- Xi yang shen
- Western ginseng
For Patients & Caregivers
American ginseng has not been shown to treat or prevent cancer.
Scientists think that the medicinal properties of American ginseng come from components called ginsenosides, but most research has been done on another species, Panax ginseng. Ginsenosides both stimulate and inhibit the central nervous system in humans and stimulate the immune system in mice. Other lab studies suggest that American ginseng may have some anticancer properties.
In human studies, American ginseng was shown to lower blood sugar levels, reduce number and severity of colds, and improve memory. It may also be useful in reducing cancer-related fatigue. However, breast cancer patients should use this herb with caution because it can stimulate the growth of breast cancer cells. American ginseng also decreases the blood-thinning effects of warfarin, a commonly used anticoagulant.
- To improve athletic performance
No scientific evidence supports this use.
- To prevent and treat cancer
There are no data to back this claim. Studies suggest that American ginseng may improve cancer-related fatigue and quality of life. However, breast cancer patients should use this herb with caution because it can stimulate the growth of breast cancer cells.
- To treat diabetes
A few studies show a blood glucose-lowering effect of American ginseng.
- To stimulate the immune system
Some studies show an immunostimulant effect in animals. Human data are lacking.
- For increased strength and stamina
One trial suggests that American ginseng may improve cancer-related fatigue. Additional confirmatory studies are needed.
For Healthcare Professionals
A popular herb often confused with Asian or Panax ginseng, American ginseng has unique medicinal properties. It is frequently used in Chinese medicine to nourish “Yin” (1). American ginseng is also used in supplemental form to improve athletic performance, strength, and stamina, and to treat diabetes and cancer. The saponin glycosides, also known as ginsenosides or panaxosides, are thought responsible for the herb’s biological effects. Ginsenosides have both stimulatory and inhibitory effects on the central nervous system (4), and can alter cardiovascular tone, enhance humoral and cellular-dependent immunity, and exert anticancer effects (3) (15) (16) (28).
Current data suggest that American ginseng may improve glucose control in diabetics (2) (6) (29) and that it is safe for long-term use (25). It also demonstrated a modest effect in reducing number and severity of colds (12), and enhanced working memory in young (21) and middle-aged (27) healthy adults as well as in patients with schizophrenia (24).
In laboratory studies, the anticancer activity of American ginseng was enhanced when combined with antioxidants (14). The herb also showed synergistic effects with 5-fluorouracil against colorectal cancer cells (17), and conferred protection against oxidative stress in irradiated human lymphocytes (18).
Data from an epidemiological study indicate that American ginseng improves survival and quality of life in breast cancer patients (13). Findings from a randomized controlled trial support its benefits in improving cancer-related fatigue (23).
Ginsenosides are thought responsible for American ginseng’s activity, although the exact mechanism of action is unknown. Related species, such as Panax ginseng, have been the focus of most laboratory and clinical research. Experiments using extracts from these species indicate that ginsenosides stimulate and inhibit the central nervous system (4). The extracts also stimulate TNF alpha production by alveolar macrophages (10).
The Rg1 ginsenoside present in American ginseng is associated with improvements in humoral and cell-mediated immune response and increases in T helper cells, T lymphocytes, and NK cells in mice (5). American ginseng was also shown to lower serum glucose and may affect carbohydrate metabolism (2) (6).
Several ginsenosides demonstrated anticancer properties in vitro (3). Current data suggest that the antiproliferative effects of American ginseng are due to compound K, a metabolite of the ginsenoside Rb1, but not Rb1 as previously thought (22). In a rodent study, the herb significantly attenuated colon carcinogenesis by reducing tumor number and load, associated with suppression of proinflammatory cytokine activation (26).