Focus on Alternative and Complementary Therapies
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Focus Alternat Complement Ther©2005 Pharmaceutical Press
Focus Altern Complement Ther 2005; 10: 94–7
Chinese herbal medicine (CHM) is fast becoming popular in the West. This development has to be seen in context with a more general trend towards CM. In the USA, for instance, the usage of complementary therapies by the general population has increased from 33% in 1990 to 42% in 1997.1 The US data follow a trend that can be noted in most Western countries.2 Indisputably, CHM is amongst those complementary treatments growing fastest. Due to this increasing demand, CHM has now become one of the most important areas for Chinese exports into the West. Each year about 10 000 tons of medicinal herbs are exported from China.3 The commercial and medical potential for integrating CHM into Western health care is immense.
In this focus article, I address some of the issues that are likely to become crucial on CHM’s way to success in the West.
Many Western healthcare professionals worry about the quality of some of the CHMs reaching their markets. CHMs have repeatedly been associated with inconsistent quality. The foremost and obvious issue here is to avoid risk to consumers. A recent report3 mentioned that ‘only one of 17 samples of the drug Lui Shen Wan was of good quality’ when tested analytically. We have recently conducted two systematic reviews of the literature on the contamination and adulteration of CHM. Twenty-two publications were identified associating CHMs with contamination with heavy metals.4 The most frequently found contaminant was lead. It was also noted that, in some instances, heavy metals were deliberately added to CHMs for alleged medicinal purposes according to the concepts of traditional Chinese medicine. Apart from heavy metals, a range of other contaminants need to be considered (Table 1). In the second review, we located 18 case reports, two case series and four analytical investigations that associated CHM with adulteration by conventional prescription drugs.5 Further instances of adulteration have emerged since.6 The list of adulterants now includes drugs with serious adverse effects and considerable potential for harm to patients/consumers (Table 2). National regulatory agencies have therefore issued repeated warnings regarding the use of CHM.6
Table 1. ‘Contaminants’a found in CHM
| Animal productsb |
| Heavy metals |
| Human body parts (e.g. placenta) |
| Microorganisms |
| Pesticides/herbicides |
| Toxins from microorganisms (e.g. aflatoxin) |
| Unwanted herbal ingredients (e.g. Aristolochia spp.) |
aContaminants is in inverted commas because some of the ingredients are deliberately put into CHMs because of their alleged health effects.
bMuch opposition exists in the West against using animal material in CHMs even if they pose no safety risk.
Table 2. Adulterants found in CHM
| Aminopyrine |
| Clobetasol propionate |
| Dexamethasone |
| Diazepam |
| Diclofenac |
| Fenfluramine |
| Fluocortolone |
| Hydrochlorothiazide |
| Indometacin |
| Mefenamic acid |
| Nitrosofenfluramine |
| Phenacetin |
| Phenylbutazone |
| Prednisolone |
It is of course not possible, based on such data, to determine how frequently problems with contamination or adulteration of CHMs arise. Hopefully these are rare, isolated cases that are not representative of CHM as a whole. However, even isolated cases must be taken seriously – not least because they do give a bad name to CHM that it may not deserve.
It is thus mandatory that the existing quality control procedures of CHMs are tightened. If CHM should be fully accepted in the West, its products must comply with regulations in these countries. This means that growing, harvesting, storing, processing and manufacturing of CHMs must adhere to the accepted standards of Western good practice.
The lack of toxicity of (uncontaminated, unadulterated) herbal mixtures or extracts cannot be assumed but must be demonstrated. In many instances this could prove to be a substantial task, not least because in traditional Chinese medicines mixtures of several medicinal herbs are frequently used. To make things even more complex, animal and even human body parts (e.g. human placenta, deer antler or donkey skin) are sometimes also included.6 This renders toxicity studies more complex than those of single herbal ingredients. The often-voiced argument that treatments that have been used for hundreds or thousands of years must be safe, is scientifically not convincing (Table 3).7 Traditional use might render safety problems less likely but it certainly does not exclude them totally. A further safety concern is labelling; many CHMs for sale in the UK are labelled in Chinese only.6 It is obvious that this defeats the purpose of providing adequate information for the customer.
Table 3. Reasons why traditional use is not a reliable indicator for safety
| Adverse effects could be long term and thus not noticeable in clinical practice |
| Adverse effects could be too rare for detection but still important clinically |
| Traditional use might refer to a different dose, extraction method, route of administration, etc. |
| Herbal remedy could interact with drugs that have only recently become available |
| Herbal medicines are used for different conditions than traditionally |
| Westerners might react differently to CHM than Chinese people |
In Western countries herbal remedies are often marketed as ‘dietary supplements’ or even sold on the grey market outside any legal category. As such they generally do not require proof of efficacy. Nevertheless, the long-term success of CHM in the West in terms of acceptance by consumers and healthcare professionals will depend on how convincingly CHM can demonstrate reliably and reproducibly that it cures a disease or alleviates symptoms. Establishing efficacy will have to follow the accepted standards in the West. In other words, the rules of EBM unquestionably also apply to CHM.
Some proponents of CHM are keen to point out that CHM cannot be tested for efficacy in RCTs. They claim that, because CHM mixtures are individualised to each patient according to the rules of traditional Chinese medicine, RCTs are not feasible. This is not true and is probably based on misunderstandings; RCTs of CHM may well be more complex than those of single synthetic drugs, but they are clearly possible. Nothing can demonstrate this point more convincingly than the undeniable fact that several such RCTs have been published (and have generated encouraging results). Two examples of recent trials may suffice for the purpose of this article.
Bent et al8 conducted a trial with 237 elderly individuals who suffered from lack of energy and decreased memory or sexual function. They were randomised into two groups. The experimental group took a CHM formula (Longevity Treasure, Enwei Pharmaceuticals, China) for 30 days, while the control group were given indistinguishable placebos. The results showed that the CHM group generated a larger increase in cognitive function than did the placebo group.
Xue et al9 treated 55 patients suffering from seasonal allergic rhinitis either with a CHM mixture of 18 different herbs or with placebo. The primary outcome measure was a score for the severity of the rhinitis symptoms. The treatment period lasted 8 weeks. At its end, the symptoms had decreased significantly more in the CHM group compared to the control group.
In addition to these recent studies, there are many more clinical trials in the older medical literature. In a series of systematic reviews of ‘alternative’ treatments for a range of conditions, we found numerous clinical studies of CHM.10 Key data from these investigations are summarised in Table 4.
Table 4. Examples of clinical trials of CHM
| Indication | Nature or name of CHM | Resulta |
|---|---|---|
| AIDS/HIV infection | Complex herbal mixture | Negative |
| Alzheimer’s disease | Choto-sanb | Positive |
| Asthma | Complex herbal Mixture | Tentatively positive |
| Atopic eczema | Complex herbal Mixture | Inconclusive |
| Cancer prevention | Green tea | Tentatively positive |
| Cancer prevention | Ginseng | Positive |
| Cancer treatment | Destagnation | Tentatively positive |
| Cancer treatment | Sho-saiko-tob | Tentatively positive |
| Congestive heart failure | Sunitang | Tentatively positive |
| Drug dependence | Complex herbal mixture | Tentatively positive |
| Drug dependence | Kudzu | Negative |
| Erectile dysfunction | Mustong | Positive |
| Headache | Tiger balm | Tentatively positive |
| Hepatitis | CH100 | Tentatively positive |
| Hepatitis | Jiedu yanggan gao | Tentatively positive |
| Hepatitis | Liquorice | Positive |
| Hepatitis | Sho-saiko-to | Tentatively positive |
| Hypercholesterolaemia | Red yeast rice | Positive |
| Irritable bowel syndrome | Complex herbal mixture | Positive |
| Menopause | Ginseng | Positive |
| Rheumatoid arthritis | Thunder god vine | Positive |
| Respiratory tract infection | Complex herbal mixture | Tentatively positive |
Data extracted from reference 10.
aNegative = not suggesting efficacy; positive = suggesting efficacy.
bKampo medicine (Japanese version of CHM).
A Medline search of human studies of CHM yields fascinating results: during the last two decades the number of Medline-listed articles on this subject has increased exponentially (Figure 1). The fact that such encouraging results are now appearing in Western medical journals is significant. It suggests that clinical trials of CHMs are now being conducted to a standard that is acceptable to the scientific community in the West. In the past, there was considerable doubt about the methodological qualities of studies originating from China.11,12 More and more such studies are presently being initiated in leading research centres worldwide. Their results are awaited with great interest and will importantly impact on the future acceptance of CHM by the medical profession in the West.
Figure 1. Number of citations related to human studies of CHM in Medline. Data based on Medline search conducted 9 March 2004 via Pubmed.
Health care has become an immensely expensive business and sizeable proportions of our national wealth are being spent on it. Budgets for medicines are tight everywhere in the world. Any drug that wants to succeed in these competitive markets would therefore need to convincingly demonstrate cost-effectiveness.
To date, no rigorous cost-evaluations of CHM have become available. But, generally speaking, the cost for most CHMs are not high; often they are substantially lower than costs for synthetic drugs used for the same condition. If CHMs could achieve a similar benefit at lower costs than conventional drugs, their acceptance in the West would certainly increase.
China has huge resources for herbal medicines and relatively little is known about them in the West. There can be no doubt that there is considerable therapeutic potential in CHM. Similarly, there can be little doubt about the need for more information on all sides. The market for CHM in the West is very likely to expand rapidly in the foreseeable future. If this expansion is to be a long-term success, it is crucial to demonstrate product quality, safety, efficacy and cost competitiveness according to standards generally accepted in the West.
