Long-time readers know that my “go-to” sources for natural medicines (herbs, vitamins, and supplements) are ConsumerLab.com and Natural Medicines(TM). ConsumerLab has posted about coronavirus and astragalus:
Astragalus (or Huang qi) has been promoted on some websites to help protect against COVID-19.
Astragalus is an herb that has traditionally been used in Chinese medicine to strengthen the immune system and to treat colds, among many other uses. It may be sold as a root powder, extract or tea, as a single ingredient or as part of an “immune-boosting” formula.
Laboratory and animal studies suggest polysaccharides, astragalosides and other compounds in astragalus increase the production of white blood cells, particularly T cells and macrophages, and other cells important for immune system function (Block, Integr Cancer Ther 2003).
It has also been shown to have anti-inflammatory and anti-viral effects, including activity against a particular type of coronavirus that commonly infects poultry (Jin, Int J Biol Macromol 2014; Zhang, Microb Pathog 2018).
In China, astragalus, alone and in combination with other herbs, has been suggested to potentially help prevent COVID-19 infections (Yang, Int J Biol Sci 2020).
However, there is no clinical evidence at this time that astragalus can prevent or treat coronavirus infections in people.
Many of the studies of astragalus supplementation in people have been conducted in China, and in some cases, complete translations of these studies, or details about the formulations used, are not available.
An observational study of 1,000 people in China reported that astragalus given orally, or as a nasal spray, was associated with reduced the incidence and duration of colds, but the exact preparation and dosage of astragalus is not known — nor do observational studies prove a cause-and-effect relationship (Chang, Pharmacology and Applications of Chinese Materia Medica 1987).
A very small study (14 individuals in China) found that astragalus extract (equivalent to 8 grams of root powder per day) increased the production of interferon and leukocytes (which typically increase in response to exposure to viruses) compared to placebo (Hou, Zhonghua Weisheng Wuxue Hemian Yixue Zazhi 1981).
There appears to be insufficient research to determine whether astragalus can help prevent viral respiratory tract infections in children (Su, Cochrane Database Syst Rev 2016).
Some researchers have advised that a daily dose of 4 to 7 grams of root powder may be the best dosage for increasing macrophage activity while higher dosages (28 grams or more per day) may suppress the immune system.
Due to its immune-stimulating effects, people with autoimmune disease and those taking immunosuppressant drugs (such as after organ transplantation) should not take astragalus.
Astragalus polysaccharides may stimulate histamine release, which could increase allergic reactions in some people (Upton, Astragalus Root Monograph American Herbal Pharmacopoeia 1999).
With regard to COVID-19, an immune-stimulating effect may be helpful in fighting infection, but it could, theoretically, accelerate the lower respiratory “cytokine storm” believed to ravage the lungs in severe cases.
This herb may also lower blood pressure, and so should be used with caution in people with low blood pressure and those taking blood pressure-lowering medications.
Women who are pregnant or breastfeeding should not take astragalus. The development of liver and kidney cysts associated with drinking astragalus tea and taking astragalus powder has been reported in one woman in China (Tond, J Clin Pharm Ther 2014).
Of course, the most important thing you can do to avoid infection with coronavirus is to prevent exposure by following the latest recommendations of the CDC and World Health Organization and take steps to stay healthy, including getting adequate sleep, keeping up with your daily exercise, and eating a healthy nutritious diet.
© Copyright WLL, INC. 2020. This blog provides a wide variety of general health information only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment from your regular physician. If you are concerned about your health, take what you learn from this blog and meet with your personal doctor to discuss your concerns.