Bull thistle, cardo blanco, Cardui mariae fructus, Cardui mariae herba, Cardum marianum L., Carduus marianus L., Chardon-Marie, emetic root, flavonolignans, Frauendistel, Fructus Silybi mariae, fruit de chardon Marie, heal thistle, holy thistle, isosilibinin, isosilybin, kanger, kocakavkas, kuub, lady's thistle, Legalon©, Marian thistle, mariana mariana, Mariendistel, Marienkr©rner, Mary thistle, mild thistle, milk ipecac, natursil, natursilum, Our Lady's thistle, pig leaves, royal thistle, shui fei ji, silidianin, Silybi mariae fructus, silybin, silybinin, Silybum marianum, silychristin, silymarin, snake milk, sow thistle, St. Mary's thistle, thisylin, Venus thistle, variegated thistle, wild artichoke.
Milk thistle has been used medicinally for over 2,000 years, most commonly for the treatment of liver and gallbladder disorders. A flavonoid complex called silymarin can be extracted from the seeds of milk thistle and is believed to be the biologically active component. The terms "milk thistle" and "silymarin" are often used interchangeably.
Milk thistle products are popular in Europe and the United States for various types of liver disease. Although numerous human trials have been published, most studies have not been well designed or reported.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Multiple studies from Europe suggest benefits of oral milk thistle for cirrhosis. In experiments up to five years long, milk thistle has improved liver function and decreased the number of deaths that occur in cirrhotic patients. Although these results are promising, most studies have been poorly designed. Better research is necessary before a strong recommendation can be made.
Liver disease (chronic)
Several studies of oral milk thistle for hepatitis caused by viruses or alcohol report improvements in liver tests. However, most studies have been small and poorly designed. More research is needed before a strong recommendation can be made.
Acute viral hepatitis
Research on milk thistle for acute viral hepatitis has not provided clear results, and milk thistle cannot be recommended for this potentially life-threatening condition.
Amanita phalloides mushroom poisoning
Milk thistle has been used traditionally to treat Amanita phalloides mushroom poisoning. However, there are not enough reliable studies in humans to support this use of milk thistle.
There are early reports from laboratory experiments that the chemicals silymarin and silibinin in milk thistle reduce the growth of human breast, cervical, and prostate cancer cells. There is also one report of a patient with liver cancer who improved following treatment with milk thistle. However, this research is too early to draw a firm conclusion, and effects have not been shown in high-quality human trials.
Diabetes (in patients with cirrhosis)
A small number of studies suggest possible improvements of blood sugar control in cirrhotic patients with diabetes. However, there is not enough scientific evidence to recommend milk thistle for this use.
An herbal preparation containing milk thistle may be effective in decreasing symptoms of functional dyspepsia. However, milk thistle alone has not been researched.
Although animal and laboratory research suggests cholesterol-lowering effects of milk thistle, human studies have provided unclear results. Further studies are necessary before a firm recommendation can be made.
Liver damage from drugs or toxins
Several studies suggest possible benefits of milk thistle to treat or prevent liver damage caused by drugs or toxic chemicals. Results of this research are not clear, and most studies have been poorly designed. Therefore, there is not enough scientific evidence to recommend milk thistle for this use.
An herbal preparation containing milk thistle may be effective in decreasing menopausal symptoms. However, milk thistle alone has not been researched.
*Key to grades:
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below. Acute liver injury, amiodarone toxicity reactions, antibacterial, asthma, bad breath, bleeding, bronchitis, constipation, diabetic nerve pain, eczema, fatty liver, gallbladder disease, gallstones, hangover, hemorrhoids, hyperthyroidism, immunomodulator, immunostimulant, inflammation, ischemic injury, liver protection, loss of appetite, malaria, menstrual problems, nutrition (dietary supplement), physical work capacity, plague, psoriasis, radiation toxicity, snakebites, spleen disorders, sunscreen, tumors, ulcers, varicose veins.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (over 18 years old)
Silymarin (Legalon©) 230-600 milligrams per day divided into two to three doses has been studied.
Silipide© (IdB 1016) 160-480 milligrams per day in silybin equivalents has also been studied.
Children (under 18 years old)
There is not enough scientific data to recommend milk thistle for use in children.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
People with allergies to plants in the aster family (Compositae, Asteraceae) or to daisies, artichokes, common thistle, kiwi, or to any of milk thistle's constituents (silibinin, silychistin, silydianin, silymonin, siliandrin) may have allergic reactions to milk thistle. Anaphylactic shock (a severe allergic reaction) from milk thistle tea or tablets has been reported in several patients. Overall, silymarin has a good safety record with rare case reports of gastrointestinal disturbances and allergic skin rashes published.
Side Effects and Warnings
Milk thistle appears to be well tolerated in recommended doses for up to six years. Some patients in studies have experienced stomach upset, headache, and itching. There are rare reports of appetite loss, gas, heartburn, diarrhea, joint pain, and impotence with milk thistle use. One person experienced sweating, nausea, stomach pain, diarrhea, vomiting, weakness, and collapse after taking milk thistle. This reaction may have been due to an allergic reaction, and improved after 24 hours. High liver enzyme levels in one person taking milk thistle returned to normal after the person stopped taking the herb.
In theory, milk thistle may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugars. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.
Theoretically, because milk thistle plant extract might have estrogenic effects, women with hormone sensitive conditions should avoid milk thistle above ground parts. Some of these conditions include breast, uterine, and ovarian cancer, endometriosis, and uterine fibroids. The more commonly used milk thistle seed extracts are not known to have estrogenic effects.
Exacerbation of hemochromatosis has been associated with ingestion of milk thistle.
Pregnancy and Breastfeeding
Milk thistle has been used historically to improve breast milk flow, and two brief studies of milk thistle in pregnant women reported no side effects. However, there is not enough scientific evidence to support the safe use of milk thistle during pregnancy or breastfeeding at this time.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Animal studies suggest that milk thistle may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased in the blood, and may cause increased effects or adverse reactions. Many types of drugs may be affected. Individuals should speak with a qualified healthcare provider to obtain a list of these drugs and their possible interactions. In theory, milk thistle may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.
A possible interaction with phenytoin (Dilantin©) has been reported with milk thistle. However, the facts are unclear.
Milk thistle ingredients have been reported to prevent amiodarone toxicity in animal studies. Based on laboratory and animal study, milk thistle may increase the effects of chemotherapy drugs like doxorubicin, cisplatin, and carboplatin. Milk thistle may interact with hormonal agents, alcohol, or antiretroviral drugs.
Interactions with Herbs and Dietary Supplements
Animal studies suggest that milk thistle may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements may be too high in the blood. It may also alter the effects that other herbs or supplements have on the P450 system.
Milk thistle may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Milk thistle may also interact with herbs and supplements with hormonal, antiretroviral or antioxidant effects. Milk thistle may interfere with iron absorption and slow calcium metabolism.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard Bottom Line Monograph, Copyright © 2011 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
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Copyright © 2011 Natural Standard (www.naturalstandard.com)
Copyright © 2011 Natural Standard (www.naturalstandard.com)