Nutritional Supplement

Oak

Also indexed as: Quercus spp.

Parts Used & Where Grown

Oak trees grow throughout North America. Some species of oak grow around the world, including in China and the Middle East. The bark of the oak tree is used medicinally.

How It Works

Tannins are the primary constituents of oak bark.1 These tannins are potent astringents, akin to those found in witch hazel (Hamamelis virginiana). Tannins bind liquids, absorb toxins, and soothe inflamed tissues. The oak tannin, known as ellagitannin, inhibits intestinal secretion,2 which helps resolve diarrhea. The nonirritating, astringent nature of oak has led to its recommendation for treating mild, acute diarrhea in children (along with plenty of electrolyte-containing fluids) in Europe.3 Astringents such as oak may also help relieve the pain of sore throats and canker sores.

References

1. Weiss RF. Herbal Medicine. Beaconsfield, UK: Beaconsfield Publishers Ltd., 1988, 328-9.

2. Konig M, Scholz E, Hartmann R, et al. Ellagitannins and complex tannins from Quercus petraea bark. J Nat Prod 1994;57:1411-5.

3. Schilcher H. Phytotherapy in Paediatrics. Stuttgart, Germany: Medpharm Scientific Publishers, 1997, 49-50.

4. Weiss RF. Herbal Medicine. Gothenberg, Sweden: Ab Arcanum and Beaconsfield: Beaconsfield Publishers Ltd, 1988, 328-9.

5. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 168-70.

6. Ellingwood F. American Materia Medica, Therapeutics and Pharmacognosy. Sandy, OR: Eclectic Medical Publications, 1919, 1998, 354.

7. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 168-70.

8. Ellingwood F. American Materia Medica, Therapeutics and Pharmacognosy. Sandy, OR: Eclectic Medical Publications, 1919, 1998, 354.

9. Plein K, Burkard G, Hotz J. Treatment of chronic diarrhea in Crohn disease. A pilot study of the clinical effect of tannin albuminate and ethacridine lactate. Fortschr Med 1993;111:114-8 [in German].

10. Konig M, Scholz E, Hartmann R, et al. Ellagitannins and complex tannins from Quercus petraea bark. J Nat Prod 1994;57:1411-5.

11. Schilcher H. Phytotherapy in Paediatrics. Stuttgart, Germany: Medpharm Scientific Publishers, 1997, 49-50.

12. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 485-7.

13. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 175-6.

14. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 175-6.

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.