Milk thistle (Silybum marianum)
Original Article: http://www.mayoclinic.com/health/silymarin/NS_patient-milkthistle
Milk thistle (Silybum marianum)
Natural Standard® Patient Monograph, Copyright © 2013 (www.naturalstandard.com). All Rights Reserved. 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.
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.
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;ouml;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.
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.
CirrhosisMultiple 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 hepatitisResearch 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 poisoningMilk 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.
CancerThere 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.
Dyspepsia (indigestion)An herbal preparation containing milk thistle may be effective in decreasing symptoms of functional dyspepsia. However, milk thistle alone has not been researched.
High cholesterolAlthough 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 toxinsSeveral 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.
Menopausal symptomsAn herbal preparation containing milk thistle may be effective in decreasing menopausal symptoms. However, milk thistle alone has not been researched.
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)
Uses based on tradition or theory
The below uses are based on tradition or scientific theories. 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.
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.
This patient information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
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- Lawrence V, Jacobs B, Dennehy C, et al. Report on milk thistle: effects on liver disease and cirrhosis and clinical adverse effects. Evidence Report/Technology Assessment No. 21 (Contract 290-97-0012 to the San Antonio Evidence-based Practice Center, based at the University of Texas Health Science Center at San Antonio, and The Veterans Evidence-based Research, Dissemination, and Implementation Center, a Veterans Affairs Services Research and Development Center of Excellence). AHRQ Publication No. 01-E025. Rockville, MD: Agency for Healthcare Research and Quality. October 2000.
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