A 2007 review in "Integrative Cancer Therapies" reports that milk thistle, or Silybum marianum, has been revered for its liver-protective properties for two millennia, and it may be useful for helping to prevent diabetes, cancer and heart disease, as well. Although it has not been approved in the United States for treating or preventing any condition, milk thistle remains a popular dietary supplement among people who suffer from any number of liver disorders.
Milk Thistle Basics
Milk thistle, which is also known as holy thistle or Mary thistle, is native to the Mediterranean region. The herb's dried seeds are the source of milk thistle's medicinal properties, which, according to "Physicians' Desk Reference for Herbal Medicines," are a group of flavonolignans collectively known as sylimarin. The National Center for Complementary and Alternative Medicine reports that the most important constituent of silymarin is a compound known as silybinin or sylibin.
Protection From Toxins
Dr. Michael Tierra, author of "The Way of Herbs," states that milk thistle has "conclusively" been shown to protect the liver from the toxic effects of the deadly Amanita phalloides mushroom. A 2005 "American Family Physician" review corroborates the benefits of intravenous silybinin in treating Amanita poisoning, but intravenous silybinin is not available in the United States. Silybinin has also shown to protect the liver from other hepatotoxins, such as carbon tetrachloride, alcohol and xylene. Milk thistle is not approved in the U.S. for use in any medical condition.
Protection From Viruses
Milk thistle is often used by individuals who suffer from chronic infectious hepatitis, such as that caused by the hepatitis B and C viruses. According to "American Family Physician," clinical trials evaluating the effects of silybinin on viral hepatitis have produced conflicting results. These trials have, in the main, been poorly designed, and no effort was made to standardize milk thistle preparations. However, a 2010 "Hepatology" study demonstrated that silymarin inhibited hepatitis C infection by interfering with viral transmission and viral entry into liver cells. Milk thistle is not approved in the U.S. for treating infectious hepatitis.
Considerations and Recommendations
Although not approved for use in the United States, milk thistle appears to confer protective effects on the human liver. Studies show benefits in both toxic and infectious exposures. Most clinical studies involving oral milk thistle preparations used doses ranging from 420 to 480 mg daily, divided in two or three doses. If you think milk thistle would be beneficial for you, talk with your physician.
References
- "Integrative Cancer Therapies"; Review of Clinical Trials Evaluating Safety and Efficacy of Milk Thistle; C. Tamayo; June 2007
- "Physicians' Desk Reference for Herbal Medicines: Milk Thistle"; Thomas Fleming, Pharm.D., Chief Editor; 2000
- National Center for Complementary and Alternative Medicine: Milk Thistle
- "The Way of Herbs: Milk Thistle"; Michael Tierra, L.Ac., OMD; 1998
- "American Family Physician"; Milk Thistle; F. Rainone; October 2005
- "Hepatology"; Multiple Effects of Silymarin on the Hepatitis C Virus Life Cycle; J. Wagoner, et al.; June 2010
