What makes herbs tick? It’s a question that will be asked—and answered—in new and different ways in 2001 and the years to come.
Herbal medicine has come of age in the past five years, moving from the health-food market to the mass market. Once-obscure plants known only to herbal insiders are now household words. Major players in the pharmaceutical world have either bought their own lines of herbal medicine or are beginning to produce them. But as the market has matured, the holes in herb research have come into focus more clearly, often resulting in controversy and confusion.
For example, scientists may know about one active chemical component of an herb. But herbs are complex living organisms, made up of many interacting chemicals. If one of their constituents has an effect on the human body, chances are there are several others yet to be discovered. Even when the benefits of an herb are known—such as echinacea’s ability to reduce cold and flu symptoms—mysteries may remain about how the herb is metabolized in the body.
When research does exist on an herb, experts may—and frequently do—disagree on the conclusions that can be drawn.
The type of research being done on herbs also is changing. When herbs are effective, they still offer the potential to radically change the world of medicine. Such changes also carry the potential for great profit. The world is on the brink of a new era of herb research that will bring new technologies and new partnerships to bear on the science of botanical remedies, answering questions that have long puzzled experts.
The case of echinacea
Most people now know about echinacea—it’s the botanical poster child of herbal medicine, the pink wildflower whose root compounds are used to prevent and treat colds and flu. The past decade has seen dozens of new chemical, pharmacological, and clinical studies on it. But according to the world’s leading echinacea researcher, Rudolf Bauer, Ph.D., at Heinrich Heine University in Düsseldorf, Germany, this well-known remedy is still guarding some important secrets.
Speaking before an international congress in Zurich, Switzerland, last September, Bauer emphasized the need to better understand what type of echinacea product works best and how much of it users need to take. Controlled, clinical studies on these two issues haven’t produced definitive answers.
“One problem is that many echinacea extracts are not well defined chemically, making comparison between products difficult,” Bauer said. In other words, scientists haven’t identified all of the chemical constituents that make up these extracts, nor have they identified which ones provide the health benefits. That’s not unusual for an herb or herbal extract; according to Stefan Gafner, Ph.D., a Swiss-trained medicinal plant researcher at Tom’s of Maine, a single plant may have as many as 10,000 chemical constituents.
Among the echinacea mysteries Bauer would like to see solved are the following.
1. What chemical compounds are present (or absent) in different echinacea products, for example, tinctures versus capsules, or E. purpurea versus E. angustifolia?
2. Are there additional unknown compounds that play a role in echinacea’s immune-stimulating activities?
3. How much of these compounds can the body actually absorb? (This is known as the compounds’ bioavailability.)
Although these questions remain, Bauer reported on research that sheds new light on this herbal remedy. Initial research attributes significant antioxidant activity to echinacea. Another recent study provided some evidence that the plant’s compounds may be useful in conjunction with other treatments for HIV- positive patients.
Bauer cautioned, however, that herb users should not read too much into these initial reports. “These laboratory studies need to be further evaluated to establish their relevance to therapeutic effects,” he said.
One of the drawbacks to herbs becoming better known is that their therapeutic effects become simplified to the point of inaccuracy. When echinacea became established as the herb to take for colds and flu, its other uses were eclipsed.
At the same congress, Jen W. Tan, M.D., medical director of Bioforce UK in Irvine, Scotland, discussed other uses of echinacea. At the Naturopathic Clinic in Auchenkyle, Scotland, Tan and 11 other doctors see more than 1,000 patients a week. The team there has used echinacea clinically for more than thirty-five years to treat a host of conditions including chronic fatigue syndrome, chronic or recurrent bacterial infections, chronic bronchitis, emphysema, sinusitis, ear infections, and bladder infections. They’ve also used it for fungal conditions, including athlete’s foot, ringworm, and candidiasis, as well as eczema.
Clinical studies on echinacea’s benefits for many of these conditions are still lacking, says Tan, but “we have found no evidence for limiting its use to short periods of time,” he adds. In the past, many practitioners were recommending that people use echinacea for no longer than two weeks at a time, with at least a one-week break between courses of treatment.
Big studies, big funding
As worldwide clinical use and research on echinacea continues, the fabric of what is known about the herb slowly becomes more whole. In the United States, broad governmental strokes will build that fabric a bit more quickly for a number of medicinal herbs.
When Congress passed the Dietary Supplement Health and Education Act of 1994 (DSHEA), the same legislation created the Office of Dietary Supplements within the National Institutes of Health (NIH). For fiscal year 2001, the Office of Dietary Supplements’ funding is more than $100 million. The office closely coordinates its work with the National Center for Complementary and Alternative Medicine, also part of the NIH.
This unprecedented alliance allows public funding of research to explore herbs and other dietary supplements and the ways that consumers are using them. The result: the creation of four new centers for research on dietary supplements. The centers each have about $1.5 million per year for five years to study botanicals and their role in health. The centers are at the University of California, Los Angeles; the University of Illinois, Chicago; Purdue University in Fort Wayne, Indiana; and the University of Arizona in Tucson.
The research at the University of Illinois is under the direction of renowned pharmacognosist Norman Farnsworth, Ph.D., one of the most respected medicinal plant researchers in the world. It will focus on herbs for women’s health that scientists have chosen because there is a need to identify the active constituents, develop standardization procedures, and confirm safety and effectiveness through clinical studies.
Farnsworth’s group will first study black cohosh (Cimicifuga racemosa) and red clover (Trifolium pratense), two herbs that have long been used to relieve menopausal symptoms. The research team will discover or verify the chemical components and microscopic details necessary to assure batch-to-batch consistency of a standardized extract. Once that work is complete, the extract will be submitted to the Food and Drug Administration (FDA) for approval of a clinical study, much the way a new drug under investigation would apply for approval.
A phase I study will enroll sixty women to assess the extract’s initial safety. If the extract passes safety tests, it will move forward to a phase II study. In that stage of the research, 120 women volunteers will participate in a study of the ability of each herb to alleviate symptoms such as hot flashes. This clinical trial phase is expected to last for four years. German studies of these herbs have come under fire for lasting only several weeks.
Farnsworth’s group will examine other traditional women’s herbs: chaste tree (Vitex agnus-castus), used for premenstrual syndrome; dong quai (Angelica sinensis) the most popular Chinese herb for women’s health; hops (Humulus lupulus), whose sedative and estrogenic qualities have been both confirmed and denied by research; Asian ginseng (Panax ginseng), known as a fatigue and anxiety reducer; valerian (Valeriana officinalis), a sedative and sleep aid; and cranberry (Vaccinium macrocarpon), commonly used for urinary tract infections.
Beyond the Chicago studies
The world is on the brink of a new era of herb research that will bring new technologies and new partnerships to bear on the science of botanical remedies, answering questions that have long puzzled experts.
Connie Weaver, Ph.D., will direct the NIH-funded research at Purdue, focusing on the effects of polyphenols. These compounds, known to have antioxidant effects, are common components of soy, grapes, green tea, and a number of herbs. Weaver’s group will focus on other health benefits these compounds may have, especially in the prevention or treatment of heart disease, cancer, and bone metabolism.
Barbara Timmermann, Ph.D., will direct the research at the University of Arizona. The group there will focus on commonly used Ayurvedic herbs, including ginger (Zingiber officinale), turmeric (Curcuma longa), and boswellia (Boswellia serrata). First researchers will study what chemical compounds are in the herbs, and how those compounds interact. Later, clinical studies will evaluate the herbs in the treatment of arthritis and other chronic inflammatory diseases, such as asthma.
Research at the University of California, Los Angeles, directed by David Herber, Ph.D., will focus on how yeast-fermented rice may help with cholesterol reduction; the use of green tea and soy extracts for inhibiting tumors; and the use of St. John’s wort for mild depression.
The research of Farnsworth and his colleagues takes herb research to a new level; whether the results are negative or positive, they will likely be scientifically definitive. Putting chemical, pharmacological, and clinical studies under one roof should set a new standard for the herb industry to follow. For further information on the NIH studies, see these websites:
Office of Dietary SupplementsNational Center for Complementary and Alternative Medicine
These government studies are far from the only research happening in the United States this year. Large-scale clinical studies are currently underway on St. John’s wort for treatment of depression (at Duke University in Durham, North Carolina), and saw palmetto (Serenoa repens) for benign prostatic hyperplasia (at the University of California, San Francisco). This research will provide a better picture of how the herbs work, because the studies involve larger populations than ever previously used in the United States.
Where German research is heading
To practitioners, Germany is known as the home of herbal research because of its Commission E, a body similar to the United States’ FDA. The Commission E reviews available research and history of use of herbal medicines and approves them for use by prescription or over-the-counter.
Aldolf Nahrstedt, Ph.D., of Wesfälische Wilhelms University in Munster, Germany, says that interest in plant-derived medicines has only intensified there. Among an assortment of new findings:
• Arnica (Arnica spp.), used traditionally to treat bruising and contusions, has been found to contain components whose molecular activity in treating bruising is known, providing scientific backing for use of arnica preparations.
• Compounds in black cohosh bind to estrogen receptors, providing the same kind of justification for the herb’s use for menopausal symptoms.
• Common English ivy (Hedera helix) has traditionally been used in cough medicines in Europe. Recently, European researchers have discovered the compounds responsible for its antispasmodic effects that help calm coughs. Nahrstedt notes that new research must be done on the herb’s active constituents, their interactions, their bioavailability, and how they work in the cells of the body.
Where it’s all going
The value of the new research is in the details—details that will help ferret out how chemical components in commonly used herbs interact with one another to create the benefit consumers expect from the plant. Many of the new studies are focusing on mechanisms of action, namely, how the herb enters the bloodstream, is metabolized by the body, and produces its healing effects.
Once these studies are completed, the challenge will be to make them available to health-care providers—pharmacists, doctors, and nurses who work in the front lines of treating patients. But the ultimate test will be how consumers react: whether herbs can regain the trust lost in the blitz and the backlash to realize their potential as the medicine of the new millennium.
Steven Foster is lead adviser of Herbs for Health. An author, photographer, and consultant specializing in medicinal plants, he was also technical consultant to The Herbal Drugstore (Rodale, 2000). He makes his home in Fayetteville, Arkansas.