Some Milk Thistle or Licorice Root for Your Liver?

From the WebMD Archives

Nov. 16, 1999 (Bethesda, Md.) - As evinced by the turnout at a recentNational Institutes of Health conference examining alternative ornontraditional medicine treatments for liver disease -- and reports fromresearchers from around the world -- herbal therapies are a runaway successwith consumers who are desperate to find a remedy. The problem is thatscientists don?t know enough yet to say whether the increasingly popular herbaltreatments -- such as milk thistle and licorice root -- actually work, orhow.

According to survey findings presented at the meeting, more than 40% ofpatients at liver disease clinics were also using such alternative remedies."There's a need for physicians to be aware of the fact that people areusing these medicines, [and] for patients to be aware that they should telltheir physicians," Bruce Bacon, MD, tells WebMD. Bacon, a professor ofinternal medicine at St. Louis University School of Medicine and an organizerof the meeting, adds, "There really isn't all that much known about whetheror not what they're taking is effective or potentially harmful."

Conventional treatment of liver disease "is frequently difficult andfrustrating," Bacon says, and effective therapies have only emerged in thepast 10 years. Alcoholism-related liver disease, for example, is the leadingcause of cirrhosis and liver-related deaths, but no therapy for it has beenapproved by the FDA.

Hepatitis patients have also taken a strong interest in alternativetherapies. More than 2% of the U.S. population is estimated to have hepatitisC, a leading cause of liver disease and the chief reason for liver transplants.But the viral disease has no cure, and standard therapy is effective in only asmall percentage of patients.

While several herbs and herbal preparations appear promising, clinical dataconcerning their roles in treating liver disease are relatively scanty. It isknown, however, that some herbs are strongly toxic to the liver.

Milk thistle (silymarin), a commonly used alternative medication for liverproblems, is well established as liver-protective, says Peter Ferenci, MD, aprofessor of medicine at the University of Vienna, Austria. As a treatment forliver disease, however, he says that its "clinical benefits ... aredifficult to establish." Ferenci pointed out that no one has conductedscientifically sound trials using the milk thistle in patients who havedeveloped acute liver disease from drugs, environmental toxins or ethanol ormushroom poisoning.

A licorice root extract called glycyrrhizin has also shown promise as apossible remedy for chronic hepatitis C and liver cancer, says University ofCalifornia, Davis, researcher Mark Zern, MD. But how it works is unclear, Zernsays, and its long-term benefits have not been tested.

Commenting on both therapies, Bacon tells WebMD, "Those are relativelyharmless medicines, but there's very little data showing that they're[effective]."

There are other herbal preparations that may help livers heal. Baconpresented findings on a 10-herb mixture that showed an effect on rat cells, butthe potential therapeutic mechanism -- and the effect of the mixture in humans-- are unknown. And Japanese researcher Hidetsugu Saito, MD, presented findingson a group of herbal mixtures, known as Hozai, that appears to have anti-cancereffects.

Although solid scientific research is needed to establish the benefits andrisks of herbal products as liver treatments, the FDA's weak regulation ofdietary supplements isn't going to drive companies to conduct the studies,Bacon says. "I don't think there's an incentive [for] the industries thatmake these things, because they're already out on the market."

The event was organized by the National Institute of Diabetes and Digestiveand Kidney Diseases, along with NIH's National Center for Complementary andAlternative Medicine, its Office of Dietary Supplements, and the AmericanAssociation of Naturopathic Physicians.