In 1991 previously healthy young women in Brussels started showing up at clinics with advanced kidney damage. An inquiry revealed that they had all attended the same weight-loss program and, due to a mix-up, had received the Chinese herb Aristolochia as part of the regimen. More than 100 women developed irreversible kidney damage requiring dialysis or transplantation, and a high percentage went on to develop cancer of the upper urinary tract.
Had it not been for the unusual nature of the outbreak and alert clinicians, the incident might well have gone unnoticed. As it turned out, the Brussels cluster dramatized in an unprecedented way the previously unacknowledged threat that can be posed by herbal remedies.
In the 25 years since the Brussels outbreak, we have learned a great deal about the use and harmful effects of toxic herbs. This knowledge, however, has not translated into policies to reduce the harm caused by botanicals. Instead, the World Health Organization has launched an ambitious program that flies in the face of the scientific evidence the organization demands elsewhere and shamelessly promotes the use of traditional medicine, including herbal treatments, that could be dangerous.
The problematic program actually dates from the early 2000s, when WHO launched its first “traditional medicine strategy.” In 2013 WHO’s Director-General Margaret Chan announced an extension of original initiative to foster the integration of traditional medicine into health care systems as a way to improve health in developed as well as developing countries while limiting health care costs. In the resulting 76-page brochure, “Traditional Medicine Strategy,” WHO touts the growing interest worldwide in traditional medicine as well as its increasing economic importance. The report pays lip service to the need for attention to the “safety and efficacy” of traditional medicine and refers in a generic way to “risks” associated with its use. However, it fails to cite a single example of the types of damage associated with the use of herbs or to refer to the extensive evidence of adverse effects. Furthermore, WHO ignores the inconvenient fact that rigorous assessments of herbal remedies show little or no support for the claimed benefits. (Though the term “traditional medicine” encompasses a variety of practices, which vary in different countries, of greatest concern is the use of herbal remedies, which can cause direct harm and are often not tested for efficacy.)
How can an organization dedicated to improving the health of the world’s populations in the 21st century turn a blind eye to the medical evidence on herbal remedies? The answer to that question is hidden among numerous factors that influence the use of these products, including the commercial, cultural, and political forces at play. The short answer is that when it comes to traditional medicine, WHO seems to ignore its insistence on evidence-based science in favor of traditional and local support for these remedies based on considerations quite apart from the science.
Herbal remedies are widely used throughout the world, particularly in regions where there is a strong culture of folk healing and where access to modern health care is limited. In such cultures, the authority of tradition and a long history of use have ensured that the safety and efficacy of herbal products are largely taken for granted. However, just because something has been used for centuries doesn’t mean it is safe and effective. In many of these places, WHO should be calling for rigorous evidence-based assessments of these remedies, rather than accepting conventional wisdom.
In the U. S., botanicals are marketed along with other dietary supplements as “alternative medicine.” Many consumers assume that these products are safe because they are advertised as “natural” and that they’ve been tested and approved by the Food and Drug Administration. Neither assumption could be further from the truth—these types of supplements have not been even cursorily, let alone systematically, investigated for adverse effects, never mind benefits. They’re allowed to be sold only thanks to the 1994 passage of the Dietary Supplement Health and Education Act, which opened the floodgates to the unregulated marketing of “dietary supplements.” This ruling meant that supplements, unlike drugs, do not have to undergo testing before they are sold to consumers. Rather, they are assumed to be safe until proven otherwise. The FDA has the unrealistic burden of identifying and recalling dangerous supplements only after they have caused harm.
What we have learned about herbal remedies and other traditional treatments is that they’re not as safe as we think. To give just a few examples of what has been found when the substances are subject to review:
- Data from a group of liver specialists in the U.S. showed that from 2004 to 2013 cases of damage caused by herbal and dietary supplements increased from 7 to 20 percent of patients assessed.
- According to a recent study in the New England Journal of Medicine, each year in the U.S. 23,000 emergency room visits are due to dietary supplements, including herbal supplements.
- Use of ephedra as a weight loss aide in the U.S. in the 1990s was linked to “catastrophic events such as sudden death, heart attack, or stroke,” by the RAND Corp. (a nonprofit, nonpartisan research organization).
- Millions of people in Taiwan, China, and elsewhere in East Asia have taken the Aristolochia that caused kidney failure and urinary tract cancer in those Belgian women years ago. Although China has outlawed the production of herbs containing Aristolochia, those who used it remain at increased risk because the damage is irreversible. Aristolochia is only one of hundreds of herbs, and little is known about most of them.
- In India, where the tradition of Ayurvedic medicine goes back at least 2,500 years, use of herbal medicines has been linked to heavy metal poisoning. Surveys from Africa also document significant kidney damage, poisonings, and mortality attributable to the use of traditional herbal remedies.
These are only isolated indications of the harm caused by botanicals. Due to the lack of systematic monitoring and mandatory notification of regulatory agencies, adverse events and deaths from use of herbal supplements are likely to be greatly underestimated.
Only recently has systematic study using evidence-based methods begun to evaluate the claims made by peddlers of dietary and herbal supplements. Rigorous assessments of herbal remedies, including St. John’s Wort, Gingko Biloba, ginseng, echinacea, and others show that they have no effect on many of the diseases and medical conditions for which they are used. These include diabetes, cancer, multiple sclerosis, osteoporosis, asthma, and hepatitis. In the main, the perceived benefits from herbal and other traditional remedies are simply due to the placebo effect.
In spite of the lack of evidence, use continues to grow: In the U.S. from 1994 to 2014, the number of dietary and herbal supplements on the market increased from 4,000 to 55,000. Sales of these products represent a $32 billion industry. According to government data, more than half of adult Americans use a dietary supplement of some kind.
The market is growing globally, too—and it’s revealed itself to be profitable. In China, from 2001 to 2013, domestic sales of Chinese herbal and traditional medicines increased by 600 percent and are currently valued at $28 billion. (China exports another $3 billion worth of traditional herbs per year.)
Cultural and political motivations also appear to play an important role. Some medical traditions, such as Chinese traditional medicine and Ayurveda, go back thousands of years and are important elements of the national culture and identity. The anti-malarial drug artemisinin was discovered by Chinese scientists using modern molecular techniques, yet the Chinese government portrayed the discovery as stemming from traditional medicine. In India, Prime Minister Narendra Modi has launched a new initiative championing the practice of Ayurvedic medicine, which represents a potent symbol of traditional and national heritage underpinning his Hindu nationalist politics. India and WHO recently signed a landmark agreement to promote traditional medicine.
Thus, for powerful WHO member states like China and India, promoting traditional medicine appears to be a means of showcasing their distinctive national heritage. While traditional practices may be valued for their cultural significance, in the modern age, where people’s health is at stake, they need to have evidence to back them up. Unfortunately, rather than help the relevant communities to assess these practices, WHO is caving in to lower standards and putting people at risk.
In a commentary in EMBO Reports in April, two scientists, Arthur Grollman of Stony Brook University School of Medicine and Donald Marcus of Baylor College of Medicine criticized WHO for neglecting evidence-based methods in assessing traditional medicine. They stressed a number of crucial points that WHO glosses over in its assessment of the state of natural remedies. First, many plants produce toxins to ward off pathogens and predators, and it is a mistake to consider them safe simply because they are “natural” and have a long history of use. Second, because the adverse effects may not manifest themselves for years, the link is often not made to the causative herb—for example, Aristolochia has been used in virtually every major culture for millennia without its toxic and carcinogenic effects being recognized until the Brussels outbreak. They also point out that evidence of adverse cardiovascular events from ephedra continued to accumulate for nine years before the FDA belatedly banned this herb. Finally, very few randomized clinical trials have been done to document the claimed benefits of herbal remedies. Where these have been done, the treatment proved no better than placebo (which, incidentally, probably explains Olympian Michael Phelps’ affection for cupping). Thus, the harms from botanicals have gone largely unrecognized, whereas the ostensible benefits are largely illusory.
Other commentators echo these criticisms and, in addition, charge that WHO’s emphasis on the suitability of traditional medicine for low-resource countries implies a double standard. Why should untested medicine and unproven interventions be all right for the poor?
Grollman and Marcus stress that there is a “virtually complete lack of communication between the biomedical community and organizations representing traditional healers in countries that have a strong culture of traditional medicine.” There is also a near total lack of epidemiologic data concerning herbal toxicity in areas where traditional healing is predominant. These are the real imperatives that should be addressed by WHO.
So what’s to be done about this? WHO should acknowledge its failure to take an evidence-based approach to evaluating traditional medicines. It should become a full participant in a concerted, international effort to mitigate further harm from botanical remedies by requiring evidence-based assessments of whether they work and whether they are safe. And it should find a way to bridge the communication gap between the biomedical community and practitioners of traditional medicine.
In the meantime, we should be on the lookout for the next Aristolochia, the next ephedra, or the next bitter orange.