Asian Ginseng - Medicinal Uses, Interactions, Side Effects, Dosage
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 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 reported, such as Stevens-Johnson syndrome and cerebral arteritis.
Estrogen like properties such as vaginal bleeding and mastalgia have been associated with ginseng use in isolated reports.
However, a cause and effect relationship is doubtful, as controlled clinical studies of standardized products have not demonstrated hormonal effects.
Many of these reactions are most likely due to adulteration or contamination by unrelated herb or drug products, which has been well described with many Asian herbal medicines.
CNS-stimulation and a "ginseng abuse syndrome" (hypertension, nervousness, insomnia, skin eruptions, and morning diarrhea) were described in 10-20% of chronic ginseng users in an uncontrolled survey of psychiatric patients in 1979.
These adverse effects have not been observed in controlled studies, and this "syndrome" is probably nonexistent.
However, several Asian ginseng supplements have been reported to contain significant amounts of methylxanthines, and CNS-stimulation has been reported with ginseng use in other psychiatric patients.
Side Effects and Interactions: Asian ginseng appeared to inhibit the effects of warfarin in one patient, although no interaction could be detected in a rat model.
Ginseng combination products were loosely associated with stimulant or manic effects in two patients taking phenelzine, a monoamine oxidase inhibitor.
Overall, interactions do not appear to be a significant concern, but data is limited.
Cautions: Adulteration or contamination with drugs (e.
g.
, steroids, stimulants, sedatives), pesticides, and heavy metals has been well described for many Asian herbal medicines, and is a particular concern for pregnant and nursing women.
Although caution in using ginseng during pregnancy and breast-feeding is advisable, in a survey of 88 women who consumed ginseng during pregnancy, reproductive outcome was no different than matched controls.
No mutagenic, carcinogenic, teratogenic, or adverse reproductive effects are seen in animal models.
Preparations & Doses: Ginseng is commercially available as the whole or powdered root, in capsules and tablets, as teas, candies, and in many other forms.
In traditional Chinese medicine, 10 g or more may be employed, usually in combination with other herbs.
In Western herbal medicine, 1-2 g/day of a crude or powdered root preparation is commonly used.
Commercial extract products (standardized to 4% ginsenosides) are usually dosed as 100 mg b.
Ld.
, which is equivalent to about 1 g/day of ginseng rooP The proprietary extract examined in many controlled trials (G115, standardized to 4% ginsenosides) is marketed in the U.
S.
as Ginsana, and the product combined with vitamins and minerals as Vitasana (Pharmaton Natural Health Products).
The American Botanical Council's Comprehensive Ginseng Evaluation Program recently analyzed 13 commercially available "standardized" Asian ginseng products for lot-to-lot consistency.
Most products were reasonably consistent, but the ginsenoside content of a few products was more variable.
SummaryEvaluation Asian ginseng is claimed to have multiple pharmacologic and clinical effects, most of which have not been established in rigorous controlled trials in the Western literature.
Although some controlled studies have reported potential benefits, many others offer contrasting results and thus provide little convincing evidence.
The overall evidence does not support claims that Asian ginseng can reliably improve physical performance, cognitive functioning, and quality of life.
Beneficial effects on fatigue, diabetes, and viral URIs have been demonstrated in single or limited clinical trials, but in general, the efficacy of Asian ginseng is not established beyond a reasonable doubt for any indication.
Side effects appear to be rare.
Although millions of people have taken ginseng daily for years, suggesting that it is very benign, adulteration or contamination of Asian ginseng products with unwanted substances is concerning.
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 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 reported, such as Stevens-Johnson syndrome and cerebral arteritis.
Estrogen like properties such as vaginal bleeding and mastalgia have been associated with ginseng use in isolated reports.
However, a cause and effect relationship is doubtful, as controlled clinical studies of standardized products have not demonstrated hormonal effects.
Many of these reactions are most likely due to adulteration or contamination by unrelated herb or drug products, which has been well described with many Asian herbal medicines.
CNS-stimulation and a "ginseng abuse syndrome" (hypertension, nervousness, insomnia, skin eruptions, and morning diarrhea) were described in 10-20% of chronic ginseng users in an uncontrolled survey of psychiatric patients in 1979.
These adverse effects have not been observed in controlled studies, and this "syndrome" is probably nonexistent.
However, several Asian ginseng supplements have been reported to contain significant amounts of methylxanthines, and CNS-stimulation has been reported with ginseng use in other psychiatric patients.
Side Effects and Interactions: Asian ginseng appeared to inhibit the effects of warfarin in one patient, although no interaction could be detected in a rat model.
Ginseng combination products were loosely associated with stimulant or manic effects in two patients taking phenelzine, a monoamine oxidase inhibitor.
Overall, interactions do not appear to be a significant concern, but data is limited.
Cautions: Adulteration or contamination with drugs (e.
g.
, steroids, stimulants, sedatives), pesticides, and heavy metals has been well described for many Asian herbal medicines, and is a particular concern for pregnant and nursing women.
Although caution in using ginseng during pregnancy and breast-feeding is advisable, in a survey of 88 women who consumed ginseng during pregnancy, reproductive outcome was no different than matched controls.
No mutagenic, carcinogenic, teratogenic, or adverse reproductive effects are seen in animal models.
Preparations & Doses: Ginseng is commercially available as the whole or powdered root, in capsules and tablets, as teas, candies, and in many other forms.
In traditional Chinese medicine, 10 g or more may be employed, usually in combination with other herbs.
In Western herbal medicine, 1-2 g/day of a crude or powdered root preparation is commonly used.
Commercial extract products (standardized to 4% ginsenosides) are usually dosed as 100 mg b.
Ld.
, which is equivalent to about 1 g/day of ginseng rooP The proprietary extract examined in many controlled trials (G115, standardized to 4% ginsenosides) is marketed in the U.
S.
as Ginsana, and the product combined with vitamins and minerals as Vitasana (Pharmaton Natural Health Products).
The American Botanical Council's Comprehensive Ginseng Evaluation Program recently analyzed 13 commercially available "standardized" Asian ginseng products for lot-to-lot consistency.
Most products were reasonably consistent, but the ginsenoside content of a few products was more variable.
SummaryEvaluation Asian ginseng is claimed to have multiple pharmacologic and clinical effects, most of which have not been established in rigorous controlled trials in the Western literature.
Although some controlled studies have reported potential benefits, many others offer contrasting results and thus provide little convincing evidence.
The overall evidence does not support claims that Asian ginseng can reliably improve physical performance, cognitive functioning, and quality of life.
Beneficial effects on fatigue, diabetes, and viral URIs have been demonstrated in single or limited clinical trials, but in general, the efficacy of Asian ginseng is not established beyond a reasonable doubt for any indication.
Side effects appear to be rare.
Although millions of people have taken ginseng daily for years, suggesting that it is very benign, adulteration or contamination of Asian ginseng products with unwanted substances is concerning.