Questions about Quality Herbal Information
Quality is essential to obtaining the desired results from using any healing remedy — herbal or otherwise. The problem with assessing the quality of herbs is that when we purchase herbs or herbal products, we do not have a good way to evaluate the relative quality of different products.
Even if we grow them ourselves, how can one know that our own herbs, although fresh, are better than what we can purchase? These issues have become a major concern with the growing popularity of herbs and herbal-based products in the United States. The creation of mass markets for these products has brought with it producers and suppliers who sell inappropriate or inferior products right alongside those of high quality. It is virtually impossible for the uneducated consumer to distinguish between quality suppliers and those that are disreputable. While the wide availability of herbal supplements has created a free-for-all market with easy access to products, it has also resulted in confusion and the potential for ultimately short-changing the consumer.
In an effort to promote dialog on these issues, the American Society of Pharmacognosy and the Council for Responsible Nutrition recently held a joint meeting titled “Botanical Dietary Supplements: Natural Products at a Crossroads.” The meeting was held November 8-11, 2001 in Asilomar, California and was attended by approximately 100 representatives from various universities, organizations, the National Institutes of Health, the FDA, manufacturers, suppliers, quality control laboratories and the pharmaceutical industry. The talks and discussion covered topics ranging from private and public initiatives providing clinical information on herbal products and the preservation of traditional ecological knowledge, to agricultural practices for quality assurance, to the regulatory climate of the US in contrast to that in Europe, plus much, much more.
What constitutes good quality when it comes to a plant product? This is a more difficult question than it might first appear to be. Plants are complex materials that vary considerably in their composition. The factors that can lead to composition changes are species of plant, geographic location, growth conditions (e.g., water, light, nutrients), harvest timing (e.g., stage of plant growth and even time of day!), method of harvest and processing (e.g., drying, extracting, storage conditions). To complicate matters further it has been shown that different shoots of the same plant harvested at the same time can have different compositions of materials.
Take echinacea for example. Several species of plant are sold under this same name; however, these plants grow in different ranges across the US and samples from different species or locations show differences in the relative amount of various materials present in the plant. One way preparations are standardized (those that are standardized at all) is using the level of a marker compound, chicoric acid, present in the plant. However, even if the marker compound does account for some of the biological activity associated with the plant, there are many more compounds present in the plant that may be important for the beneficial effects of the plant. The danger of relying only on a marker compound is that the producer may optimize growing conditions to give the highest level of marker compound. Those conditions may not be the best for producing the most beneficial plant material. The best time to harvest echinacea, based on traditional knowledge for instance, is immediately past the peak of the bloom. The peak of certain marker compounds is at a different time, so the marker by itself is not the best indicator for producing the best material. In Europe, where standardization and control is more stringent, some manufacturers make their materials such that the overall profile of plant components is similar from batch to batch, much as a whiskey distiller will blend their batches to produce a consistent product.
Further complicating quality assurance and standardization beyond variations in composition of the herb itself is the problem of contamination. Botanical contaminants are the result from misidentification of the plant material, as mentioned above, as well as intentional adulteration. There are also biological contaminants (e.g., bacteria, fungi, molds) and environmental contaminants (e.g., metals, pesticides, insects). In order to ensure quality, it is important to combine the most reliable traditional knowledge with good agricultural practices and well designed analysis measures in order to assure consistent quality products.
Wild harvesting is another area of potential concern, both in terms of quality and environmental impact. For many medicinal plants, the wild populations are not well documented and virtually no information is available on the impact of various harvesting schedules on the quality of the herb harvested and the sustainability of commercial harvesting pressures. The US Fish & Wildlife Service is facilitating such research so that it can make informed regulations through its CITES office on plant restrictions (e.g., ginseng and golden seal). Another problem with wild harvested materials is plant misidentification. Plants are often misidentified or two species of a plant may grow together and be harvested as one type of plant. Black and yellow cohosh, for instance, grow together and are likely to be harvested together. Upon drying, the yellow cohosh root turns black and is indistinguishable from dried black cohosh root.
Cultivation would seem to be the solution to both the quality and quantity demands of the public, however, it is important to first preserve the traditional cultural knowledge associated with the plant. This knowledge is essential to providing the optimal environment for the plant and for the best handling, processing and use of the plant. When done correctly, cultivated materials can be produced that faithfully represent wild harvested materials in terms of complexity and composition of natural components, although possibly not in quantities that would completely satisfy mass markets.
The preservation of traditional ecological knowledge is being undertaken by a variety of public and private groups worldwide. One remarkable success story comes from Samoa. Traditional Samoan healers used a tea from the bark of a tree, Homoluthans nutans, to treat viral infections. Researchers at the National Tropical Botanical Garden in Hawaii investigated this bit of traditional knowledge further and discovered a novel compound, prostatin, that was licensed from the National Cancer Institute by the AIDS Research Alliance and in development for treating AIDS. This compound acts in a way no other AIDS treatment does. It activates all the known sites where HIV hides in the human body, which will allow for a clearing of the virus from the body. In addition to a new potential tool in the fight against AIDS, a percentage of the profits will go to the Samoan government, village and the traditional healers’ descendants. Another story emphasizing the importance of traditional knowledge is “cat’s claw.” In 1959, Austrian scientists learned of a medicinal plant effective for treating rheumatoid arthritis. It took these scientists 25 years to learn from traditional healers in Peru that of at least eighteen plants that are called “cat’s claw” only one is traditionally used for treating arthritis. Careful identification of the correct plant is critical for being able to collect the effective material.
Other positive developments are the numerous efforts promoting public education regarding botanicals (e.g., American Botanical Council, www.herbalgram.org), and those efforts to conduct controlled clinical trials validating the applications and dosing required to effectively use various plant products. The National Institutes of Health have established four Dietary Supplement Research Centers at the University of Illinois, University of Arizona, Purdue University and UCLA. Each is focused on exploring different plants and their applications and each center is funded by the government. Ultimately, the best quality assurance can come from clinical trials that establish the effectiveness and optimal dose for a particular well characterized formulation of a plant product.
There is a growing recognition that quality-assured and holistic approaches to the cultivation and utilization of herbs is critical to maximize their healing potential and success. Traditional knowledge coupled with environmentally sound harvesting practices and modern analytical techniques provide a cohesive body of knowledge more reliable than what any one approach can provide. Regulation, either from the government or self-imposed by the industry, will ultimately be necessary to raise the level of quality and consistency of the products available, and build confidence and acceptance for the use of herbal products in the future.
Dr. Krstenansky is co-founder and CEO of HubaTech, LLC, a research company developing methods to improve existing natural products using natural processes. He is a drug designer with 16 years experience in the pharmaceutical and bioprocess industry, as well as a mycophile and grower of mushrooms.