Nov. 16, 1999 (Bethesda, Md.) - As evinced by the turnout at a recent National Institutes of Health conference examining alternative or nontraditional medicine treatments for liver disease -- and reports from researchers from around the world -- herbal therapies are a runaway success with consumers who are desperate to find a remedy. The problem is that scientists don?t know enough yet to say whether the increasingly popular herbal treatments -- such as milk thistle and licorice root -- actually work, or how.
According to survey findings presented at the meeting, more than 40% of patients at liver disease clinics were also using such alternative remedies. "There's a need for physicians to be aware of the fact that people are using these medicines, [and] for patients to be aware that they should tell their physicians," Bruce Bacon, MD, tells WebMD. Bacon, a professor of internal medicine at St. Louis University School of Medicine and an organizer of the meeting, adds, "There really isn't all that much known about whether or not what they're taking is effective or potentially harmful."
Conventional treatment of liver disease "is frequently difficult and frustrating," Bacon says, and effective therapies have only emerged in the past 10 years. Alcoholism-related liver disease, for example, is the leading cause of cirrhosis and liver-related deaths, but no therapy for it has been approved by the FDA.
Hepatitis patients have also taken a strong interest in alternative therapies. More than 2% of the U.S. population is estimated to have hepatitis C, 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 a small percentage of patients.
While several herbs and herbal preparations appear promising, clinical data concerning their roles in treating liver disease are relatively scanty. It is known, however, that some herbs are strongly toxic to the liver.
Milk thistle (silymarin), a commonly used alternative medication for liver problems, is well established as liver-protective, says Peter Ferenci, MD, a professor of medicine at the University of Vienna, Austria. As a treatment for liver disease, however, he says that its "clinical benefits ... are difficult to establish." Ferenci pointed out that no one has conducted scientifically sound trials using the milk thistle in patients who have developed acute liver disease from drugs, environmental toxins or ethanol or mushroom poisoning.
A licorice root extract called glycyrrhizin has also shown promise as a possible remedy for chronic hepatitis C and liver cancer, says University of California, Davis, researcher Mark Zern, MD. But how it works is unclear, Zern says, and its long-term benefits have not been tested.
Commenting on both therapies, Bacon tells WebMD, "Those are relatively harmless medicines, but there's very little data showing that they're [effective]."
There are other herbal preparations that may help livers heal. Bacon presented findings on a 10-herb mixture that showed an effect on rat cells, but the potential therapeutic mechanism -- and the effect of the mixture in humans -- are unknown. And Japanese researcher Hidetsugu Saito, MD, presented findings on a group of herbal mixtures, known as Hozai, that appears to have anti-cancer effects.
Although solid scientific research is needed to establish the benefits and risks of herbal products as liver treatments, the FDA's weak regulation of dietary supplements isn't going to drive companies to conduct the studies, Bacon says. "I don't think there's an incentive [for] the industries that make these things, because they're already out on the market."
The event was organized by the National Institute of Diabetes and Digestive and Kidney Diseases, along with NIH's National Center for Complementary and Alternative Medicine, its Office of Dietary Supplements, and the American Association of Naturopathic Physicians.