Milk thistle ( Silybum marianum ) has been used since ancient times as an herbal remedy for a numberof ailments, particularly liver problems.

By the late 19th and early 20th centuries,  physicians in the United States began using milk thistle seeds to relieve congestion of the liver, spleen, and kidneys.

Today, numerous studies suggest that active substances in milk thistle (particularly silymarin) protect the liver from damage caused by viruses, toxins, alcohol, and certain drugs such as acetaminophen. 

Mushroom Poisoning

Milk thistle has also been used as a preventive and/or antidote to poisoning by deathcap mushroom (Amanita phalloides). Animal studies have found that milk thistle extract completely counteracts the toxic effects of the mushroom when given within 10 minutes of ingestion. If given within 24 hours of ingestion, the herb significantly reduces the risk of liver damage and death.

Liver disease from alcohol

A comprehensive review by the U.S. Agency for Healthcare Research and Quality (AHRQ) recently identified 16 scientific studies on the use of milk thistle for the treatment of various forms of liver disease. A European standardized extract of milk thistle was used in most of the trials.

Five of seven studies evaluating milk thistle for alcoholic liver disease found significant improvements in liver function. Those with the mildest form of the disease appeared to improve the most. Milk thistle was less effective for those with severe liver disease such as cirrhosis. Cirrhosis is characterized by scarring and permanent, non-reversible damage to the liver. It is often referred to as end-stage liver disease.

Cancer

Preliminary studies suggest that active substances in milk thistle may have anti-cancer effects. One active substance known as silymarin has strong antioxidant properties and has been shown to inhibit the growth of human prostate, breast, and cervical cancer cells in test tubes.

References

Agency for Healthcare Research and Quality. Milk thistle: effects on liver disease and cirrhosis and clinical adverse effects. Summary, evidence report/technology assessment: number 21, September 2000. Accessed at: http://www.ahrq.gov/clinic/milktsum.htm on April 15, 2002. Bhatia N, Zhao J, Wolf DM, Agarwal R. Inhibition of human carcinoma cell growth and DNA synthesis by silibinin, an active constituent of milk thistle: comparison with silymarin. Cancer Lett . 1999;147(1-2):77-84. Blumenthal M, Goldberg A, Brinckmann J. Herbal Medicine: Expanded Commission E Monographs . Newton, MA: Integrative Medicine Communications; 2000:257-263. Bokemeyer C, Fels LM, DunnT, et al. Silibinin protects against cisplatin-induced nephrotoxicity without compromising cisplatin on isosfamide anti-tumor activity. Br J Cancer . 1996;74:2036–2041. Brinker F. Herb Contraindications and Drug Interactions . 2nd ed. Sandy, OR: Eclectic Medical Publications; 1998:103-104. Campos R, Garrido A, Guerra R, et al. Silybin dihemisuccinate protects against glutathione depletion and lipid peroxidation induced by acetaminophen on rat liver. Planta Med . 1989;55:417–419. Feher J, Deak G, Muzes G, Lang I, Neiderland V, Nekan K, et al. Hepatoprotective activity of silymarin therapy in patients with chronic alcoholic liver disease. Orv Hetil . 1990;130:51. Ferenci P, Dragosics B, Dittrich H, Frank H., Benda L, Lochs H, et al. Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver. J Hepatol . 1989;9:105-113. Fintelmann V. Modern phytotherapy and its uses in gastrointestinal conditions. [Review]. Planta Med. 1991;57(7):S48-52.Flora K, Hahn M, Rosen H, Benner K. Milk thistle ( Silybum marianum ) for the therapy of liver disease. Am J Gastroenterol . 1998;93:139–43.Gaedeke J, Fels LM, Bokemeyer C, et al. Cisplatin nephrotoxicity and protection by silibinin. Nephrol Dial Transplant . 1996;11:55–62. Giese LA. A study of alternative health care use for gastrointestinal disorde