SEOUL, KOREA. The life-extending properties of ginseng were first described around 500 AD in a Chinese medical textbook by Shennong. Since then animal experiments have shown that ginseng's beneficial effects may be connected with its ability to prevent cancer. Now researchers at the Korea Cancer Center Hospital report that ginseng is also an effective cancer prevention agent in humans. Their study involved 4634 citizens over 40 years of age of the Kangwha region, one of the major ginseng-production areas in Korea. Each study participant was interviewed to determine demographic characteristics, occupation, smoking and drinking habits, health status and history, etc. They were also asked about their ginseng consumption - when they first started taking it, how often they consumed it, what type of ginseng they took, and for how many years they had done so. Three types of ginseng were considered; fresh ginseng which is less than four years old and consumed as is, white ginseng which is four to six years old, peeled and dried to reduce water content to 12 per cent or less, and red ginseng which is at least six years old, steamed and dried before use. The frequency of ginseng intake was divided into four categories - no intake, one to three times per year, four to eleven times per year, and more than once a month. Study participants were followed from August 1987 to December 1992. During this period 137 participants developed cancer and 79 died from it. Ginseng consumers were found to have a 60 per cent lower risk (RR=0.40) of cancer. The protective effect of fresh ginseng extract was highest at 69 per cent with the protective effect of other types being apparent but not statistically significant. The protective effect increased with frequency of consumption. The risk decrease among ginseng consumers was 67 per cent for stomach cancer and 70 per cent for lung cancer. The researchers conclude that Panax ginseng C.A. Meyer (Korean ginseng) has a non-organ specific preventive effect against cancer.
Yun, Taik-Koo and Choi, Soo-Yong. Non-organ specific cancer prevention of ginseng: a prospective study in Korea. International Journal of Epidemiology, Vol. 27, June 1998, pp. 359-64