in volunteers on cycle ergome­ters Four trials found a significant decrease in heart rate and an increase in maximal oxygen uptake, whereas the other four trials found no improvement. Evaluation of these studies does not suggest that ginseng significantly improves physical per­formance.

Cognitive Functioning-In two separate RCTs, the G115 preparation increased arithmetic calculation ability (without affect­ing other cognitive skills),16 while a different ginseng product en­hanced abstract thinking and auditory reaction times (without affecting memory or concentration)Y The combination G115 product improved cognitive functioning in middle-aged patients with mild memory impairments, but failed to improve cognition in geriatric patients. A combination ginseng/ginkgo preparation had equivocal effects on memory (beneficial effects after the lIlorning dose, but detrimental effects after the aft

Asian, Chinese, Korean, or "true" ginseng are all common names for Panax ginseng, one of the world's oldest known herbal medicines. The word Panax, of Greek derivation, means "all-cure" and gives rise to the word panacea. In Chinese, "ginseng" (schinseng) refers to the human-shaped figure of the root, which is believed to suggest powerful properties. White ginseng refers to the unprocessed dried root, while red ginseng refers to the steamed root, which is red or caramel colored.

Uses and Benefits:

Ginseng has been used for thousands of years in Asian countries to boost energy, relieve stress, improve concentration, and enhance physical and cognitive performance. It is claimed to be a general restorative, tonic, or adaptogen, which restores the body's balance, enhances stamina, and increases resistance to stress and disease. Among many other claims, ginseng is also recommended as an aphrodisiac, for cardiovascular diseases, to prevent or treat cancers, and to prolong life. In traditional Chinese medicine, ginseng is used to restore the vital life force (qi or chi) in the body. Asian ginseng is considered more stimulating or heating (yang), while American ginseng is considered more calming or cooling (yin).

Pharmacology:

The triterpene saponins, commonly referred to as ginsenosides, are considered to be the main pharmacologic constituents of P. ginseng. At least 30 of these steroidal compounds have been described, based on their sugar side chains. The most abundant or important ginsenosides are Rg-1, Rg-2, Rb-1, Rb-2, Rc, Rd, and Rf. Like lipid-soluble steroid hormones,ginsenosides may insert into cell membranes and interact with membrane channels and proteins, or transverse the membrane to initiate genomic effects. In addition, polysaccharides, polyacetylenes, and other non-saponin constituents of P. ginseng have pharmacologic activity.

Hundreds of in vitro and animal studies, mostly from the Asian and Russian literature, have investigated the biochemical and pharmacologic activities of P. ginseng, and numerous properties have been described. For example, pharmacologic effects on the cardiovascular system (anti-ischemic, antiplatelet, vasodilatory), endocrine system (hypoglycemic, ACTH-stimulating), immune system (immunostimulatory, anti-inflammatory), and nervous system (CNS-stimulating and inhibiting) have been reported. Cytoprotective, cognitive, and anticarcinogenic activities are also alleged. Cytoprotective effects include resistance against ischemia, toxins, oxidation, and radiation.

Clinical Trials:

Fifty-seven randomized controlled trials (RCTs) were found in a systematic review of the worldwide clinical litera­ture, but many have significant methodologic flaws. The Chinese and Russian literatures in particular are unreliable, as method­ologic quality, flawed criteria, and publication bias are common oncerns.Therefore, double-blind RCTs in the American and Western European literature with statistically significant results are discussed here. Most of the best RCTs used a European pro­prietary product (G115, standardized to 4% ginsenosides) as either a mono-preparation or a combination product containing a mixture of vitamins and minerals (sometimes combined with deanol, or dimethylaminoethanol bitartrate) .

Physical Performance-Many controlled studies have been reviewed. Eight double-blind RCTs evaluated chronic dosing of standardized ginseng products in volunteers on cycle ergome­ters Four trials found a significant decrease in heart rate and an increase in maximal oxygen uptake, whereas the other four trials found no improvement. Evaluation of these studies does not suggest that ginseng significantly improves physical per­formance.

Cognitive Functioning-In two separate RCTs, the G115 preparation increased arithmetic calculation ability (without affect­ing other cognitive skills),16 while a different ginseng product en­hanced abstract thinking and auditory reaction times (without affecting memory or concentration)Y The combination G115 product improved cognitive functioning in middle-aged patients with mild memory impairments, but failed to improve cognition in geriatric patients. A combination ginseng/ginkgo preparation had equivocal effects on memory (beneficial effects after the lIlorning dose, but detrimental effects after the afte

many other claims, ginseng is also recommended as an aphrodisiac, for cardiovascular diseases, to prevent or treat cancers, and to prolong life. In traditional Chinese medicine, ginseng is used to restore the vital life force (qi or chi) in the body. Asian ginseng is considered more stimulating or heating (yang), while American ginseng is considered more calming or cooling (yin).

Pharmacology:

The triterpene saponins, commonly referred to as ginsenosides, are considered to be the main pharmacologic constituents of P. ginseng. At least 30 of these steroidal compounds have been described, based on their sugar side chains. The most abundant or important ginsenosides are Rg-1, Rg-2, Rb-1, Rb-2, Rc, Rd, and Rf. Like lipid-soluble steroid hormones,ginsenosides may insert into cell membranes and interact with membrane channels and proteins, or transverse the membrane to initiate genomic effects. In addition, polysaccharides, polyacetylenes, and other non-saponin constituents of P. ginseng have pharmacologic activity.

Hundreds of in vitro and animal studies, mostly from the Asian and Russian literature, have investigated the biochemical and pharmacologic activities of P. ginseng, and numerous properties have been described. For example, pharmacologic effects on the cardiovascular system (anti-ischemic, antiplatelet, vasodilatory), endocrine system (hypoglycemic, ACTH-stimulating), immune system (immunostimulatory, anti-inflammatory), and nervous system (CNS-stimulating and inhibiting) have been reported. Cytoprotective, cognitive, and anticarcinogenic activities are also alleged. Cytoprotective effects include resistance against ischemia, toxins, oxidation, and radiation.

Clinical Trials:

Fifty-seven randomized controlled trials (RCTs) were found in a systematic review of the worldwide clinical litera­ture, but many have significant methodologic flaws. The Chinese and Russian literatures in particular are unreliable, as method­ologic quality, flawed criteria, and publication bias are common oncerns.Therefore, double-blind RCTs in the American and Western European literature with statistically significant results are discussed here. Most of the best RCTs used a European pro­prietary product (G115, standardized to 4% ginsenosides) as either a mono-preparation or a combination product containing a mixture of vitamins and minerals (sometimes combined with deanol, or dimethylaminoethanol bitartrate) .

Physical Performance-Many controlled studies have been reviewed. Eight double-blind RCTs evaluated chronic dosing of standardized ginseng products in volunteers on cycle ergome­ters Four trials found a significant decrease in heart rate and an increase in maximal oxygen uptake, whereas the other four trials found no improvement. Evaluation of these studies does not suggest that ginseng significantly improves physical per­formance.

Cognitive Functioning-In two separate RCTs, the G115 preparation increased arithmetic calculation ability (without affect­ing other cognitive skills),16 while a different ginseng product en­hanced abstract thinking and auditory reaction times (without affecting memory or concentration)Y The combination G115 product improved cognitive functioning in middle-aged patients with mild memory impairments, but failed to improve cognition in geriatric patients. A combination ginseng/ginkgo preparation had equivocal effects on memory (beneficial effects after the lIlorning dose, but detrimental effects after the aft

and proteins, or transverse the membrane to initiate genomic effects. In addition, polysaccharides, polyacetylenes, and other non-saponin constituents of P. ginseng have pharmacologic activity.

Hundreds of in vitro and animal studies, mostly from the Asian and Russian literature, have investigated the biochemical and pharmacologic activities of P. ginseng, and numerous properties have been described. For example, pharmacologic effects on the cardiovascular system (anti-ischemic, antiplatelet, vasodilatory), endocrine system (hypoglycemic, ACTH-stimulating), immune system (immunostimulatory, anti-inflammatory), and nervous system (CNS-stimulating and inhibiting) have been reported. Cytoprotective, cognitive, and anticarcinogenic activities are also alleged. Cytoprotective effects include resistance against ischemia, toxins, oxidation, and radiation.

Clinical Trials:

Fifty-seven randomized controlled trials (RCTs) were found in a systematic review of the worldwide clinical litera­ture, but many have significant methodologic flaws. The Chinese and Russian literatures in particular are unreliable, as method­ologic quality, flawed criteria, and publication bias are common oncerns.Therefore, double-blind RCTs in the American and Western European literature with statistically significant results are discussed here. Most of the best RCTs used a European pro­prietary product (G115, standardized to 4% ginsenosides) as either a mono-preparation or a combination product containing a mixture of vitamins and minerals (sometimes combined with deanol, or dimethylaminoethanol bitartrate) .

Physical Performance-Many controlled studies have been reviewed. Eight double-blind RCTs evaluated chronic dosing of standardized ginseng products in volunteers on cycle ergome­ters Four trials found a significant decrease in heart rate and an increase in maximal oxygen uptake, whereas the other four trials found no improvement. Evaluation of these studies does not suggest that ginseng significantly improves physical per­formance.

Cognitive Functioning-In two separate RCTs, the G115 preparation increased arithmetic calculation ability (without affect­ing other cognitive skills),16 while a different ginseng product en­hanced abstract thinking and auditory reaction times (without affecting memory or concentration)Y The combination G115 product improved cognitive functioning in middle-aged patients with mild memory impairments, but failed to improve cognition in geriatric patients. A combination ginseng/ginkgo preparation had equivocal effects on memory (beneficial effects after the lIlorning dose, but detrimental effects after the aft

Clinical Trials:

Fifty-seven randomized controlled trials (RCTs) were found in a systematic review of the worldwide clinical litera­ture, but many have significant methodologic flaws. The Chinese and Russian literatures in particular are unreliable, as method­ologic quality, flawed criteria, and publication bias are common oncerns.Therefore, double-blind RCTs in the American and Western European literature with statistically significant results are discussed here. Most of the best RCTs used a European pro­prietary product (G115, standardized to 4% ginsenosides) as either a mono-preparation or a combination product containing a mixture of vitamins and minerals (sometimes combined with deanol, or dimethylaminoethanol bitartrate) .

Physical Performance-Many controlled studies have been reviewed. Eight double-blind RCTs evaluated chronic dosing of standardized ginseng products in volunteers on cycle ergome­ters Four trials found a significant decrease in heart rate and an increase in maximal oxygen uptake, whereas the other four trials found no improvement. Evaluation of these studies does not suggest that ginseng significantly improves physical per­formance.

Cognitive Functioning-In two separate RCTs, the G115 preparation increased arithmetic calculation ability (without affect­ing other cognitive skills),16 while a different ginseng product en­hanced abstract thinking and auditory reaction times (without affecting memory or concentration)Y The combination G115 product improved cognitive functioning in middle-aged patients with mild memory impairments, but failed to improve cognition in geriatric patients. A combination ginseng/ginkgo preparation had equivocal effects on memory (beneficial effects after the lIlorning dose, but detrimental effects after the aft

in volunteers on cycle ergome­ters Four trials found a significant decrease in heart rate and an increase in maximal oxygen uptake, whereas the other four trials found no improvement. Evaluation of these studies does not suggest that ginseng significantly improves physical per­formance.

Cognitive Functioning-In two separate RCTs, the G115 preparation increased arithmetic calculation ability (without affect­ing other cognitive skills),16 while a different ginseng product en­hanced abstract thinking and auditory reaction times (without affecting memory or concentration)Y The combination G115 product improved cognitive functioning in middle-aged patients with mild memory impairments, but failed to improve cognition in geriatric patients. A combination ginseng/ginkgo preparation had equivocal effects on memory (beneficial effects after the lIlorning dose, but detrimental effects after the afternoon dose). Overall, these studies do not suggest consistent benefits in memory, concentration, and cognitive function.

. Quality of Life (QOL)-Several placebo-controlled trials have uvaluated the G115 combination product on overall QOL (i.e., well-being) over several months. One research group found no overall benefits using two QOL questionnaires in healthy adults, and using three QOL scales measuring well-being and menopausal symptoms in perimenopausal women. Benefits were found in certain subsets of questions. Other RCTs also railed to find statistically beneficial effects for QOL, somatic symp­toms, and activities of daily living, or mood and affect. In contrast, beneficial effects were reported in two RCTs evaluating the G 115 combination product in stressed or fatigued subjects. In a study of patients diagnosed with "functional fatigue," a sig­nificant decrease in the fatigue score was seen after 6 weeks of treatment. In 625 "stressed or fatigued" adults, QOL was signifi­cantly improved compared to the vitamin and mineral components alone. Overall, no consistent benefit on QOL is discerned, although efficacy may be better in "fatigued" patients.

Immune Function-Immunologic effects have been evaluated in three RCTs over 2- to 3-month study periods. In healthy Thai students, no changes were found in total and differentialleuko­cytes, or in lymphocyte subpopulations. In contrast, G115 was reported to increase leukocyte activity, NK cell activity, and T-Iym­phocyte quantity and activity in healthy adults. In another RCT of 227 volunteers by the same investigators, G 115 signifi­cantly decreased the incidence of colds and flu (13% in the gin­seng group vs. 37% in the placebo group), and increased antibody titers.

. Endocrine-In an 8-week RCT of 36 type II diabetics, 100 or 200 mg/day of a (presumably Asian) ginseng product improved fasting blood glucose levels and HgA 1 c levels (200-mg dose only) compared to placebo. However, lack of reported data make these study results difficult to analyze. The G 115 product did not affect glucose levels measured as a secondary endpoint in a sep­arate trial of 60 healthy non-diabetics. Significant increases in sperm count and sperm motility, as well as serum testosterone, FSH, and LH levels were reported in one uncontrolled study of 66 men. However, controlled studies have failed to confirm these effects. No hormonal effects were found in an RCT of 384 peri­menopausal women with hot flashes, based on estradiol levels, FSH levels, endometrial thickness, and vaginal cytology and pH [22]. Testosterone levels were also unaffected in a 3-month RCT of 90 men with primarily psychogenic erectile dysfunction. Although improvements were reported in subjective erectile func­tioning, this study did not appear to be double-blinded.

. Miscellaneous-Ethanol consumed with 3 g of Korean gin­seng decreased serum alcohol levels in one small study, presum­ably by increasing blood alcohol clearance. In 24 patients with chronic non-viral hepatitis, a 3-month RCT found insignificant ef­fects of the G115 combination product on liver testing. In three epidemiologic studies from Korea, ginseng use was associated with a decreased risk of certain cancers (head and neck, gas­trointestinal, liver, pancreas, and lung). Epidemiologic studies cannot confirm causation, however, and all three studies were conducted by the same research group.

Adverse Effects:

Side effects appear to be mild and uncommon, and are usually similar to placebo in controlled clinical trials. Rare idiosyncratic reactions have been