| American Ginseng (Panax Quinquefolius) | | | | placebo-controlled studies by the same |
| Herb Description: | | | | investigators, a single dose of American ginseng was |
| The American ginseng plant, Panax quinquefolius, is | | | | found to reduce post-prandial glycemia by about |
| similar in appearance and is in the same botanic genus | | | | 10-20%. Effects were not found to be dose |
| as Asian ginseng (panax ginseng). First described in | | | | dependent. In healthy subjects, 1-3 g doses reduced |
| the early 18th century in Eastern Canada, P. | | | | glycemia when given at least 40 minutes before a |
| quinquefolius was primarily harvested for export to | | | | glucose load. In type-II diabetics, 3-9 g doses were |
| China. American ginseng is also referred to as North | | | | tested and found to reduce glycemia when given |
| American, Canadian, or Wisconsin ginseng, referring | | | | with, or up to 2 hours prior to, a glucose load. |
| to primary areas of harvest or cultivation, although it | | | | Adverse Effects: |
| is now grown in many areas of the world. The root is | | | | No significant adverse effects have been reported in |
| used medicinally. | | | | the few clinical trials, and there are no case reports |
| Uses and Benefits | | | | of clinical toxicities. Due to similar chemical |
| Ginsengs are marketed in the U.S. to boost energy, | | | | constituents, American ginseng has the potential to |
| relieve stress, improve concentration, and enhance | | | | cause any of the side effects possible with Asian |
| physical or cognitive performance. Most ginsengs are | | | | ginseng, which appear to be uncommon and |
| believed to act as general restoratives, tonics, or | | | | idiosyncratic. |
| adaptogens, which have nonspecific strengthening | | | | Side Effects and Interactions: No drug interactions |
| properties to restore the body's balance, enhance | | | | are recognized. |
| stamina, and increase resistance to stress and | | | | Cautions: |
| disease. | | | | One American ginseng product has been shown to |
| In traditional Chinese medicine (TCM), Asian and | | | | mildly blunt the hyperglycemic effect of food; this |
| American ginsengs are used to restore vital energy in | | | | may theoretically be detrimental in a tightly controlled |
| the body. However, American ginseng is considered | | | | or labile diabetic. Unlike Asian ginseng products, |
| to have more cooling or calming qualities, as opposed | | | | adulteration or contamination of American ginseng has |
| to Asian ginseng's more heating or stimulating | | | | not yet been reported. Safety has not been |
| properties. According to TCM theory, American | | | | established during pregnancy or breast feeding. |
| ginseng is used to calm the ailing respiratory or | | | | Preparations & Doses: |
| digestive systems and as therapy for diabetes or | | | | American ginseng is available in multiple forms, from |
| "thirsty" syndromes, and may be preferred in warmer | | | | whole root products to a variety of more |
| climates. | | | | concentrated formulations and extracts in capsules, |
| Native Americans traditionally employed American | | | | tablets, liquids, teas, and foods. The crude root is |
| ginseng to help with childbirth and fertility and to | | | | usually taken in doses of 1-2 g/day, but up to 9 g or |
| strengthen mental powers, and for a variety of | | | | more is used in traditional Chinese medicine. Many |
| ailments such as respiratory disorders, headaches, | | | | formulations contain concentrated extracts or |
| and fevers. | | | | preparations standardized to ginsenosides, usually as |
| Clinical Trials: | | | | 100-200 mg of extract per dose. |
| There are few controlled clinical trials using American | | | | Summary Evaluation: |
| ginseng products. In one randomized, double-blind, | | | | American ginseng, like Asian and Siberian ginseng, is |
| placebo-controlled crossover study of eight athletic | | | | traditionally used as a tonic or adaptogen to enhance |
| volunteers, a noncommercial American ginseng | | | | health and combat stress or disease. Few clinical trials |
| extract in a daily dose of 8 - 16 mg/kg for 7 days | | | | have been conducted. In one well-designed study, |
| failed to enhance physical performance as measured | | | | American ginseng did not enhance physical |
| by a cycle ergometer. There were no significant | | | | performance. In another series of studies, single |
| differences compared to placebo in any of the | | | | doses of one product mildly attenuated post-prandial |
| outcome measures, which included oxygen uptake, | | | | glycemia; whether this effect is reproducible and |
| heart rate, time to exhaustion, lactate and glucose | | | | beneficial for diabetics awaits chronic dosing trials. |
| concentrations, and rating of perceived exertion. | | | | There are no well-documented adverse effects of |
| In a series of randomized, single-blind, | | | | American ginseng. |