Learn how you can give involved with plant conservation
Harmful alkaloids in comfrey (Symphytum officinale) are recognized as a cause of liver disease.
If you were a well-to-do Greek woman living about 3,500 years ago, birth control may not have been a worry. There was an ancient secret that kept women of wealth from unwanted pregnancies. Known as silphium to the Romans and silphion to the Greeks, this herbal oral contraceptive grew in the hills around Cyrene, an ancient Greek city-state in North Africa. Silphion was the principle export of Cyrene, sold in bundles throughout the Mediterranean region, and it commanded a price that exceeded its weight in silver. The problem, however, was that the plant was found only in Cyrene. Attempts to grow it in Greece and Syria failed. Today, the plant survives in only one form—as a crude botanical imprint on rare Cyrenian coins. Silphion, thought to be a member of the carrot family (Apiaceae) and related to giant fennel (Ferula spp.) was harvested to extinction. As the demand for wild-harvested medicinal plants explodes around the world, we must wonder if there is another silphion awaiting a similar fate.
Solutions to an international problem
As the use of herbs has become more popular in the United States and the rest of the world, growing concerns have been raised about the sustainable harvest of wild medicinal plants in habitats stretching from the Gobi Desert to the Swiss Alps. Recognition of the problem was first highlighted at the World Health Organization’s (WHO) Fortieth World Health Assembly, held in 1987. The WHO mandated the need “to initiate comprehensive programs for the identification, evaluation, preparation, cultivation, and conservation of medicinal plants used in traditional medicine.” In March of 1987, an International Consultation on the Conservation of Medicinal Plants was held in Chiang Mai, Thailand. A result of the consultation was the Chiang Mai Declaration,“Saving Lives by Saving Plants,” which recognized, “the urgent need for international cooperation and coordination to establish programs for conservation of medicinal plants to ensure that adequate quantities are available for future generations.”
The WHO estimates that herbal medicines are mostly dried plant materials from 21,000 plant species, primarily collected in low-wage regions of South America, Africa, and Asia. Between 70 and 90 percent of medicinal plants are harvested from natural habitats, with only fifty to 100 species supplied by significant cultivated source material. Since recognition of potential acute and long-term problems with wild medicinal plant supplies fourteen years ago, numerous organizations in both developed and developing countries have stepped forward to address some of these problems.
Each country has its own story. When China first developed intensive programs in the mid-1950s to integrate Traditional Chinese Medicine into public health policy, many Chinese medicinal plants were exclusively collected from the wild. According to Professor Yue Chongxi, serious shortages in supplies of the Chinese traditional drug dang gui (Angelica sinensis), known in the American market as dong quai, were experienced from 1960 to 1963. There was not enough available for clinical use, prompting a search for a temporary substitute until cultivated supplies of dang gui could be established. For a period of several years the European garden herb lovage (Levisticum officinale) was used as a dang gui substitute. Today, dang gui is under large-scale cultivation in at least seven Chinese provinces.
According to Götz Harnischfeger, writing in the Journal of Herbs, Spices and Medicinal Plants, wild plant species could be difficult to cultivate because of naturally developed survival strategies, such as irregular flowering, seed formation, and seed germination times. Other herbs such as mistletoe (Viscum album) have survival strategies that include a symbiotic or parasitic relationship with certain tree species for growth and development. Widely used European herbs such as horse chestnut (Aesculus hippocastanum), haw-thorn (Crataegus spp.), and uva-ursi (Arctostaphylos uva-ursi) may take five years or more to develop into a growth stage in which harvesting can begin, hampering development in agriculture due to risks of relatively long-term investment. Other herbs, such as wild indigo (Baptisia tinctoria), have required more than fifteen years of agricultural research to develop a cultivated supply. Because world demand for wild indigo is only in the neighborhood of 4 to 5 metric tons, with 95 percent of the crop being used by a single manufacturer, the situation thwarts research at the state or national level. The end result is that it may be more economically feasible and practical to harvest from the wild rather than develop high-risk agricultural ventures.
In response to the problem, Harnischfeger produced “proposed guidelines for commercial collection of medicinal plants.” The guidelines call for strict documentation and care to every detail in the collection process. It is unlikely they will ever be followed unless mandated by a government agency at the national level. Still, it is an important step forward in an imperfect world.
Grassroots efforts in the United States
In the United States, attention has been drawn to the issue of medicinal plant conservation by several grassroots organizations such as United Plant Savers (UpS) and the National Center for Preservation of Medicinal Herbs, both with centers in Meigs County, Ohio. Other groups such as the Rocky Mountain Herbalists Coalition have developed guidelines for the wild-harvesting of certain botanicals. The problem has also come to the attention of the U.S. Fish and Wildlife Service, the National Park Service, the U.S. Forest Service, and other government agencies that control natural resources and their utilization. In addition, non-governmental organizations such as TRAFFIC North America, the wildlife trade-monitoring arm of the World Wildlife Fund, have tackled the problem. Some states, such as North Dakota and Montana, have instituted legislation to control the harvest of plant materials on both private and public lands.
United Plant Savers
According to Richard Liebmann, executive director of UpS, “UpS is a non-profit grassroots membership organization whose mission is to conserve, preserve, and restore native medicinal plants and their habitats while ensuring an abundant renewable supply of medicine plants for future generations.”
UpS has created a list of plants at-risk of being over-harvested for the present market and a “to-watch list” of plants that could come under increasing pressure from wild-harvesting in the future. In addition, the organi- zation has purchased a 378-acre “botanical sanctuary” in the heart of the Appalachians in Meigs County, Ohio, just north of the West Virginia border. The sanctuary serves as a research and education center where both scientists and the public can interact with and learn about herbs in their native habitats. Several projects are currently underway at the sanctuary, where graduate students and scientists are looking at the population and reproductive biology of native herbs deemed “at risk,” including goldenseal (Hydrastis canadensis), American ginseng (Panax quinquefolius), and bloodroot (Sanguinaria canadensis), among others. UpS has also created a “Botanical Sanctuary Network,” with members inventorying and setting aside land to identify, preserve, and manage medicinal plants. For more information, see the UpS website at www.plantsavers.org.
National Center for the Preservation of Medicinal Herbs
Near the UpS Sanctuary in Meigs County, Ohio, is the National Center for the Preservation of Medicinal Herbs, an organization founded by Frontier Natural Products Coop- erative and now managed by Rural Action, an Athens, Ohio-based nonprofit development organization. While UpS focuses on preservation, the mission of the National Center focuses on conservation through cultivation. The 68-acre facility includes research beds of more than fifteen species of herbs deemed “critical to cultivate.”
According to research manager Erica Renaud, “We conduct propagation and cultivation studies of woodland natives and other plants defined on the ‘critical-to-cultivate’ list. These studies include propagation methods from seeds and root division, different fertility levels in cultivation systems and their impact on yield and herb quality, different mulching materials, and shade levels impact on growth, yield, and quality.” Renaud says that the information will eventually be published in journals and periodicals for both growers and researchers.
Some of the plants being studied at the National Center include black cohosh (Cimicifuga racemosa), American ginseng, blue cohosh (Caulophyllum thalictroides), goldenseal, wild yam (Dioscorea villosa), and false unicorn (Chamaelirium luteum). The Center’s staff is also researching species that are not native to Ohio, such as the federally listed endangered species Tennessee coneflower (Echinacea tennesseen-sis) and the increasingly rare European alpine species Arnica montana. Go to the Center’s website (www.ncpmh.org) for more information.
An international treaty
While various organizations and institutions are raising issues of conservation and the need to cultivate herbs commercially, it’s ultimately up to governmental authorities to deal with acute problems. When it comes to the importation and exportation of plants or animals with conservation concerns, the United States is a signatory of a treaty called the Convention for International Trade in Endangered Species of Wild Fauna and Flora (CITES). With more than 165 nations signed on, CITES is the treaty that regulates or bans trade in high-profile animal- derived goods such as elephant ivory. Species not allowed in international trade are placed in the CITES Appendix I. CITES also takes action on less visible items such as medicinal plants.
Plants or plant parts listed in CITES Appendix II are controlled and monitored in trade, “in order to avoid utilization incompatible with their survival.” Basically, this means that at the country of exportation, a trail of permits is created to help authorities monitor the status of the species and how much is being traded. In the United States, the Fish and Wildlife Service has jurisdiction over CITES, with cooperation from the USDA and state agencies. The international trade of American ginseng is regulated under the provisions of CITES Appendix II, as are a number of other medicinal plant species including Indian snakeroot (Rauvolfia serpentina) and the Himalayan mayapple (Podophyllum hexandrum), both from India.
Some professionals in the conservation community have criticized CITES as a treaty without teeth. For example, in the case of the Himalayan mayapple, components of which are used in drugs for chemotherapy, the dried root of the plant is covered by the CITES provisions to monitor its export and importation. However, the chemical component sought in commerce can be extracted from the root, and is exempt from monitoring in trade under CITES. It is also up to each individual country’s export authorities to determine what is “detrimental to a species’ survival.” In essence, the listing procedure only brings attention to a conservation problem and does little to assure future adequate supplies of the drug or protect wild populations of the plant.
The case of goldenseal
Perhaps more than any other herb in the last five years, goldenseal has received attention in conservation circles. Most goldenseal is wild-harvested. Because demand has skyrocketed (while supplies have dwindled), the price of goldenseal has skyrocketed, too. In the early 1990s, goldenseal root could be purchased for as little as $8 to $11 per pound, wholesale. In 1995, the wholesale price rose to more than $30 per pound. In 1996, wholesale prices of goldenseal topped $100 per pound. As early as 1884, John Uri Lloyd and Curtis Gates Lloyd noted dramatic declines in wild populations, to an extent as a result of root harvest, but more so as the result of habitat loss through deforestation.
When American ginseng was added to the CITES Appendix II in the mid-1970s, the U.S. federal government mandated that state governments set up systems to comply with the CITES monitoring requirements. However, when goldenseal was listed, the federal government was no longer able to mandate that the states set up a program. Therefore, unlike American ginseng, there are no state programs for goldenseal. CITES compliance for goldenseal is handled on a “permit” basis rather than a “state” regulatory basis. In practice, this means that any company or individual that wishes to export goldenseal must prove to the U.S. Fish Wildlife Service that the plants in the shipment were harvested in a sustainable manner. Because no biological criteria of such proof exists, the net effect is that goldenseal exports have virtually halted since late 1997.
The listing process for goldenseal has had an unforeseen benefit. It has brought the herb industry and the U.S. Fish and Wildlife Service together to deal with this and other problems associated with medicinal plant conservation.
Demand for goldenseal on the domestic market has declined, the price has declined, and consequently, goldenseal is not under the harvest pressure that it experienced just five years ago. If we look at the historical patterns of the goldenseal trade, we can predict that this will only be a temporary situation. The future of goldenseal is still tenuous. When the price of goldenseal went up four or five years ago, many growers began establishing plantings of goldenseal. But with the drop in price, these same growers are beginning to abandon such cultivation efforts.
Writing in an article on goldenseal in a 1904 issue of theJournal of the American Pharmaceutical Association, pharmacist John Uri Lloyd offered this wisdom: “Let me say in closing, that the exorbitant price now demanded for Hydrastis is altogether owing to ordinary man’s improvident disposition and destructive vandalism. The present scarcity is unnecessary, but promises to be cruelly lasting, there being seemingly little prospect of cultivated Hydrastis drifting into market in the very near future, in quantity sufficient to bring the price to a normal condition. Without a doubt, cultivated Hydrastis must command a good commercial return . . . In this connection, I again plead for government and state intervention in such directions as this. If it is proper to preserve a lingering group of bison, or to search the land over for our vanished wild pigeon, why is it not proper to conserve, with the help of the strong hand of authority, America’s valued flora from absolute extermination?”
John Uri Lloyd’s nearly century-old question still awaits an answer.
Comfrey back in the news
Over the past twenty years, comfrey (Symphytum officinale) products have slowly disappeared from the shelves of herb stores and the bulk herb section of co-ops. Comfrey used to be touted for everything from curing wounds to treating lung ailments. Then, in the late 1970s, the romance with the herb began to sour as studies began questioning the herb’s safety. In the late 1960s and early 1970s, various research chemists reported on the presence of pyrrolizidine alkaloids (PAs) in several species of comfrey. PAs, a group of more than 200 alkaloids characterized by a common chemical structure, are widespread in flowering plants. They are especially common to the borage family (which includes comfrey), as well as certain members of the aster and pea families.
Public health concerns over the effects of PAs were highlighted in the mid-1970s after it was reported that wheat contaminated with the seeds of a PA-containing heliotrope species had caused an outbreak of liver disease in thousands of Afghani villagers. Over a two-year period, more than 7,000 people developed severe liver impairments, resulting in many deaths.
In 1975, a similar problem occurred in the Sarguja District of Madhya Pradesh in central India. Food cereals had become contaminated with the seeds of a rattlebox (Crotalaria) species. Nearly seventy people became ill with typical PA poisoning, characterized by liver necrosis, and half of the victims died.
These reports, coupled with an increased understanding of the toxicity of PAs, prompted scientists worldwide to take a closer look at the inherent dangers of PA-containing plant species consumed by humans. Because the borage family is well-known to contain more PAs than any other plant family, it became a target of research. Comfrey seemed to be ingested to a greater extent than any other PA-containing borage family member, so it became the focus of much of the research.
The insidious nature of PA toxicity is that it usually doesn’t produce acute toxic reactions. Rather, PA-induced disease in animals or humans is most likely if plants containing low PA levels are consumed over a relatively long period of time. While PAs were known in comfrey since the 1960s, questions about comfrey’s safety arose in a report by Japanese researchers in 1978.
PAs produce a highly specific condition known as veno- occlusive disease of the liver. A liver biopsy is necessary for diagnosis. In the past, veno- occlusive liver disease was isolated to parts of Jamaica, Africa, and India, where outbreaks of PA poisoning have been more prevalent and better documented. Most American physicians do not encounter the condition, therefore it is rarely recognized. In veno-occlusive liver disease caused by PAs, clotting of the large veins that drain from the liver occurs, completely shutting off the blood flow from the liver.
In the mid- to late-1980s, at least four reports of veno- occlusive disease attributed to comfrey ingestion were published in the medical literature, prompting bans on internal comfrey products in the early 1990s in Canada and severe restrictions on use of comfrey products in Germany.
On July 6, 2000, the U.S. Federal Trade Commission (FTC) announced that a preliminary injunction was agreed to by Christopher Enterprises, Inc. of Springville, Utah, to stop marketing comfrey products for internal uses or on open wounds unless products are free from PAs and are safe.
At the same time, the Food and Drug Administration (FDA) sent a letter to various industry groups and trade associations expressing its concerns over comfrey products, advising that comfrey should not be used as an ingredient in dietary supplement products. The FDA also asked manufacturers to report any adverse events associated with comfrey products.
Because the U.S. government action falls more than a decade behind similar actions by other Western countries, the newfound concern for comfrey comes as no surprise. The FDA’s Center for Food Safety and Applied Nutrition issued concerns about comfrey safety issues in 1993. In June of 1996 the American Herbal Products Association recommended to its members that products containing liver-toxic PAs be labeled “For external use only. Do not apply to broken or abraded skin. Do not use when nursing.”
However, in issuing its injunction, the FTC required Christopher Enterprises’ comfrey products to carry a more hard-hitting statement: “WARNING: External Use Only. Consuming this product can cause serious liver damage. This product contains comfrey. Comfrey pyrrolizidine alkaloids may cause serious illness or death. This product should not be taken orally, used as a suppository, or applied to broken skin...”
Further, this action puts herb manufacturers on notice that the government will not tolerate hyperbolic claims for products it views as unproven and unsafe. (1)
New cranberry study
Researchers at the University of Oulu, Finland, evaluated the effects of a cranberry/lingonberry combination juice (Vaccinium macrocarpon andV. vitis-idaeus) on recurrence of urinary tract infections in women. One hundred and fifty women with a history of urinary tract infections participated in the study for a period of one year. The women were divided into three groups. One group received 50 ml of the juice concentrate (7.5 g of cranberry concentrate with 1.7 g of lingonberry concentrate, dissolved in water) five days a week. The second group of fifty women received a lactobacillus drink five days a week, and the third group of fifty women served as a control. At the end of the study, only twelve recurrences of urinary tract infections were recorded for the cranberry/lingonberry group, while twenty-one cases of recurrence were noted for the lactobacillus group, and eighteen cases were noted in the control group. The researchers concluded that the incidence of recurrent urinary tract infections was significantly lower in the cranberry group compared with the controls.
Cranberry juice is considered a possible alternative to antibiotics in the treatment of urinary tract infections, especially because the use of antibiotics has resulted in increased resistance of bacteria to conventional drugs. (2)
Akerele, O., et. al, Eds. Conservation of Medicinal Plants. New York: Cambridge University Press, 1991.
Foster, S. “Harvesting medicinals in the wild: The need for scientific data on sustainable yields.” HerbalGram 1991, 24:10–16.
Fuller, D. O. Medicine from the wild: An overview of the U.S. native medicinal plant trade and its conservation implications. Baltimore, Maryland: WWF Publications, 1991.
Gladstar, R. and P. Hirsch, Eds. Planting the Future: Saving Our Medicinal Herbs. Rochester, Vermont: Healing Arts Press, 2000.
Harnischfeger, G. “Proposed guidelines for commercial collection of medicinal plant material.” Journal of Herbs, Spices and Medicinal Plants 2000, 7(1):43–50.
Lloyd, J. U. “The cultivation of hydrastis.” Journal of the American Pharmaceutical Association 1912, 1:5–12.
Lloyd, J.U., and C.G. Lloyd. Drugs and Medicines of North America(Vol. 1 Ranunculaceae). Cincinnati, Ohio: J.U. & C.G. Lloyd, 1884–85.
(1) For more details see: http://www.ftc.gov/opa/2001/07/chrisenter.htm
(2) Kontiokari, T., et al. “Randomized trial of cranberry-lingonberry juice and Lactobacillus GG drink for the prevention of urinary tract infections in women.” British Medical Journal 2001, 322:1571.
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