How much do you care about the quality of the vegetables we eat every day? Are you worried that the vegetables may be contaminated by heavy metals or other chemicals from the water source near the farms? Do you care about the farming practices that produce your daily vegetables?
These are some of the questions that also become increasingly important to authorities that regulate TCM medicinal herbs. At the time of the start of modern medicine (AD 1852), Chinese population was ~334 million and most of TCM medicinal herbs were collected from the wild in their natural habitats. However, nowadays, with increasing demand for TCM medicinal herbs, it is impossible to meet the need solely by collecting herbs from nature, without doing harm to our environment. Therefore, more and more TCM medicinal herbs are cultivated from farms. Then what are the potential problems and possible solutions?
Similar to other farm produce, the use of herbicides and pesticides and the levels of harmful substances (e.g. heavy metals) in irrigation and in soil will inevitably affect the quality and safety of TCM medicine herbs. These are especially important since some TCM medicinal herbs have long growing cycles, which may allow cumulation of harmful substances in the herbs. One such example is ginseng, an important TCM medicinal herb which is present in various TCM formula; importantly, ginseng is usually harvested at 3-10 years after cultivation. Therefore, it is especially important to regulate the resources used in farms that cultivate ginseng. In a recent application of Globally Important Agricultural Heritage Systems (GIAHS), Korean Ginseng Agriculture System is described in details. Under Good Agricultural Practices (GAP) system, soil and water quality of each participating farm is evaluated for the presence of harmful substances and pesticides. In addition, the cultivation and harvest of ginseng are regulated by a standardized ginseng cultivation guidelines.
Why the method of harvest matters? Traditionally, roots of ginseng are considered to have the highest medicinal value. Modern research studies show that ginsenosides, a group of chemical compounds that are unique to ginseng, are the active ingredients that give the health benefits of ginseng. Interestingly, some ginsenoside compounds are only present in main root and root hair (1). Thus, it is possible that the more intact the ginseng root, the higher the medicinal content of the harvested plants.
Then, what else can affect ginsenoside content in a ginseng plant? One study on incorporation of gypsum to the soil (2) suggested that this farming practice increased soil calcium content and slightly increased soil acidity, and thus making the condition of the soil closer to the natural condition where wild ginseng is usually found. Furthermore, the study also showed that slightly increasing soil calcium content could increase the amount of ginsenoside in the plant.
An interesting point to note, in North America, some farmers have planted American ginseng (Panax quinquefolis) under natural forest canopy. These Wild-simulated / woods-grown ginseng are said to have a more ‘rugged’ appearance at the root, resembling more to the ginseng root found in the wild. Woods-grown ginseng is believed to have higher medicinal value than farm-cultivated ones and, thus, has a higher market value. However, there is no proper scientific or clinical studies on whether wild ginseng or woods-grown ginseng is more effective in helping patients to restore health.
All the above points point to a question that TCM practitioners, followers / users, and relevant regulatory bodies need to answer: Shall we standardize the farming practices of ginseng cultivation, both locally or internationally? Shall we specify the amount of ginsenosides present in a ginseng plant / extract, in order for it to be considered as a ‘medicine’? In TCM practice, ginseng is prescribed as part of formulae to restore the health of those people who are generally in ill health, suffer huge loss of blood, or with constant fatigue. On the other hand, ginseng is also among the 10 most commonly-used non-vitamin supplements in U.S. The popularity of ginseng lies on the assumption that the plant / extract that the consumers bought contains appropriate amount of active ingredients to produce its health benefits. But the health benefits of ginseng can be compromised by inappropriate farming practices.
Or maybe the future of TCM medicine should focus on purifying the active ingredients from their origins, and create drugs resembling the ones used in modern medicine?
- Ok-Ju Kang and Ji-Sang Kim. Prev Nutr Food Sci. 2016; 21(4): 389–392.
- Jinwook Lee and Kenneth W. Mudge. Horticulture, Environment, and Biotechnology. 2013; 54(3): 228-235