Milk Thistle

The milk thistle plant commonly grows from 2 to 7 feet in height, with spiny leaves and reddish-purple, thistle-shaped flowers. It has also been called wild artichoke, holy thistle, and Mary thistle. Native to Europe, milk thistle has a long history of use as both a food and a medicine. At the turn of the twentieth century, English gardeners grew milk thistle to use its leaves like lettuce (after cutting off the spines), the stalks like asparagus, the roasted seeds like coffee, and the roots (soaked overnight) like oyster plant. The seeds and leaves of milk thistle were used for medicinal purposes as well, such as treating jaundice and increasing breast milk production. German researchers in the 1960s were sufficiently impressed with the history and clinical effectiveness of milk thistle to begin examining it for active constituents. In 1986, Germanys Commission E approved an oral extract of milk thistle standardized to 70% crude silymarin content as a treatment for liver disease.

Based on the extensive folk use of milk thistle in cases of jaundice, European medical researchers began to investigate its medicinal effects. It is now widely used to treat alcoholic hepatitis, alcoholic fatty liver, liver cirrhosis, liver poisoning, and viral hepatitis, as well as to protect the liver from the effects of liver-toxic medications. According to some (but not all) research evidence, treatment produces improvements in symptoms of chronic liver disease, such as nausea, weakness, loss of appetite, fatigue, and pain. Liver enzymes as measured by blood tests may improve, and if a liver biopsy is performed, there may be improvements on the cellular level. In addition, some studies have shown a reduction in death rate among those with serious liver disease. The active ingredients in milk thistle appear to be four substances known collectively as silymarin, of which the most potent is named silibinin. When injected intravenously, silibinin is one of the few known antidotes to poisoning by the deathcap mushroom, Amanita phalloides. Animal studies suggest that milk thistle extracts can also protect against many other poisonous substances, from toluene to the drug acetaminophen. One animal study suggests that milk thistle can also protect against fetal damage caused by alcohol. Silymarin appears to function by displacing toxins trying to bind to the liver as well as by causing the liver to regenerate more quickly. It may also scavenge free radicals and stabilize liver cell membranes. However, milk thistle is not effective in treating advanced liver cirrhosis, and only the intravenous form can counter mushroom poisoning. In Europe, milk thistle is often added as extra protection when patients are given medications known to cause liver problems. However, milk thistle does not seem to prevent the liver inflammation caused by the anti-Alzheimers drug Cognex (tacrine). Milk thistle is also used in a vague condition known as minor hepatic insufficiency, or sluggish liver. This term is mostly used by European physicians and American naturopathic practitioners—conventional physicians dont recognize it. Symptoms are supposed to include aching under the ribs, fatigue, unhealthy skin appearance, general malaise, constipation, premenstrual syndrome, chemical sensitivities, and allergies. Milk thistle may also offer some protection to the kidney. Intriguing evidence suggests that milk thistle might help prevent breast cancer. Milk thistle is sometimes recommended for gallstones and psoriasis, but there is little to no evidence as yet that it really works for these conditions.

There is considerable evidence from studies in animals that milk thistle can protect the liver from numerous toxins. However, human studies of people suffering from various liver diseases have yielded mixed results. Deathcap Poisoning In Amanita mushroom poisoning, silibinin appears to dramatically reduce death rates, which are typically from 30 to 50%, down to less than 10%. This mushroom destroys the liver if left untreated. In conditions like this one, it isnt ethical to perform double-blind studies. However, milk thistle seems to be so dramatically effective that its value is widely accepted. Chronic Viral Hepatitis Preliminary double-blind studies of people with chronic viral hepatitis have found that milk thistle can produce significant improvement in symptoms such as fatigue, reduced appetite, and abdominal discomfort, as well as results on blood tests for liver inflammation. Acute Viral Hepatitis A 21-day double-blind placebo-controlled study of 57 people with acute viral hepatitis found significant improvements in the group receiving milk thistle. A 35-day study of 151 individuals thought to have acute hepatitis found no benefit with milk thistle, but this study has been criticized for failing to document that the participants actually had acute hepatitis. Alcoholic Liver Disease A double-blind placebo-controlled study performed in 1981 followed 106 Finnish soldiers with alcoholic liver disease over a period of 4 weeks. The treated group showed a significant decrease in elevated liver enzymes and improvement in liver histology, as evaluated by biopsy in 29 subjects. Two similar studies provided essentially equivalent results. However, a 3-month randomized double-blind study of 116 people showed little to no additional benefit, perhaps because most participants reduced their alcohol consumption and almost half stopped drinking entirely. Another study found no benefit in 72 patients followed for 15 months. Liver Cirrhosis Study results conflict on whether milk thistle is helpful in liver cirrhosis. A double-blind, placebo-controlled study of 170 individuals with alcoholic or non-alcoholic cirrhosis found that in the group treated with milk thistle the 4-year survival rate was 58% as compared to only 38% in the placebo group. This difference was statistically significant. A double-blind, placebo controlled trial that enrolled 172 individuals with cirrhosis for 4 years also found reductions in mortality, but they just missed the conventional cutoff for statistical significance. And a 2-year, double-blind, placebo-controlled study of 200 individuals with alcoholic cirrhosis found no reduction in mortality attributable to the use of milk thistle. Other double-blind studies of cirrhotic individuals have found improvements in tests of liver function although one did not. Protection from Medications That Damage the Liver Numerous medications can injure or inflame the liver. Preliminary evidence suggests that milk thistle might protect against liver toxicity caused by drugs such as acetaminophen, Dilantin (phenytoin), alcohol, and phenothiazines. However, according to a 12-week double-blind study of 222 individuals, milk thistle does not seem to prevent the liver inflammation caused by the anti-Alzheimers drug Cognex (tacrine).

The standard dosage of milk thistle is 200 mg 2 to 3 times a day of an extract standardized to contain 70% silymarin. There is some evidence that silymarin bound to phosphatidylcholine may be better absorbed. This form should be taken at a dosage of 100 to 200 mg twice a day. Warning: Considering the severe nature of liver disease, a doctors supervision is essential. Also, do not inject milk thistle preparations that are designed for oral use!

Milk thistle is believed to possess very little toxicity. Animal studies have not shown any negative effects even when high doses were administered over a long period of time. A study of 2,637 participants reported in 1992 showed a low incidence of side effects, limited mainly to mild gastrointestinal disturbance.However, on rare occasions severe abdominal discomfort may occur. On the basis of its extensive use as a food, milk thistle is believed to be safe for pregnant or nursing women and researchers have enrolled pregnant women in studies. However, safety in young children, pregnant or nursing women, and individuals with severe renal disease has not been formally established. No drug interactions are known. However, one report has noted that silibinin (a constituent of silymarin) can inhibit a bacterial enzyme called beta-glucuronidase, which plays a role in the activity of certain drugs, such as oral contraceptives. This could theoretically reduce their effectiveness.

If you are taking:

• Medications that could damage the liver: Milk thistle might be protective for some of these drugs.
• Oral contraceptives: Milk thistle might reduce their effectiveness.