Ginseng is one of the most widely used and highly researched herbal remedies in the world. Drugs.com says that as of 2011, more than 6 million people take ginseng regularly in the United States. The term "ginseng" can refer to either American ginseng or Asian ginseng. Both varieties are used to promote well-being and improve physical and mental performance under stress. Siberian ginseng, a third type, is a distant relative, with different constituents and properties. Animal and human studies have shown that ginseng may help prevent or reduce the severity of certain illnesses. Consult your doctor before taking ginseng.
Features
American ginseng -- botanically known as Panax quinquefolia -- has been harvested to the brink of extinction in the United States and is now cultivated primarily in British Columbia and Wisconsin, while Asian ginseng -- or Panax ginseng -- is grown in Korea and China. Most ginseng remedies are made from the rhizome, or underground stem, of the plant. The rhizome's general resemblance to a human shape caused herbalists to believe that the herb could treat human ills. Asian ginseng has been used in traditional Chinese medicine to treat many conditions, including diabetes, impotence, breathing difficulties and insomnia. American ginseng was employed by Native Americans as a stimulant and to treat headaches, fever, digestive problems and infertility. Ginseng is available in food flavorings, fresh and dried roots, extracts, capsules, sodas and teas.
Constituents and Effects
Many of ginseng's beneficial effects are due to its content of ginsenosides, a group of glycosides metabolized by bacteria in the digestive tract. Polysaccharides and xanthines are also present in ginseng, as are assorted volatile oils and flavonoids. In addition, ginseng contains B-complex vitamins and assorted minerals. Ginseng is believed to have adaptogenic properties, meaning it increases the body's resistance to stress factors. According to a 2003 article by Dr. David Kiefer and Traci Pantuso in "American Family Physician," ginseng acts on the immune system by producing higher activity levels of natural killer cells, increasing total lymphocyte count and raising levels of T-helper cells. Studies have shown that taking ginseng can result in a lower incidence of influenza and colds.
Research
There is some clinical evidence that herbal ginseng products can help enhance the immune system and reduce the frequency, severity and duration of cold and flu symptoms. In a placebo-controlled trial published in 2004 in "Journal of the American Geriatrics Society," researchers found that subjects who took a ginseng extract had a lower incidence of acute respiratory illness than the control group. In a double-blind, placebo-controlled study published in 2005 in "Canadian Medical Association Journal," researchers found that a ginseng product reduced the duration of colds, as well as the symptoms. They speculated that ginseng increased the activity of T-helper and natural killer cells, while decreasing levels of immunoglobulin A.
Dosages and Precautions
Ginseng can be taken in the form of extracts standardized to contain 4 to 5 percent ginsenosides at doses of 100 to 200 mg one to three times a day. Consult your doctor before using ginseng, especially if you have high blood pressure or diabetes or are taking blood-thinning medications. If you have bipolar disorder, are pregnant or breastfeeding or have a history of breast cancer, don't use ginseng. Ginseng contains caffeine and theophylline, which may cause nervousness and sleeplessness. Other adverse reactions include diarrhea and vomiting. Drugs.com says that some commercial ginseng products may be contaminated with pesticides. Purchase ginseng only at reputable health food stores.
References
- Drugs.com: Ginseng
- University of Maryland Medical Center; American Ginseng; March 2010
- "Journal of the American Geriatrics Society"; A Placebo-Controlled Trial of a Proprietary Extract of North American Ginseng To Prevent Acute Respiratory Illness In Institutionalized Older Adults; Janet E. Mcelhaney et al.; 2004
- "Canadian Medical Association Journal"; Efficacy of an Extract of North American Ginseng Containing Poly-Furonosyl-Pyranosyl-Saccharides For Preventing Upper Respiratory Tract Infections: A Randomized Controlled Trial; Gerald N. Predy et al.; October 2005
- "American Family Physician"; Panax Ginseng; David Kiefer, M.D., and Traci Pantuso, B.S.; October 2003
