Astragalus

Astragalus is an important traditional Chinese medicine that has been prescribed for centuries for general debility and chronic illnesses, as well as to increase the body’s overall vitality. Today, research has confirmed that astragalus provides numerous potential therapeutic applications in immunodeficiency syndromes, as an adjunct cancer treatment, and for its adaptogenic (normalizing) effect on the heart and kidneys. Astragalus appears to be most effective when used on a long-term basis daily.1-6

Scientific studies have found astragalus acts as an adaptogen, antioxidant, cardiotonic, diuretic, immunostimulant and tonic. Astragalus also controls excessive perspiration, lowers blood pressure and blood sugar levels, strengthens digestive function, and improves circulation in the flesh and skin. Astragalus has been used clinically for AIDS, adrenal deficiency, sluggish appetite, bronchitis, cancer, cardiovascular disease, the common cold, diabetes, edema, chronic fatigue, hepatitis (liver inflammation), hypertension (high blood pressure), chronic or recurrent infections, influenza (flu), slow-to-heal lesions, cold and weak limbs, nephritis (kidney inflammation), profuse perspiration, prolapse of internal organs, and viral myocarditis (a flu-like infection that affects the heart).2,3,5,7,8

Astragalus’s profound effects on the immune system make it especially useful in preventing colds and flu and in treating chronic or recurrent infections. Chinese research has shown that astragalus helps the body resist viral infections, particularly in the lungs, by increasing production of interferon, an immune factor that inhibits viral growth. In fact, clinical studies have proven the effectiveness of astragalus when used to prevent the common cold, as well as its ability to reduce the duration and severity of symptoms in acute treatment of the common cold. Astragalus has also demonstrated in vitro antibacterial activity against Shigella dysenteriae, Streptococcus hemolyticus, Diplococcus pneumonia and Staphylococcus aureus.1,3,4,7,8

Animal research has shown that astragalus achieves its wide range of immune-enhancing effects by stimulating various key immune system parameters, including facilitating the activity of macrophages (immune cells that ingest foreign invaders); enhancing interferon production and the secretion of tumor necrosis factor (TNF); increasing natural killer (NK) cell and T-cell activity; stimulating antibody production; increasing levels of immunoglobulins; and potentiating other antiviral mechanisms. More recent in vitro animal studies have confirmed earlier findings showing that astragalus suppressed tumor growth and restored immune function compromised by tumor growth. 6,7,9-11

Human clinical studies have also confirmed astragalus’s immune-potentiating effects. For example, astragalus has been shown to enhance the induction of interferon by peripheral white blood cells after only 2 weeks of daily intake. Astragalus was also found to stimulate natural killer (NK) cell activity in patients with systemic lupus erythematosus.4,5,12

Astragalus demonstrates particular usefulness in cases where the immune system has been compromised by chemicals or radiation. Clinical studies have proven the herb’s effectiveness as an adjunct cancer therapy—astragalus improves tolerance and minimizes the toxic effects of chemotherapy and radiation, as well as speeds recovery and improves survival rates for cancer patients undergoing such therapy. In one clinical study of 115 patients taking chemotherapy, astragalus increased white blood cell counts by nearly 83%. It is important to note that astragalus does not contain components that directly attack cancer cells, but rather, strengthen the body’s own immune defenses against the development of cancer. Of course, astragalus is also recommended for patients who have impaired immunity due to chronic disease states.1-3,6-9,13

There is also evidence that astragalus offers therapeutic benefit for the treatment of cardiovascular disease. Various phytonutrients in astragalus—saponins, flavonoids and GABA—help explain the herb’s cardiovascular effects, including the ability to reduce oxidative damage. In addition, astragalus flavonoids are well-known to help prevent platelet aggregation (blood clotting). Since Chinese researchers have experienced significant preliminary results using astragalus preparations administered by injection or intravenous infusion, several researchers have proposed that astragalus may be used clinically as an immunotonic and adaptogen in patients suffering from angina, arrhythmias, congestive heart failure (CHF), edema, hypertension, acute myocardial infarction (heart attack), nephritis and vascular insufficiency. In one clinical trial using an oral astragalus extract, patients suffering from viral myocarditis demonstrated significantly enhanced immune response.3-5,7,14,15

Other animal studies have demonstrated that astragalus improves memory and energy metabolism in mice, improves wound healing and the healing of peptic ulcers, and is useful in treating hepatitis and nephritis and protecting against both. Incidentally, astragalus is widely used in China in the treatment of chronic hepatitis.3,4,7

Astragalus is very safe overall and doses as high as 100g/kg of the raw herb have been given to rats by lavage with no adverse effects. Although there are no known side effects, astragalus is not recommended for acute inflammatory, infectious states and high fevers—it is best to avoid use until the condition is downgraded. Astragalus may be incompatible with immunosuppressive agents and may not be appropriate for the treatment of autoimmune diseases or following organ transplantation.1,4-7