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By David Schiedermayer, MD
Human beings have always searched for a panacea, herb, or medication that is complex enough to provide healing for all sorts of disease. Aspirin has been a startlingly powerful agent in Western allopathic medicine. In Asian medicine, Panax ginseng has been the panacea of choice for thousands of years. Panax ginseng has been used as a tonic, stress reliever (adaptogen), aphrodisiac, appetite stimulant, immunostimulant, cancer treatment, oral hypoglycemic agent, and life-prolonging agent. Such was its alleged power that Chinese men who were dying and had a family member traveling from a distance used ginseng so they might live a few more days. Ginseng is now the top-selling herbal product in the United States, with $78 million in annual sales, compared to the $67.6 million consumers spend on garlic, the $66 million for ginkgo biloba, $14 million for echinacea, and $13.5 million for St. John's wort.1 Worldwide sales of ginseng are worth $3.75 billion annually.
Can more than a billion people be wrong, century after century, about the benefits of a drug they are taking? Ginseng raises that fascinating clinical question.
Natural History and Cultural Tradition
The ginseng plant is one of the most ancient of modern living plants. The fossil record shows that ginseng grew on the supercontinent known as Pangaea during the lower Jurassic period. Ginseng is a tap-rooted perennial with a rhizomal underground stem from which a single annual stalk arises. Plants more than five years old (with 5 scars on the rhizome) contain the highest yields of the active compounds known as ginsenosides. "White" ginseng is simply the dried root, and "red" ginseng has been steamed for several hours, then sun- or fire-dried.
"Seng" is a word used by Chinese herbalists for fleshy rootstocks used for tonics. More than 60 "seng" plants exist. Ginseng translates into "the essence of earth in the form of a human," and ginseng roots sometimes resemble the human form. For centuries, Panax ginseng grew wild in northeast China, Korea, and southeastern Siberia, but the wild plant is now extremely rare, harvested to near extinction. Fewer than five pounds are dug each year. A single root has been sold in Tokyo for $20,000.2
The taxonomy of ginseng preparations and plants are listed in the Table.
Most Asian ginseng is now grown under cultivation in northeast China, and much of the ginseng sold in Asia is cultivated American ginseng (Panax quinquefolius), which is grown in Wisconsin and Canada. The Chinese use far less per capita than wealthier Asians, with the average South Korean consuming 10 times more and someone from Hong Kong using 40 times more than a Chinese person.3
Active ingredients include at least 18 identified saponins or "ginsenosides" (GS), which are dammarene-type triterpene oligoglycosides as well as complex pectic polysaccharides and acetylenic fatty-acid glycosides.4 Studies show a complex profile of activity that is sometimes difficult to reconcile with the existing chemical structures. In vitro studies showed GS compounds scavenge hydroxyl radicals and are functional ligands of the glucocorticoid receptor.5,6 Some calcium channel-blocker activity has been found.7 The GS saikosaponin suppressed antibody-induced glomerulopathy in rat kidneys.8 Standardized ginseng preparation (G115) is a pulmonary vasodilator that has been shown to protect against free-radical injury in rabbit lungs.9 Ginseng also has a mild estrogen-like effect.10
Theoretical Mechanism of Action
In Chinese medicine, ginseng is used to restore the body's balance and normalize body functions. According to theory, herbs work in four ways to regulate health: as tonics, purgers, consolidators, or dispersers.
Tonics invigorate the body and help make up for natural deficiencies. They build up a patient's "qi" or vital life force.
Purging herbs rid the body of harmful fluid or phlegm, consolidating herbs are astringents that tighten or pull areas of weakness, and dispersing herbs decrease stagnation.
Ginseng is a tonic herb, or "adaptogen" that increases the body's resistance to disease, increases stamina, and enhances recovery.11 The Chinese consider American ginseng to be cooler, with more "yin," and, therefore, better-suited to women than men and best used to reduce the heat of respiratory and digestive tracts. Asian ginseng is considered warmer with more "yang," helpful for the blood and circulatory system, particularly in men over age 50. Panax ginseng and Panax quinquefolius differ in concentrations of ginsenosides, which may explain the different effects on the body described in Chinese medicine.2
Most studies involve Panax ginseng and use a standardized extract of 4% or 7% ginsenosides. A study of 31 healthy men showed no improvement on treadmill testing when taking ginseng. Parameters measured included heart rates, lactate levels, oxygen levels, and perceived exertion. Several other studies have confirmed the lack of ergogenic effects of ginseng ingestion.12 In terms of immunomodulation and hormonal studies, 20 healthy young Thai men divided into treated and untreated groups showed no differences in total and differential leukocyte counts, including helper cell subsets.13 Male patients with oligospermia treated with ginseng extract had an increase in spermatozoa number and motility and an increase in plasma testosterone, FSH, and LH, but a decrease in prolactin.14 Thirty-six type-II diabetic patients demonstrated improvement in mood and in fasting blood glucose and glycosylated hemoglobin on ginseng in a double-blind, placebo-controlled study (200 mg dose).15
Studies on mental performance and quality of life may show some ginseng benefit. A Swedish study of 390 people and a Mexican study of 625 people16 showed that ginseng, in combination with vitamins and minerals, resulted in improvements in memory, fatigue level, and reported well-being. The Mexican study was randomized and double-blinded (control patients received vitamins and minerals alone) but relied on an 11-item quality-of-life questionnaire. It is interesting to note that, based on its analysis of the overall ginseng studies, the German health authorities permit Asian ginseng products to be labeled as a tonic for treatment of fatigue, decreased work capacity, and convalescence.
Ginseng is marketed in the form of slices, tonics, powders, tablets, teas, extracts, confections, and fruit and mineral drinks. Other ginseng products include toothpaste, cosmetics, soaps, candies, and even baby food in the Orient. Most Asian users and purists ingest ginseng by chewing dried root, eating sliced root in salads, or boiling roots for pure ginseng tea.17 Most American consumers prefer the capsule or gel form, and reputable tablet brands include Nature's Way, Gaia Herbs, Herb Pharm, Bioforce, Botanical Pharmaceuticals, and Eclectic Institute.
The recommended dose of a typical product containing 4% ginsenosides is two 100 mg capsules daily, in single or divided doses, with or without food. Powdered or cut ginseng dosage is variable in strength, but the dosage is generally between one-half and two teaspoonfuls. The dose of tinctures or concentrated extract varies between 10-30 drops, but the lack of a standardized dosing makes monitoring difficult. Tinctures are often more expensive but last for years. They taste bitter, and most contain alcohol. Powder capsules cost less, are tasteless, but last for only one year. Teas are warm and soothing and may be sipped throughout the day but are time-consuming to prepare and have a limited shelf-life.18
Several reports of toxicity have been traced to mislabeled or adulterated products. People should avoid products that mix multiple herbs in formulas claiming to cure almost everything. Germanium is present in many ginseng preparations and should be avoided. A 63-year-old man with glomerulonephritis became refractory to diuretics after taking Uncle Hsu's Korean ginseng, which contained a germanium compound. Germanium is known to cause nephrotoxicity in the nephron segment where loop diuretics act.19
Prolonged used of ginseng may be associated with increased blood pressure, insomnia, and uterine bleeding and sore breasts in women. The American Association of Poison Control Centers has one report of a ginseng-related death, a 71-year-old-woman who drank undiluted ginseng extract for two weeks, developed hepatitis, and died from liver failure. People should avoid ginseng if they have uncontrolled hypertension. Other reported adverse side effects include insomnia, palpitations, and diarrhea, especially in persons who use large doses for prolonged periods.18
Ginseng should not be used during pregnancy because of possible hormonal effects on the fetus, and it should not be used by children because of its stimulant effects. While most of the adverse side effects are reported with Panax ginseng, all ginseng products contain ginsenosides and the same side effects are possible with American ginseng. Some authors advocate the use of Siberian ginseng as safer, but, while eleutherosides are somewhat different than ginsenosides, they are similar chemically (they are saponin glycosides) and pharmacologically.20
Ginseng was associated with an elevated serum digoxin level in one case report.21 An interaction with warfarin may also exist.
Ginseng in its various forms is a relatively safe herbal remedy except when used in high doses for prolonged periods. Ginseng is not efficacious in increasing exercise tolerance or athletic performance. Doses of up to 200 mg of Asian ginseng (Panax ginseng) may improve constitutional symptoms or increase the sense of well-being, but whether this ancient herb can be endorsed as a modern panacea remains to be seen.