General Description
Astragalus, also known as huang qi, is a perennial herb native to
Northern China, Japan, Tibet, and Korea, where it grows in grasslands
and well-drained woodlands. A member of the legume family, astragalus
grows up to 1 meter in height with rigid stalks that sprout eight
to twelve pairs of leaflets. The plant has small yellow blossoms,
and bears its seeds in short, pea-like pods. The root of the plant,
which has a fleshy, pale yellow center with a sweet, licorice-like
flavor, is used for medicinal purposes.
Health Applications
- Immune system support
- Cardiovascular health
- Fatigue
- Liver health
History and Traditional Use
Astragalus root has a history of medicinal use that dates back over
2,000 years. A mainstay of Traditional Chinese Medicine (TCM), astragalus
is valued as a "chi" herb—an energizing tonic and immune system
booster. TCM practioners use astragalus, often in combination with
several other herbs, for a wide range of applications including
diarrhea, night sweats, diseases of the kidneys and spleen, circulatory
disorders, and infections.
Chemical Composition
Astragalus root contains a variety of compounds including isoflavones
and other flavonoids, polysaccharides, astragalosides, essential
fatty acids, saponins, beta-sitosterol, betaine, and choline.1
Astragalus extracts are commonly standardized for isoflavone content.
Immune System
Support
Modern use of astragalus root has centered on the herb's reputation
as an immune system booster and overall tonic. Numerous in vitro
studies indicate that components found in astragalus root stimulate
immune response and enhance natural killer cell activity, suggesting
potential for the herb in the treatment of cancer and HIV;2-8
however, the efficacy of the herb for these purposes has not been
demonstrated in human trials. Although astragalus has gained popularity
as an herbal cold and flu remedy, there is no scientific data
to support such use.
Cardiovascular
Health
Astragalus has traditionally been used as a heart tonic, and research
indicates there may be some merit to this application. Studies
on patients with coronary heart disease indicate that astragalus
can improve sodium pump activity and lower red blood cell sodium
levels,9 relieve angina, and improve heart function.10
In one study conducted on patients with congestive heart failure,
a compound isolated from astragalus root (astragaloside IV) was
found to improve heart function and exercise tolerance.11
Another study conducted on 43 heart attack patients showed that
astragalus improved heart strength and reduced lipid peroxidation,
suggesting that the cardiovascular benefits of astragalus root
may stem from its antioxidant activity.
Dosage/Toxicity
In traditional Chinese medicine, the daily recommendation is a
decoction made from 9 to 15 grams of the dried root.1
Astragalus root capsules are commonly taken in doses ranging from
2 to 3 grams per day. For standardized extracts, 1,000 mg per
day is a common recommendation. Astragalus is not associated with
any toxicity in this dosage range. Astragalus should not be
used by organ recipients taking antirejection drugs, as it may
interfere with the drugs' activity. |
