Chinese characters are stylized pictures with several layers of meaning, which makes the writing and interpretation of these characters a complex art form. Two characters make up the written Chinese word for astragalus, huang-qi. The top character, “huang,” means yellow, the bottom, “qi,” means venerable, according to Kai-Ho Mah, a calligrapher and professor of foreign languages and Asian studies at Colorado State University.
For the Chinese, yellow is the color of life-giving earth, he says, and this quality is reflected in the huang character’s depiction of a fence above a square rice paddy, beneath which are two marks indicating the sweat from labor.
Qi shows the crosslike forms of two plants atop the character lao, translated as aged and venerated. Lao in turn sits above a square-shaped sun.
Together, these symbols mean a plant both venerated and good for the elderly, one that will bring many more days. The sound “qi,” when pronounced with different intonations, also means vital force, addiction to sensory pleasures, and to eat—all meanings that factor into the idea that astragalus increases vitality and overall health.
In the ancient Chinese herbal Shen Nong Ben Cao Jing, under the category of superior herbs, there is a listing for a plant known as huang-qi, praised for its ability to fight fatigue and general debility.
Today, Westerners know this herb as astragalus, and scientists are learning that the lessons of ancient cultures are not to be dismissed. Modern research shows that astragalus’s reputation can be attributed to compounds that boost the immune system and help many people in distress, including cold-sufferers and chemotherapy patients.
Astragalus (Astragalus membranaceus) is the common English name for huang-qi. One interpretation of the word is that “huang” means yellow, referring to the yellow interior of the herb’s root, and “qi” means leader, referring to this herb’s place as a superior tonic in Chinese medicine.
A. membranaceus grows in China from the northeastern province of Heilongjiang, south to the Shandong peninsula, west to the mountains of Sichuan, and north to the westernmost province of Xinjiang. It is found along forest margins, in shrub thickets, thin open woods, and grasslands near the edge of forests. The Chinese harvest its roots when plants are four to five years old. Before completely dry, the roots are sliced into thin diagonals or sliced lengthwise, producing a dried product that looks like a tongue depressor.
The astragalus genus is one of the largest groups of flowering plants, with more than 1,750 documented species and members; some are merely ornamental, some are medicinal, and some are poisonous. In the United States, the astragalus genus is best known for producing “locoweed.” Woolly loco (A. mollissimus), which grows abundantly in New Mexico and Texas, is one of the first plants to produce foliage in the spring. When livestock eat this plant, it can be harmful and even fatal. Locoism causes structural changes in nerve cells and makes animals behave strangely. They may develop a craving for the plant and refuse to feed on other forage, which can lead to death from starvation. Locoism can affect horses, cattle, prairie dogs, and even bees.
Other astragalus species are considered safe and used in foods, cosmetics, and coffee or tea substitutes. Gum tragacanth—a common colloidal ingredient in lotions, pharmaceutical suspensions, resinous tinctures, creams, jellies, and ice cream—is derived from several astragalus species.
Westerners began to realize the medicinal importance of A. membranaceus during the 1800s. The species was first described for the West in 1868 by Dr. Alexander von Bunge, a Russian physician who studied East Asian plants. In the Chinese Materia Medica of 1911, G. A. Stuart wrote that astragalus “is in great repute as a tonic, pectoral, and diuretic medicine, the diseases for which it is prescribed, therefore, are almost numberless.”
According to various books on Traditional Chinese Medicine, astragalus invigorates vital energy (qi) and strengthens bodily resistance. Health practitioners have prescribed it to treat shortness of breath, general weakness, and lack of appetite, and have recommended it as a diuretic as well as to treat colds, flu, stomach ulcers, and diabetes.
Astragalus is becoming one of the better-known Chinese herbs. Some of its popularity may be attributed to extensive scientific study that began in the 1970s. Laboratory and clinical studies confirm the herb’s ability to stimulate the immune system, fight bacteria, viruses, and inflammation, protect the liver, and act as a diuretic and adaptogen. Adaptogens are substances that have nonspecific actions and cause minimal disruption to the body while normalizing body functions, no matter the condition or disease.
Astragalus is one of many herbs used in Chinese fu-zheng therapy, which treats disease by enhancing or promoting the body’s defense mechanisms. In the West, we describe this process as stimulating or enhancing the immune system. Scientists are tracing the immune-boosting abilities of astragalus to chemicals in the plant known as polysaccharides, especially astragalan I, II, and III, and saponins and triterpenes.
Scientific interest in astragalus was stimulated by Chinese research groups during the mid-1970s. The researchers were trying to verify, through laboratory and clinical tests, a basis for the ancient practice of fu-zheng and to determine whether astragalus had value for modern medicine.
In modern China, three systems of medicine are recognized—modern Western medicine, the ancient system of Traditional Chinese Medicine, and a combination of the two. It was in the context of the combined Chinese and Western medical traditions that researchers sought answers.
The researchers knew that chemotherapy and radiation treatments tend to suppress the immune system of cancer patients, making them more susceptible to other illnesses. So they studied the potential of astragalus to increase these patients’ immunity. The researchers began their work in 1975, and during the late 1970s and early 1980s, they published several studies that outlined their findings. According to the studies, astragalus encourages bone marrow, otherwise depressed by chemotherapy and radiation, to produce more white blood cells, the immune system’s first line of defense. It also increases the ability of these cells to engulf invading particles such as bacteria and viruses. The researchers also reported that astragalus mitigates gastrointestinal poisoning in patients undergoing conventional cancer therapies. The result was a significant increase in survival rates for the patients receiving both the fu-zheng therapy and Western cancer treatments.
Astragalus can help boost the immune system in other situations as well, apparently by supporting the body’s natural killer cells. Some studies have focused on the herb’s ability to fight viruses, but it hasn’t been effective against HIV, the virus that causes AIDS.
Other studies conducted during the past thirty years show that the root acts as a diuretic to help flush the system. And when mice were given a decoction of the root during a three-week period, their swimming time increased, as did their body weight, suggesting that the root has an adaptogenic effect. Other experiments show that astragalus can help reduce blood pressure, dilate blood vessels, and improve circulation. Since the early 1990s, several Asian research groups have conducted studies showing that astragalus root protects the liver from toxic compounds.
It’s tempting to believe that we are only now documenting something that the Chinese have known for centuries—that astragalus is a superior class of herb. But we’re just beginning to understand how it works, and its acceptance by practitioners of Western medicine will likely depend on the outcome of additional well-designed, controlled clinical trials. 8
What it does: Stimulates the immune system.
How we know: In some studies, astragalus has been shown to boost the immune system of patients undergoing chemotherapy and radiation treatments. Chinese studies show that astragalus can increase the ability of white blood cells to engulf microbes and other antigens.
Dosage: In Traditional Chinese Medicine, astragalus is often used in daily doses of 9 g to 15 g of the dried sliced root, simmered for several hours in a quart of water (the decoction is ready when the water is reduced down to a pint).
Astragalus tinctures, tablets, and capsules are available on the American market, where it is often combined with ginseng. Typically, capsules deliver a dose of up to 500 mg. Two average capsules three times a day equal a dose of 3 g. For commercial products, follow manufacturers’ instructions listed on the label.
Cautions: Astragalus has no known side effects.
Steven Foster is an herbalist, author, and photographer who lives in Fayetteville, Arkansas. An Herbs for Health editorial adviser, he is a frequent contributor to the magazine. His latest book is 101 Medicinal Herbs: An Illustrated Guide (Interweave, 1998).
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