Dr. Andrea Rambaldi, visiting researcher at the Centre for Clinical Intervention Research at Copenhagen University Hospital, led a team that reviewed 13 randomized clinical trials involving 915 patients who were treated with milk thistle or its extracts.
They concluded that while some studies suggested that liver-related mortality may be reduced in patients treated with milk thistle, these findings were not duplicated in higher quality clinical trials.
The participants concerned had acute or chronic alcoholic liver cirrhosis, liver fibrosis, hepatitis and/or steatosis, and viral-induced liver disease (hepatitis B and/or hepatitis C). And the trials compared the efficacy of milk thistle or any milk thistle constituent versus placebo or no intervention in patients with liver disease.
"There is no evidence supporting or refuting milk thistle for alcoholic and/or hepatitis B or C virus liver diseases," said the authors in the most recent issue of The Cochrane Library that evaluates medical research.
According to the Centers for Disease Control and Prevention, 170 million people worldwide are infected with hepatitis C, and 2 billion are infected with hepatitis B. While a vaccine exists to prevent hepatitis B, there is no vaccine for hepatitis C. Moreover, a lack of effective treatment for liver disease means researchers have looked for alternative therapies that curb symptoms with minimum adverse effects on patients, such as milk thistle and its extracts.
Hence, Rambaldi and colleagues concluded that "large-scale randomized clinical trials on milk thistle for alcoholic and/or hepatitis B or C liver diseases versus placebo may be needed" trials to see whether there genuinally is any science in the link between milk thistle and alcoholic and/or hepatitis B or C virus liver diseases.
Meanwhile, milk thistle was found safe to us with no serious side effects and with participants perceiving improvement in symptoms - although no more than with placebo.