There are three different herbs commonly called Ginseng: Asian or Korean ginseng (Panax ginseng), American ginseng (Panax quinquefolius), and Siberian ginseng (Eleutherococcus senticosus). The latter herb is actually not ginseng at all, but the Russian scientists responsible for promoting it believe it functions identically.
Common uses for ginseng are for cognitive disorder (antiaging effect), diabetes and cancer.
Asian ginseng is a perennial herb with a taproot resembling
the human body. It grows in northern China, Korea, and Russia;
its close relative, Panax quinquefolius, is cultivated in the United
States. Because ginseng must be grown for five years before it
is harvested, it commands a high price, with top-quality roots
easily selling for more than $10,000.
Dried, unprocessed ginseng root is called "white ginseng,"
and steamed, heat-dried root is called "red ginseng." Chinese
herbalists believe each form has its own particular benefits.
Ginseng contains many chemicals, the most important of
which are triterpenoids called ginsenosides. Different species of
ginseng contain different concentrations of the various classes
of ginsenosides.
Therapeutic Uses
Ginseng can elevate blood pressure. It has also been shown to
decrease exhaustion (fatigue) by stimulating the central nervous
system and by sparing glycogen use in exercising muscles.
Ginseng is also well known for its use in the treatment
of diabetes. It will decrease blood sugar in diabetic (but not
normoglycemic) mice. In non-diabetics, ginseng increases
blood cortisol, but it reduces serum cortisol levels in diabetics.
In vitro, ginseng has been shown to increase the lifespan of
cells (anti-aging effect).
Ginseng can reduce blood cholesterol and triglyceride
levels. Regular intake of ginseng may protect against cancer
formation; the extract and powder in people was shown more
effective than the tea, juice, or fresh sliced ginseng.
Ginseng also stimulates the immune system by enhancing
white blood cell and antibody functions. It should not be used
in high doses during acute infections as it may inhibit some
immune functions.
Dosages
Dosage in people varies based upon ginsenoside content. In
general, tonic effects are seen when the product contains at
least 10 mg of ginsenoside Rg1 to Rb1 of 1:2.
For people, the typical recommended daily dosage of
Panax ginseng is 1 to 2 g of raw herb, or 200mg daily of an
extract standardized to contain 4–7 percent ginsenosides. Eleutherococcus senticosus is taken at a dosage of 2 to 3 g whole
herb or 300 to 400 mg of extract daily. Ordinarily, a two to three
week period of using ginseng is recommended, followed by a one
to two week 'rest' period. Russian tradition suggests those under
40 should not use ginseng. Finally, because Panax ginseng is so
expensive, some products actually contain very little. Adulteration
with other herbs and even caffeine is not unusual.
Scientific Evidence
Taken together, the scientific record on ginseng is intriguing but
not conclusive. Most studies used injectable ginseng in animals
and non-double-blind studies in people. If some of the money
spent on animal and non-double-blind studies had been used
to fund more double-blind studies in humans, we might know
more. At the present it is hard to know whether ginseng is as
effective as its mystique would make it seem.
Safety Issues
Ginseng should not be used in pets with hypertension
(hyperthyroidism in cats, kidney disease in dogs and cats,
cardiomyopathy). Do not use in pets with bleeding or pets
with anxiety, hyperactivity or nervousness. Do not use in
pets taking hypoglycemic medications without veterinary
supervision. Because patients vary in their response to
ginseng, because various species of plants exist with
various quantities of ginsenosides, and because of variation
in quality control among supplements, long-term ingestion
should be avoided and veterinary advice sought when using
ginseng.
Ginseng may increase levels of digitalis drugs.
Siberian ginseng appears to have greater safety due to
standardized extracts (typically a 33 percent ethanol extract,
standardized to five percent ginsenosides). It is reported to
have antioxidant activity, lowers high blood pressure but raises
low blood pressure (an adaptogen effect), dilates coronary
arteries, and exhibits a mild diuretic effect. Side effects are
rare unless high does are used. Follow the guidelines for
Panax ginseng.
In people, unconfirmed reports suggest highly excessive
doses of ginseng can raise blood pressure, increase heart rate,
and possibly cause other significant effects. Whether some
of these cases were actually caused by caffeine mixed in with
ginseng remains unclear. Ginseng allergy can also occur, as
can allergy to any other substance. There is some evidence
ginseng can interfere with drug metabolism, specifically drugs
processed by an enzyme called "CYP 3A4." There have also been
specific reports of ginseng interacting with MAO inhibitor drugs
and also digitalis, although again it is not clear whether it was
the ginseng or a contaminant that caused the problem. There
has also been one report of ginseng reducing the anticoagulant
effects of Coumadin.
Safety in young children, pregnant or nursing women,
or those with severe liver or kidney disease has not been
established. Similar precautions are probably warranted in
pets.