Research 1 Herb
by Paul Bergner
Inulin is major constituent of some of the most famous of the "old-standby" herbs, such as burdock root, dandelion root, elecampane root, chicory root, and the Chinese herb codonopsis. Botanically, inulin is a storage food in the plants of the Composite family. Inulin when injected interacts with complement system, which has resulted in rumors in herbal circles that it is immunostimulant. It is not digested or absorbed, however, (except perhaps in mico-amounts) and such effects are not observed with oral use. Inulin is recommended sometimes for diabetics; it has a mildly sweet taste, and is filling like starchy foods, but because it is not absorbed, it does not affect blood sugar levels. Despite the similarity of its name to insulin, inulin has no connection with that hormone either chemically or through physiological activity. Inulin is soluble in hot water, but only slightly soluble in cold water or alcohol, so is not present to any significant extent in tinctures. All the above herbs have traditionally been taken in decoctions, and in this form may deliver significant amounts of inulin.
Recent research has shown an important physiological action for inulin (Gibson, Roberfroid). Like some pectins and fructooligosaccharides, inulin is a preferred food for the lactobacilli in the intestine and can improve the balance of friendly bacteria in the bowel. Subjects in one trial were give 15 grams of inulin a day for fifteen days. Lactobacillus bifidobacteria increased by about 10% during that period. Gram-positive bacteria associated with disease declined. Bifidobacteria digest inulin to produce short chain fatty-acids, such as acetic, propionic, and butyric acids. The first two may be used by the liver for energy production, while butyric acid has cancer-preventing properties within the intestine (Spiller, 1994). Recent animal research also shows that inulin prevents precancerous changes in the colon (Reddy, 1997).
Table 1 shows the plants with the highest inulin content listed on the U.S. Department of Agriculture phytochemical database. Each of these plants, with the exception of Echinacea, have been used in ethnomedicine to improve intestinal health. Echinacea has not been traditionally consumed as a decoction or eaten in food quantities, and thus the amount of inulin ingested would not be significant. It would not necessarily be desirable to prepare it as a tea, because key immune-stimulating constituents are only soluble in alcohol. Saussurea is commonly used in traditional Chinese medicine as a "spleen tonic" or digestive tonic. In some regions of China, Inula helenium <D>is freely substituted for saussurea (Hsu). Note that elecampane, although pigeonholed by modern North American herbalists as a lung tonic, was used by the Eclectics both as a lung and digestive tonic (Felter). Another common Chinese digestive and "spleen" tonic that contains inulin is codonopsis, an ubiquitous ginseng substitute in contemporary traditional Chinese medicine.
Felter, H.W. The Eclectic Materia Medica, Pharmacognosy, and Therapeutics. Portland, Oregon: Eclectic Medical Publications, (reprint from 1922 original)
Gibson GR; Beatty ER; Wang X; Cummings JH. Selective stimulation of bifidobacteria in the human colon by oligofructose and inulin. Gastroenterology,<D> 1995 Apr, 108:4, 975-82
Reddy BS, Hamid R, Rao CV Effect of dietary oligofructose and inulin on colonic preneoplastic aberrant crypt foci inhibition. Carcinogenesis<D> 1997 Jul;18(7):1371-1374
Hsu, Hong-yen. Oriental Materia Medica: A Concise Guide. Long Beach, California: Oriental Healing Arts Institute, 1986
Roberfroid M. Dietary fiber, inulin, and oligofructose: a review comparing their physiological effects. Crit Rev Food Sci <D>1993,33(2):103-48
Spiller, GA. Dietary Fiber in Health and Nutrition.<D> Boca Raton, Florida: CRC Press, 1994
Wang X, Gibson GR. Effects of the in vitro fermentation of oligofructose and inulin by bacteria growing in the human large intestine. J Appl Bacteriol<D> 1993 Oct;75(4):373-380
Copyright 1997 by Paul Bergner. All right reserved