Milk Thistle Information Page

Copyright© 1995 by The Herb Quarterly. All rights reserved.
The following is an excerpt of an article that appeared in the summer 1995. The Herb Quarterly Reprinted by permission.

Milk Thistle:
Nature's Liver Protector

By Michael Castleman

Mainstream medicine has little to offer those with disease of the liver. "Most liver treatment," says herbal medicine authority Varro Tyler, Ph.D., the Lily distinguished professor of pharmacognosy (natural product medicine) at Purdue University, is simply supportive." Doctors keep patients comfortable and away from liver-damaging drugs, alcohol, and viruses until the organ can heal itself (if it can).

However, liver healing could be significantly spurred by a remarkable herb that has been hiding in plain sight for almost 2,000 years. It's milk thistle (Silybum marianum). This common herb's value against liver disease has been demonstrated in more than 100 rigorous scientific experiments. Unfortunately, the vast majority of these studies have been European, mostly German, and few mainstream American physicians read German botanical medicine journals. As a result, they are in the dark about milk thistle's astonishing liver-protective powers.

Mary's Milk

Milk thistle is native to the Kashmir region of India and Pakistan, but now grows throughout the temperate world. The plant grows from five to ten feet tall, and has large prickly leaves and reddish purple flowers with sharp spines that resemble artichokes. When de-spined, milk thistle leaves are edible, and some vegetable gardeners cultivate the plant as a substitute for spinach. When broken or crushed, the stems and leaves exude a milky white juice, hence this herbs's name. Milk thistle's specific name, marianum, comes from an ancient legend that its leaf veins turned white after being touched by a drop of the Virgin Mary's breast milk.

Milk thistle has been used in traditional herbal medicine since the first century, when the Roman naturalist, Pliny the Elder (AD. 23-79), wrote that the plant's milky juice was good for "carrying off bile." (Today "bile" denotes a product of the gall bladder, part of the liver, which assists in the digestion of fats, but in ancient times, bile was used more generally to describe any internal fluid.) The noted 16th century British herbalist, John Gerard, was the first to recommend milk thistle for liver problems, though his prescription was oblique. He actually suggested the herb for "expelling melancholy," which physicians at the time considered a liver ailment. Half a century later, Britain's most famous herbalist, Nicholas Culpepper, was the first to recommend milk thistle specifically for liver disorders. By the 19th century, German physicians were using a tincture prepared from milk thistle seeds (actually the plants seed like fruits) to treat jaundice and other liver diseases. America's 19th century eclectic physicians, who specialized in botanical medicines, adopted the herb for liver ailments and for intestinal cleansing.

With the rise of the modem pharmaceutical industry, U.S. research of herbal medicines declined considerably. Fortunately, this did not happen in Germany, where in 1949, scientists noticed that milk thistle seemed to protect animal livers from poisoning with highly toxic carbon tetrachloride. In 1968, scientists isolated the three specific liver-protective molecules in milk thistle - silibinin, silidianin, and silicristin - now known collectively as silymarin [ milk thistle extract ].

Studies Galore

More than 100 studies have confirmed silymarin's [ milk thistle extract ] liver-protective value. Here is a brief overview of what researches have discovered:

* Alcoholic Cirrhosis. A 1989 report in the Journal of Hepatology (study of the liver) described a study involving 170 people with advanced alcoholic cirrhosis, an often fatal condition, and the nation's 11th leading cause of death, claiming 25,000 lives each year. The study participants were divided into two groups. One received 200 mg of milk thistle extract (140 mg of silymarin [ milk thistle extract ]) three times a day, the other received a medically inactive look-alike placebo. Both groups were followed for four years. During that time, the death rate in the placebo group was about 60 percent, but among those taking silymarin [ milk thistle extract ], only 40 percent died, a highly statistically significant difference. Other studies have shown that silymarin [ milk thistle extract ] provides similar benefits for people suffering from cirrhosis.

* Death cap mushroom poisoning. The common wild mushroom, Amanita phalloides, is known as the "death cap" for a good reason. It takes only a handful of this widely distributed fungus to kill an adult, less to kill a child. Standard medical treatment - activated charcoal - is not particularly effective. Amanita mushroom ingestion proves fatal in about half of the cases. Twenty years ago, pilot studies showed that silymarin [ milk thistle extract ] treatment substantially reduced amanita-poisoning deaths in animals fed the mushroom. Subsequently, several human studies were launched. In one German hospital test, 60 consecutive people with amanita poisoning were given intravenous silymarin [ milk thistle extract ]. None died. Other studies have produced results that are similar, though not as spectacular. (However, the success of silymarin [ milk thistle extract ] in treating amanita poisoning should not encourage anyone to go mushroom hunting without training in amanita avoidance. Unless your an experienced hunter, the only place to pick mushrooms is at a produce market.)

* Hepatitis. Hepatitis means liver inflammation. It is not one disease, but several, most of which are caused by different viruses that attack liver cells. The three most common forms are hepatitis A, B, and C. Hepatitis A is food borne. Hepatitis B and C are blood borne and sexually transmitted. Mainstream medicine treats all forms of hepatitis with rest and avoidance of alcohol and other drugs and toxins that tax the liver.

However, silymarin [ milk thistle extract ] is a more effective approach. In one study, 77 people with hepatitis were divided into to groups, one treated with silymarin [ milk thistle extract ], the other with a placebo. Average recovery time for the placebo-takers was 43 days, but those who took silymarin [ milk thistle extract ] recovered in an average of just 29 days.

* Gallstones. Up to 10 percent of Americans are estimated to have gallstones, little pebbles that develop in the gallbladder. Some cause no symptoms, but many cause abdominal pain, sometimes severe enough to require surgical removal of the gallbladder. Most gallstones are formed from cholesterol, and then precipitates out as stones. A low-fat, low-cholesterol diet helps prevent gallstones. So does silymarin [ milk thistle extract ]. In one study, people with gallstones were given 420 mg of silymarin [ milk thistle extract ] a day. Without diet changes, after several weeks, they showed significant reductions in the cholesterol concentration of their bile, which minimized the risk of stone formation.

* Liver Function Tests. The liver metabolizes all drugs, and powerful medications often stress the liver, producing abnormal liver function tests that sometimes require physicians to stop drug treatment people need. Silymarin [ milk thistle extract ] helps normalize liver function, allowing those who must take liver-harming medications to do so with less risk of liver damage. In one study, 66 women taking anticonvulsant or psychiatric medications showed abnormal liver-function tests. They began taking silymarin [ milk thistle extract ] in addition to their medication, and 52 of them showed significant improvements in liver function.

* Occupational Toxic Chemical Exposure. Like drugs, toxic chemicals also stress the liver, causing liver-function tests to register abnormal results. European studies show that silymarin [ milk thistle extract ] renormalizes liver-function tests in workers who produce pesticides, and in those exposed to toxic heavy metals, for example, lead and cadmium.

* Psoriasis. A few European studies suggest that silymarin [ milk thistle extract ] may even help treat the scaly skin patches of psoriasis.

How Silymarin [ milk thistle extract ] works

Silymarin [ milk thistle extract ] works in three ways. It strengthens the outer membranes of liver cells, preventing penetration by liver-damaging substances. This accounts for its effectiveness against amanita mushroom poisoning. Both silymarin [ milk thistle extract ] and the mushroom toxins bind to the same sites on liver cell membranes. As silymarin [ milk thistle extract ] blood levels increase, the milk thistle extract occupies the cell-membrane receptor sites, displacing the amanita toxins.

Silymarin [ milk thistle extract ] also protects liver cells because of its powerful antioxidant action. Antioxidants neutralize cell damage caused by chemically unstable oxygen molecules formed by high-fat diets, smoking, and other toxic substances. The best known antioxidants are Vitamin A (beta-carotene), Vitamin C, Vitamin E, and the mineral selenium. However, in the liver, silymarin [ milk thistle extract ] is more than 10 times as potent an antioxidant as Vitamin E.

Finally, silymarin [ milk thistle extract ] inhibits the action of the enzyme largely responsible for inflammation in hepatitis.

As far as scientists know, silymarin [ milk thistle extract ] does not interfere with the liver's metabolism of drugs, so it does not interfere with the action of medications.

Preventive Medicine?

You don't have to munch amanita mushrooms to stress your liver. Every day we're exposed to pollutants, pesticides, food additives, and other substances that the liver must detoxify. In addition, anyone who drinks alcohol or takes any medication - either prescription or over-the-counter drugs - boosts the liver's workload, and damages some liver cells in the process. Fortunately for all of us, the liver is quite large. Its the second largest organ, after the skin, so you can lose millions of liver cells and still function normally. But why lose even a single liver cell if you don't have to?

Recently, Scandinavian researchers tested silymarin's [ milk thistle extract ] effect on livers that were stressed but not seriously diseased. They selected 106 consecutive patients who had abnormal liver-function tests from alcohol use, but who did not have cirrhosis. Half took silymarin [ milk thistle extract ]: the other half received a placebo. After four weeks, the placebo group showed no change in liver-function, but the silymarin [ milk thistle extract ] group showed highly significant improvement, in some cases, complete normalization of liver-function, despite their alcohol consumption. Perhaps we all should take silymarin [ milk thistle extract ]. Robert McCaleb, president of the Herb Research Foundation in Longmont, Co., does: "If I worked in an occupation [that stressed the liver], I would take milk thistle regularly, once each workday morning. [but I don't, so] I take two tablets before working with paints or solvents, and I never take aspirin acetaminophen (tylenol) without also taking milk thistle. Finally, I always take milk thistle along when traveling because almost invariably I find myself at a cocktail party" (Sage Counsel).

The Herb Quarterly is a recommended publication for anyone with an interest in herbs. Articles such as this, as well as articles on Essiac and the Hoxsey formula have all appeared in the magazine. For subscription information call 800-371-HERB (4372) or write:

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