The seeds of milk thistle, or Silybum marianum, have been used to treat liver disorders for almost two millennia, according to a 2007 review in "Integrative Cancer Therapies." Although milk thistle is not approved in the U.S. for treating any medical condition, researchers have examined the plant's effects in a variety of illnesses, including hepatitis C, cancer, HIV and diabetes. A 2002 review in "The American Journal of Medicine" reports that milk thistle is the most frequently used dietary supplement by people with chronic liver disease. Consult your doctor before taking milk thistle.
Chronic Liver Disease
In 2007, "Cochrane Database of Systematic Reviews" reported that alcohol and viral infections, such as hepatitis B and C, cause the majority of chronic liver diseases. However, in 2005, experts at the Mayo Clinic in Rochester, MN, stated that nonalcoholic fatty liver disease, a condition associated with obesity and diabetes, is becoming the most common chronic liver condition in the Western world, and it is already the most common cause of elevated liver enzymes in the U.S.
Milk Thistle Constituents
Silymarin, the principal extract from milk thistle seeds, is a mixture of flavonoid-like molecules that exhibit anti-inflammatory, antioxidant and anticancer properties. Flavonoids and their relatives are attributed with the presumed health benefits of a variety of foods and herbs, such as green tea, citrus fruit and dark chocolate. Among the flavonoids found in silymarin, silibinin is probably the most important.
Silibinin Preparations Differ in Effectiveness
Reviews from "The American Journal of Medicine" and the Cochrane Database concluded that orally-administered milk thistle did not change the course of chronic liver disease. However, both reviews conceded that more research is needed before final conclusions can be drawn. Interestingly, a 2008 study in "Gastroenterology" demonstrated that intravenous silibinin exerted a potent antiviral effect in patients with hepatitis C who were not responding to conventional therapy. A 2011 "PLoS One" trial reiterated the differences between intravenous and oral preparations of silibinin.
Considerations
Milk thistle has been used to treat liver disorders for generations. Despite its popularity, consistent scientific evidence of clinical benefit from milk thistle is lacking. There appears to be a difference in efficacy between intravenous and oral formulations. Oral preparations might not provide high enough levels of silibinin to confer measurable benefits. Milk thistle does not appear to exhibit significant toxicity, but close scrutiny of its safety profile or its potential interactions with medications has not been undertaken to date. If you have liver problems and want to try milk thistle, talk to your physician first.
References
- "Integrative Cancer Therapies"; Review of Clinical Trials Evaluating Safety and Efficacy of Milk Thistle (Silybum marianum [L.] Gaertn.); C. Tamayo, S. Diamond; June 2007
- "The American Journal of Medicine"; Milk Thistle for the Treatment of Liver Disease: A Systematic Review and Meta-Analysis; B.P. Jacobs et al; October 2002
- "Cochrane Database of Systematic Reviews"; Milk Thistle for Alcoholic and/or hepatitis B or C virus liver diseases; A. Rambaldi et al; October 2007
- "Canadian Medical Association Journal"; Nonalcoholic Fatty Liver Disease; L. Adams et al; March 2005
- "Gastroenterology"; Silibinin Is a Potent Antiviral Agent in Patients With Chronic HCV not Responding to Pegylated Interferon/Ribavirin Therapy; P. Ferenci et al; August 2008
- "PLoS"; Differential In Vitro Effects of Intravenous versus Oral Formulations of Silibinin on the HCV Life Cycle and Inflammation; J. Wagner et al; January 2011
