A year or so ago, I was translating a class for a Shang Han Lun doctor named Huang Huang, and we received an interesting question from one of the practitioners in the audience. This particular practitioner had learned at their Shang Han Lun class in school that the medicinal used as Ren Shen was actually Dang Shen in ancient times. This raises an interesting question and a debate that is worth investigating.
The crux of the argument for Dang Shen as the ancient source of Ren Shen is based on a geographical statement of quality from Tao Hong-Jing’s 5th century annotated edition of the Shen Nong Ben Cao Jing (Divine Farmer’s Classic of Materia Medica). Tao stated that the Ren Shen from the “shang dang” region in modern-day Shanxi province was of high-quality. At present, there is no ginseng growing in the shang dang region, but the herb Dang Shen is native to the shang dang region of Shanxi so some people believe that the ancient item used was Dang Shen.
If we look a bit closer, however, there are significant reasons to doubt this theory. Dang Shen, a plant from the same family as Jie Geng, first emerged in the Chinese literature in the 18th century, right around the same time as American ginseng entered the Chinese materia medica. Both items did not have recorded use prior to the 18th century, and the two emerged as ginseng substitutes at a time when wild ginseng populations had already begun to decline dramatically. It seems rather unlikely that the Chinese people once knew how to identify Dang Shen and used it as one of their most important medicinals, then forgot about it and erroneously used Panax ginseng in its place for 1600 years before finally re-discovering and recording Dang Shen in 1757 A.D.
The ancient nomenclature of ginseng also strongly suggests that Panax ginseng is the true Ren Shen product. The name Ren Shen itself means “human root,” which is believed to be a reference to the fact that the root grows with a human-like shape. By contrast, Dang Shen grows a single large, deep, unbranched tap root that has no particular resemblance to the human form. Furthermore, another ancient name of ginseng is “spirit herb” (shen cao), and one of the key clinical differences between ginseng and codonopsis is that only ginseng supplements heart qi and quiets the spirit.
A thorough examination of the literature also draws more doubt to the ancient Ren Shen = codonopsis theory. According to research from my teacher Zhao Zhongzhen, prior to the Song dynasty, ginseng had a much wider growing range than it has at present, including Hebei and Shanxi. Furthermore, ancient illustrated materia medica texts document that a plant in the ginseng family (Araliaceae) grew in Shanxi province in days gone by. According to Dr. Zhao as well as the published works of Dr. Chang Hsien-Cheh of China Medical University, the ancient statements that high-quality Ren Shen came from the shang dang region resulted in high market demand and overharvesting that led to exhaustion of the wild populations of ginseng in the region. By the Qing dynasty, the recognized “dao di” area for superior, authentic ginseng had already changed to Northeastern China (modern-day Jilin, Liaoning, and Heilongjiang provinces) and the ginseng supply of other regions was likely already largely exhausted. The Qing emperors were Manchurians, and the Northeastern region was their ancestral homeland; common people thus couldn’t harvest products from the Manchurian forests under pain of death and Manchuria became the only region where wild ginseng survived extinction.
As wild ginseng began to become increasingly rare, ginseng cultivation began and substitutes began to emerge. In the quest for ginseng alternatives, Xi Yang Shen and Dang Shen emerged; Xi Yang Shen came from the Americas and Dang Shen came from ginseng’s original homeland in shang dang (Shanxi province). Dang Shen has now emerged as a major ginseng alternative, though it lacks ginseng’s actions of greatly supplementing original qi and supplementing heart qi to quiet the spirit. The use of ginseng alone in prescriptions such as Du Shen Tang to stem desertion thus further lends support to the idea that the original medicine used was ginseng, not codonopsis.
Personally, even beyond these clinical differences and evidence from the extant historical literature, I think it is simply a bit of a stretch to believe that hundreds of thousands of Chinese, Japanese, and Korean doctors have had it all wrong for centuries. The idea that millions of people have been revering the wrong herb for centuries seems unlikely, and anyone who has actually eaten wild ginseng in comparison with wild codonopsis will tend to have the direct experience that ginseng is more profound. Ginseng extends beyond medicine into culture and art; it is deeply prized on many levels and it just seems hard to believe that all these people are somehow mistaken and it was originally supposed to be Dang Shen all along.