July 19, 2000 -- Ginseng is in the spotlight again as researchers look into how well the herb can actually help fight cancer. Though some early research has shown some benefit, at least one complementary medicine expert feels that the future of this and many other hopeful herbs is not too bright.
A group of researchers say a number of animal and human studies from 20 years ago to the present show Panax ginseng may reduce the risk of several types of cancer. Their report appears in the July issue of Cancer Causes and Control -- a medical journal published in the Netherlands.
Panax ginseng is one of the most medically important varieties of ginseng in the Orient and has been used for thousands of years as a natural tonic for restoration of strength and a cure-all, or panacea (hence the name Panax), according to the researchers. Ginseng has grown very popular in this country, with sales increasing more than 20% each year, according to the American Cancer Society (ACS).
The components in Panax ginseng -- both red and white versions that the Korean researchers say fight cancer growth -- are a group of 34 constituents collectively called ginsenosides. In one 1980 study in Korea, red ginseng extract inhibited the formation of lung tumors in rats. In another study in 1983 using mice, a 75% reduction in liver cancer was reported. Other studies on mice and rats have shown reductions in cancer of the mammary glands, cervix, ovaries, kidney, stomach, and skin.
The researchers do issue one caveat about the cancer-fighting properties of ginseng, however. "While Panax ginseng has shown cancer-preventive effects," write researcher Hai Rim Shin and colleagues, "the evidence is not conclusive as to its cancer-preventive activity in humans." Shin believes further research is needed, and based on the positive results so far, is warranted. Shin failed to respond to a request for an interview by WebMD.
There have been only a couple of studies of ginseng use on humans. One study conducted by researcher Taik Koo Yun -- who also co-authored this latest study -- found that among more than 4,600 people over the age of 40, ginseng users were approximately 70% less likely to develop cancer compared to those who did not take the herb. They also found that the more frequently ginseng was consumed, the lower the risk of getting cancer was.
One skeptic is Ernst E. Cassileth, MD, from the department of complementary medicine at the University of Exeter in the U.K. He studied a variety of herbal cancer cures, including shark cartilage, mistletoe, thymus therapy, essiac, hydrazine sulphate, 714-X, dietary regimens, green tea and Panax ginseng, in a study published in the European Journal of Cancer in 1999. His conclusion: "None of these treatments offer reasonable hope for a cure," he tells WebMD.
"It's premature to make a prediction of a supplement preventing or inhibiting cancer based on a 52-day study on mice," says Ray Sahelian, MD, who has reviewed some of the Korean ginseng research and has authored books on other dietary supplements. "There are so many complicating factors involved in cancer formation that even if a supplement helps in one particular area of the immune system, it may have detrimental effects on another aspect."
The ACS has offered no official position on ginseng as a cancer treatment or preventive agent. The ACS will only say that although proponents of many herbal remedies claim to have anticancer effects, only a few have gained substantial popularity as alternative cancer therapies.
The ACS says it does recognize that ginseng has been used for centuries and there are claims that it works marvels. "But it has not yet been adequately tested in a scientific way," the ACS statement says. "Those studies that were conducted produced contradictory results. Further, studies of 54 ginseng products found that 25% contained no ginseng at all, and 60% contained only trace amounts."