredi Kronenberg, Ph.D., a women’s health expert and 2008-09 faculty research fellow at the Michelle R. Clayman Institute for Gender Research.

“When this country began to focus on “wonder drugs” [in the 1950s], it left herbs behind,” she notes, “but Europe maintained its botanical tradition clinically, and in research.” As a result, the medical landscape is quite different in Germany today; doctors learn about botanicals in medical school, some 40 percent of prescriptions are written for botanicals, and herbal products are government approved. “They do high quality research and produce high quality products.” In Asia and many other parts of the world, herbal medicines are still the primary part of health care.

A native of New York, Dr. Kronenberg has been interested in women’s health issues ever since she was a graduate student at Stanford in the late 1970s. Her expertise in herbal medicine grew out of her experiences as a postdoctoral researcher and faculty member at Columbia University. “I was studying the physiology of hot flashes,” she recalls, “and many of my subjects were coming into the laboratory saying they were taking various herbs and that some of them worked. I looked to see whether there had been any research on these products. There hadn’t.”

Botanical MedicineEventually, Dr. Kronenberg became the founding director of Columbia’s Richard and Hinda Rosenthal Center for Complementary & Alternative Medicine, one of the first programs at a major medical school in this country to facilitate and conduct rigorous scientific investigation in what was then a new field.  Completed at Stanford last year as part of her Clayman fellowship, Dr. Kronenberg’s latest work, Botanical Medicine: From Bench to Bedside, co-edited with Raymond Cooper, Ph.D., is a handbook for scientists interested in conducting botanical research.

At a Clayman Institute book-signing last fall, Dr. Kronenberg described some of the challenges facing investigators who want to study herbal medicine. “The initial problem is that it takes some knowledge of the field to find high quality products [to test],” she explained. For example, she and her colleagues recently conducted a study of black cohosh, an herb native to the eastern U.S. Their findings? Forty percent of the products purchased in American drug- and health-food stores were found to contain the wrong species of plant – a Chinese variety not used traditionally for hot flashes.

And don’t even get her started on new commercial “formulas” for menopause. “Many of these women’s health products drive me crazy,” she says. “In order to distinguish theirs from other products, companies put something different in their products. So now you have a ten-herb supplement that claims to be an ‘all-natural menopause herbal supplement that balances the female system.’” Kronenberg asks, “What are they balancing?” It is not clearly stated in the product description. “They list ten herbs on the box and don’t tell you the plants’ Latin names or part used or the amounts of each. So you don’t know the content, much less if there is enough of anything to have biological activity. What they’ve done is take every herb that’s ever been mentioned in some book in the same sentence as the word ‘woman’ and that’s what they put in the product.”


“This is not a long-standing traditional Chinese medicine formula that has stood the test of time,” adds Kronenberg.  “To be fair to the good quality companies, some of the mixed herb products are designed thoughtfully, with rationale behind the combination and amounts of herbs included.” The challenge for consumers is to be able to differentiate between long-standing or tested formulas and the more haphazard formulations.

Women are the largest consumers of health care services in general, and they also use more complementary and alternative treatments than do men, says Dr. Kronenberg. This is true throughout the life cycle. Women use alternatives for themselves, their children and their spouses.  “Many want to avoid pharmaceutical drugs during pregnancy, or they want to try more gentle options for their children, hopefully to avoid, or before resorting to more powerful drugs; or they want to avoid the potential harmful effects of long-term hormone therapy at menopause.” Dr. Kronenberg believes that “it behooves the research community to study the botanical therapies that are used by millions of people, so as to provide the evidence of safety and efficacy that clinicians and the public want and need.”

Despite her concerns, Dr. Kronenberg has high hopes for the field, particularly if the FDA starts enforcing some of the regulatory power they already have. “And, if they can improve the quality of the manufacturing,” she says, “that’s a majority of the problem solved.” In the meantime, she plans to stay at Stanford and continue studying the still-mysterious physiology of hot flashes. She also is working with colleagues to expand the integrated medicine program at Stanford.