Our immune system is hard-working in its efforts to protect and defend against invading foreign substances, microorganisms and toxins. Ensuring that the immune system is working optimally is the key to a healthy immune response. Traditional herbal medicines such as Astragalus membranaceous (astragalus) have been demonstrated to support a healthy immune system.
Fewer herbs are held in higher esteem in traditional Chinese medicine (TCM) than astragalus, where it is considered a master immune herb. Astragalus has been prescribed in TCM for thousands of years and is an important qi tonifier (qi meaning the vital life force). Astragalus is now a favoured herb in western herbal medicine due to its supportive effect on the immune system.
Human, animal and in vitro studies, from the Peking University Health Science Center, Beijing, have shown that astragalus effectively fosters immune system health by improving many aspects of its function including B and T lymphocyte activity; immune cells that are responsible for defence and fighting off infections.[1,2] Astragalus has also been shown to help with balancing inflammatory cytokines, also involved in a healthy immune response.
Acute stress can prepare and enhance the immune system during the sympathetic ‘fight or flight’ response. It is important to maintain healthy stress levels long-term, to ensure immune cells function as best they can. Some ways to ensure stress is managed well include consuming a healthy balanced diet including protein, wholegrains, fruit, vegetables and good fats. Plenty of sleep is also vital e.g. at least eight hours per night, while meditation, yoga, mindfulness exercises and social interactions with friends and family can also be helpful.
Polysaccharides are one of the main active plant chemicals responsible for astragalus’ immune actions in the body. Interestingly, polysaccharides may positively influence gastrointestinal (GIT) flora, which in turn may improve immune function. Healthy microflora balance in the GIT can help the body to fight infection, and boost the immune system. Animal and in vitro studies have shown that astragalus polysaccharides increase beneficial GIT bacteria, while reducing unhelpful microflora.
- Braun L, Cohen M. Herbs and natural supplements: an evidence-based guide, 4th ed. Sydney: Churchill Livingstone Elsevier, 2015. [Full Text]
- Shao BM, Xu W, Dai H, et al. A study on the immune receptors for polysaccharides from the roots of Astragalus membranaceus, a Chinese medicinal herb. Biochem Biophys Res Commun 2004;320(4):1103-1111. [Abstract]
- Jin M, Zhao K, Huang Q, et al. Structural features and biological activities of the polysaccharides from Astragalus membranaceus. Int J Biol Macromol 2014;64:257-266. [Abstract]
- Morey JN, Boggero IA, Scott AB, et al. Current directions in stress and human immune function. Curr Opin Psychol 2015;5:13-17.s [Full Text]