Astringent herbs are not uncommon at all and they have a very simple action in the body. Most astringent actions are attributed to a class of molecules called tannins. These molecules ‘tan’ the tissues they come in contact with, such as the digestive system if you drink an herbal tea containing tannins.
The tanning action of tannis generally is a binding together of proteins to make a uniform wall of proteins which other molecules cannot pass through. If you know a few things about the digestive system, you can probably see how this could easily become bad. This is one reason why individuals who drink high amounts of coffee regularly may have digestive upset-they are no longer to properly absorb their foods.
Topically, astringent herbs can be great to help stop bleeding but why would you want to use these internally? Well, the same reason of course! Internal bleeding, weak tissues that some stability, protecting from an infection and reducing inflammation locally. Most astringents have their action on the digestive system but a few are thought to also help the urogenital systems. Long term use of astringents is highly discouraged due to their tanning effect.
Yarrow is often called a styptic herb, meaning it helps reduce bleeding. This is the case for both topical and internal usage in the digestive tract. When there is excess fluid in the lungs, yarrow is also recommended to help dry up the mucus. This is called an anticatarrhal property. Yarrow also has astringent properties for the urinary tract where it is also an effective antiseptic. This herb is in the aster family which can cause irritation for some individuals who are sensitive to all plants in this family.
Red Raspberry is most often thought of as an astringent for the uterine lining, commonly a ‘female herb.’ For the uterus, raspberry can help to strengthen and tone the tissue, making it ideal for women trying to get pregnant. It however should not be used during pregnancy itself as it may encourage contractions during labor. During desired labor, raspberry may be used to reduce hemorrhaging.
This is the one herb I will discuss today that’s action is solely on the digestive system. While sage is a great astringent for the digestive system, to help firm up tissues, it does not have some of the long term issues because sage is also a stimulating herb that increases blood flow to the digestive lining. This will encourage continued absorption of nutrients while firming the digestive lining. Sage is also a great antimicrobial for the digestive tract if you have the worry of pathogens or unhealthy bacteria living in you colon.
For more information on herbal actions such as astringent herbs, please consult the book “Medical Herbalism” by David Hoffmann. If you are interested in using these and other herbs on a daily basis, please consult with a professional herbalist.