Astragalus, also called milk vetch root, is the root of the Astragalus membranaceus plant, which is a member of the pea family. This perennial grows to a height of 2–4 ft. (5–10 cm). It has white or yellow flowers and leaves with 10–18 pairs of leaflets. The large yellow taproots of four- to seven-year-old plants are used for medicinal purposes. Although there are many varieties in the Astragalus family, Astragalus membranaceus is the sole medicinal type. The plant is found only in the grasslands and mountains of central and western Asia, principally in China, Taiwan, and Korea. Astragalus is a good source of selenium, an antioxidant and immune system stimulant.
Astragalus is called Huang Qi in traditional Chinese medicine (TCM) and is considered to be an important tonic herb. It is used to strengthen what is called the wei qi, or the defensive energy of the body against disease. TCM identifies astragalus as being helpful in conditions involving the Spleen, the Lungs, and the Triple Burner. It is a warming tonic, and it improves the functioning of the qi (the flow of energy in the body), the Spleen, the Blood, and the fluids of the body. Astragalus is recommended for Spleen deficiency symptoms, such as diarrhea, fatigue, sweating, and lack of appetite. It is used as a tonic for the Lungs and is good for shortness of breath, asthma, and chronic lung problems. Astragalus is prescribed for arthritis, diarrhea, and nervous symptoms. It is often given to people who are in a state of generally poor or weakened health.
Astragalus is classified as an adaptogen, an herb that increases the body's endurance and resistance to a wide array of physical, chemical, and biological stressors. Adaptogens help normalize the functioning of various body systems by affecting the action of hormones. Adaptogens are usually beneficial in treating chronic conditions. They have been found to enhance the immune response, reduce inflammation, stabilize blood sugar, and support the hormone systems, particularly the adrenal and pituitary glands. Adaptogens should be used for an extended period of time—at least six weeks.
Astragalus helps the body function at its best level. It helps the body deal with stress and enhances overall immune function. It has been shown to stimulate production and activation of the white blood cells, which fight infection. It is highly recommended for preventing and alleviating colds and flu. Astragalus can be used to cure chronic weaknesses of the lungs. Because it improves blood circulation and heart function, astragalus is useful in treating heart disease. It has also been found to prevent or reduce blood clotting. Astragalus can be taken as a tonic for the kidneys. It has a diuretic (urine-producing) effect and so it flushes out the urinary system. It is thus very effective in treating kidney infections, proteinuria (too much protein in the urine), chronic prostate problems, and chronic urinary tract problems.
Astragalus is helpful to those taking chemotherapy and radiation treatments. It reduces toxic side effects and enhances therapeutic effects. Cancer patients who take astragalus during or after cancer treatments tend to recover more quickly from the ill effects of the treatment, and they generally have better survival rates. This appears to be connected with the strengthening of the immune system. Astragalus also stimulates the adrenal glands, whose functions are suppressed in cancer. The herb improves poor appetite, diarrhea, weakness, wasting, and night sweats. This makes it helpful for cancer patients as well as AIDS sufferers and those with other debilitating diseases.
Astragalus is recommended as a tonic for the elderly. It protects cells from the aging process and may diminish other negative effects of aging. For example, it strengthens digestion, stimulates the appetite, and helps improve mental functioning. Astragalus shows promise in the treatment of Alzheimer's disease. By itself or in combinations, it may be useful in treating viral infections, hypoglycemia, diabetes mellitus, chronic ulcers, insomnia, hyperthyroidism, chronic fatigue syndrome, open wounds, liver problems, sexual dysfunction, fertility problems, and autoimmune diseases.
Astragalus is available as a capsule, a tablet, a tincture, as a part of an herbal combination, as a prepared tea, and as a sweet dried root that can be eaten or made into tea. Traditionally, several slices of the root are often added to soups and stews. A strong tea can be made by boiling three ounces of astragalus root in three cups of water and letting the mixture steep for at least five minutes. Two or three cups of the unheated tea can be taken over the course of a day. In tincture form, 30–60 drops of astragalus can be taken four times per day. Candied roots can be purchased ready-made or prepared in the home. Preparation involves combining four parts of the dried root with one part honey in water, then simmering until the herb is dried and brownish. In TCM, astragalus ointments are used to heal wounds, particularly those that are slow to heal.
Since astragalus is a warming herb, its use should be avoided in heat conditions, such as fevers or agitated states. Astragalus membranaceus is the only species of its family to have a medicinal use; other species may be toxic. Therefore, local Western varieties should not be used. Use only the root portion of the plant; other parts of the plant may be poisonous.
Sometimes individuals experience a slight stomach upset or allergic reaction to astragalus. However, it is generally a very safe herb, even at high doses.
Astragalus increases the effectiveness of other herbs when used in combinations. It is often used with Siberian ginseng, Eleutherococcus senticosus; Echinacea spp.; dong quai, Angelica sinensis; and Lingusticum wallichi. Astragalus may interfere with the actions of diuretics, phenobarbital, beta-blockers, and anticoagulants (substances that prevent blood clotting). Users of these medications should consult a healthcare provider before using the herb.
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