Almost a third of the estimated 3.2 million Americans with hepatitis C, as well as millions around the world, take silymarin, an extract of milk thistle, with the hope of alleviating their symptoms and preventing disease progression. The supplement is alleged to have anti-inflammatory, antioxidant, and antiviral properties. However, a new, small study from the University of North Carolina School of Medicine has found that taking silymarin will not, in fact, help to treat hepatitis C.
The study, published in JAMA, recruited 154 people with chronic hepatitis C, who were then divided into three groups. Two-thirds of participants received either 420 mg of silymarin or 720 mg three times daily, while one-third received only a placebo. The supplement administered was of high quality, according to the authors.
Yet the silymarin appeared to have no effect. After 24 weeks, researchers found no significant difference in the liver enzyme levels or levels of hepatitis C virus in any of the study groups.
Because silymarin is so widely used, the results of this study are particularly important. However, the findings should be cautiously interpreted.
While these results are noteworthy, said ACSH s Dr. Gilbert Ross, it s important to take note of the size of the study, which examined only 154 people. One cannot generalize these findings on the basis of such a small sample size. As our Dispatch readers know, ACSH is no fan of supplements, but we must adhere to scientific methods when evaluating the generalizability of clinical studies. This one is too small to make definitive statements about milk thistle.
However, ACSH s Dr. Ruth Kava observes that, although this study was too small to enable us to generalize, it does fit with a larger body of research that has demonstrated the lack of efficacy of a number of so-called dietary supplements.