Date: Fri, 11 Aug 2000 07:16:40 -0700

FINDINGS OF FACT

By Christopher Wanjek

Special to The Washington Post

Tuesday , August 8, 2000 ; Z08

Several dietary supplements and herbal remedies claim to clean out and improve the function of the liver. It seems reasonable enough: Since the liver helps "clean" the blood and carries out other vital functions, spiffing up the liver should improve your overall health. Right?

Well, not necessarily. There are really two questions involved.

The first is whether an herbal or supplement can help the liver do its job better. Those who claim the answer is yes can cite research that is suggestive but not conclusive. Many studies of individual ingredients, in animals and humans, show that they can have some benefit to diseased livers. But there is no gold-standard scientific testing to demonstrate the benefits of most liver "formulas" being sold directly to consumers.

And as for the second question--whether a product can "detoxify" or "cleanse" the liver--those who say yes are on much shakier ground.

"I'm not sure if there is such a process," says Adrian Di Bisceglie, medical director of the American Liver Foundation. To him, the "detoxification claims" make no sense. "Toxins don't accumulate in the liver. They are circulated in the body."

The potential for confusion lies in the fact that the liver itself detoxifies the blood. Everything you swallow that is broken down and absorbed into the bloodstream passes through the liver. The body depends on the liver to regulate, synthesize, store and secrete many important proteins and nutrients and to purify, transform and clear toxic or unneeded substances.

Detoxification is the process of turning potentially harmful chemicals (deriving from alcohol, medicines or even food) into water-soluble chemicals that can be excreted. Those toxins that do get past the liver ultimately pass through it again. They may be completely or partially detoxified, but they do not stay in the liver.

In other words, though the liver helps detoxify the blood, the organ does not function like some sort of lint screen that becomes saturated with intercepted toxins needing to be shaken loose. Di Bisceglie said that vitamin A can, if ingested in large amounts, accumulate in the liver and cause problems. Iron and copper can accumulate there due to rare genetic conditions. But that's about it.

Some product names and marketing slogans appear to invite confusion about whether the liver needs to be cleaned. A company named Yerba Prima makes "Liver Support and Cleanse Formula"; Nature's Answer makes "Liver Cleanse and Herbal Extract"; and Liverite Products Inc. markets Liverite, "the ultimate liver aid; the key to cleanse and detoxify."

Liverite, a combination of vitamin B12, amino acids and other active ingredients, is advertised on local radio and sold in many major drugstore chains. In its radio commercials and on its Web site, the pill's makers, based in Tustin, Calif., recommend using the dietary supplement "daily or when needed to detoxify and cleanse one's liver," particularly before and after drinking alcohol.

Corinne Jacobson, a spokeswoman for Liverite, explained that claim in a different way. The product "helps the liver cope" when over-stressed by toxins from medication and alcohol, she said. "Amino acids and other ingredients in our product have the capacity to reduce levels of acetaldehyde-induced toxicity brought on by alcohol consumption."

Whether or not it's possible to "detoxify" or "cleanse" the liver, a larger question remains: Can supplements and herbals otherwise help the liver perform better, perhaps mitigating the effects of alcohol abuse or excessive medication?

On this, the jury is still out. Many researchers accept that antioxidants, like those found in some herbals and dietary supplements, can help the body's cells fight off damage, remain healthy and perform better. But questions about proper doses and combinations of nutrients--and whether their effects can target specific organs and functions--remain unresolved.

"We cannot recommend these [liver products] without evidence, but on the other hand we cannot say that they have no value," said Keith Lindor, chair of gastroenterology and hepatology at the Mayo Clinic outside Minneapolis. "The NIH has a new [office] on alternative medicine which we hope will support research to answer such questions."

Long-popular herbal liver remedies such as milk thistle and dandelion--although well regarded by many liver specialists and herbalists--lack gold-standard evidence (prospective, placebo-controlled, double-blind studies in humans) to support claims of benefiting the liver. Most evidence supporting their use derives from traditional use, clinical observations and anecdotal reports.

"Milk thistle is well accepted in Germany as an effective drug in treating death-cap mushroom poisoning," says Varro Tyler, professor emeritus of pharmacognosy and natural drug products at Purdue University. He said that the herb's active ingredient, silymarin, is nearly 100 percent effective in treating people who eat this common poisonous mushroom. Silymarin seems to work, Tyler said, referring to recent studies conducted in Germany, by protecting and restoring liver cell integrity.

The National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health, is sponsoring a two-year animal study on the use of herbal remedies in Vietnam and China for the liver. Reports have not been issued yet.

"There is something to this stuff," said Steven Herrine, a liver specialist at Thomas Jefferson University Hospital in Philadelphia. "There is enough anecdotal evidence, enough testimonial evidence and a smattering of scientific evidence" to justify clinical trials of herbals for the liver.

Liverite, which contains numerous antioxidants, cites as support several studies that describe the benefits not of Liverite specifically, but of certain components of the preparation (such as vitamin B12 and niacin) on diseased livers. Some were conducted on humans, some on baboons and other animals. Several were published in foreign journals.

The lead author of the baboon study is Charles Lieber, a physician and researcher in New York. Liverite makers recommended him as a contact to discuss the value of dietary supplements for the liver. But Lieber said he does not "know of any controlled studies" done specifically with Liverite to support its makers' claims.

Raymond Chung, medical director of the liver transplant program at Massachusetts General Hospital and a professor at Harvard Medical School, agreed that, as some liver products' advertising suggests, alcohol and certain medications, such as the cholesterol-lowering agents Lipitor and other so-called statin drugs, can cause some liver cell damage in some people. "But there is no proven means of modulating that kind of injury" via supplements, Chung said.

Chung said people should not view liver-supporting dietary supplements or herbals as "a license to continue to ingest harmful agents."

Liverite's Jacobson agreed that people should not abuse alcohol and said that Liverite was not intended to convince people they can indulge without consequences. "In an ideal world, no one needs dietary supplements," she said. "But we are not living in an ideal world."

To maintain a healthy liver, the American Liver Foundation promotes a diet rich in fruits and vegetables, plenty of water and daily exercise. "While no studies have been done specifically to address" the direct effects of diet on liver function, Chung said, "a well-balanced diet will contain antioxidant molecules that may help ameliorate the effects of toxic compounds."

But both Herrine and Chung cautioned against taking herbals and dietary supplements casually. Herrine said he hadn't heard reports of adverse reactions to milk thistle. But since dietary supplements are not tested for safety or effectiveness by the Food and Drug Administration, danger may lie with a proprietary blend whose ingredients are not disclosed. Consumers and physicians alike cannot know the percentages of the ingredients.

Certain liver preparations, like GNC's Ultra Liver dietary supplement, include a Supplement Facts label that discloses active ingredients in precise amounts. While tests of many supplements reveal a difference between what is promised on the label and what is in the pill, a label can at least inform users of what's supposed to be in the bottles.

Chung points to another possible concern. "These [herbals and supplements] should certainly not be taken by people with chronic liver disease," Chung said. "These patients should consult their physicians." Signs of an unhealthy liver include fatigue and yellow discoloration of the skin and eyes. Reviewing some of the ingredients in Liverite, Chung added, "Niacin in large doses may be hepatotoxic [damaging to liver]. B12 is oftentimes found in excess in patients with liver disease; in these cases, the liver may not need more B12."

Jacobson said there are no hidden dangers in Liverite's proprietary blend nor the components therein. She also said a study on Liverite's effectiveness is underway and will be completed in a few months. She declined to provide specifics about where and when the study will be completed or how it is structured.

Although the liver has a remarkable ability to regenerate itself, the money in your wallet does not. All of the liver support products are fairly expensive, even when compared to other dietary supplements. Milk thistle capsules from Solaray cost about $17 for a month's supply; dandelion root capsules from Nature's Way cost about $10 for an 11-day supply; GNC's Ultra Liver costs $22 for a two-month supply. Liverite costs about $18 for a 10-day supply.

The American Liver Foundation's advice: Before investing in a liver "cleansing" or "support" regimen, think twice--and consult with a medical professional.

Christopher Wanjek is a Washington writer specializing in health and science. 

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