Dr. Oz likes the herb astragalus. He says that it "actually slows down the aging process right where it happens, inside of our cells, where the blueprint of our cells resides." This is based on some preliminary experiments that show astragalus may boost the formation of the enzyme telomerase that protects DNA from unraveling. But suggesting that this test tube observation means it can prevent aging is a stretch. Astragalus root, though, is interesting. In China, it is sometimes is scraped into snake soup to treat the common cold because it is said to increase qi! I’m not exactly sure what qi is. It doesn’t really fit into any scientific concept. According to ancient Chinese medicine, qi is the body’s defensive energy, the energy needed to fight disease. If the flow of qi is impaired, disease takes a foothold. If we were to look for a western parallel, I suppose it would be the “immune system.” Astragalus is supposed to boost qi, or in other words, increase the activity of the immune system. Does it? That’s not an easy question to answer.
First we have the usual problem associated with any herbal remedy. The composition of the root is incredibly complex. There are saponins, polysaccharides, flavonoids, amino acids, phenolic acids and dozens and dozens of other compounds. Without a doubt, many of these have physiological activity. A polysaccharide called astragalan B, for example, has been shown in animal studies to stimulate the immune system and control bacterial infections. It also has antiviral activity and inhibits viral replication in mice infected with the coxsackie virus which can attack heart tissue. In laboratory studies astragalus increases natural killer cell and T cell function as well as interleukin-2 activity which suggests that it should be beneficial in conditions such as hepatitis, cancer and even AIDS.
The long history of safe use of astragalus and the intriguing animal and laboratory studies have spurred some human trials. Early trials on cancer patients have provided some interesting results. Radiation and chemotherapy reduce the body’s natural immunity which can cause a variety of problems. But when astragalus is used, patients recover faster. In China, astragalus is commonly used in conjunction with radiation and chemotherapy. Astragalus may also have an effect on heart disease. Chinese studies have shown that taken within 36 hours of a heart attack, astragalus increases the pumping ability of the heart’s left ventricle, the part of the heart often damaged in a heart attack. Furthermore, astragalus was shown to prevent angina with an effectiveness comparable to that of nifedipine.
All of this sounds very interesting, but it is still very preliminary with respect to the kind of proof we would like to see before making specific recommendations about the use of astragalus. We would like to see standardized products that show effectiveness in repeated trials. The studies carried out so far have used various preparations and various doses. We would like to know that there are no interactions with prescription drugs. For example, astragalus does have some anticoagulant activity so it may interact with coumadin. We don’t know how it reacts with anesthetics, so it would be wise to avoid astragalus before surgery. Astragalus may interact with medications that suppress the immune system, such as cyclophosphamide and may also affect blood sugar levels and blood pressure. Anyone undergoing radiation or chemotherapy may want to discuss the possible use of astragalus with their physician, although the likely answer they will get is that there just isn’t enough information available to make a scientific recommendation.
But if you feel a cold coming on, scraping a few grams of astragalus root into tea or chicken soup may be worth a try. Capsules of the root are available as well. A guess is that 800-1000 mg a day may be helpful. Remember, though, that regulations for such products are lax and there’s no guarantee that what is claimed on the label is really in the bottle. If the decision about whether or not to try astragalus causes stress, well, the Chinese say that astragalus is one of the best antidotes to the health-damaging effects of stress.