Milk thistle is a purple and pink flowering plant whose medicinal benefits have been used for thousands of years. According to the National Cancer Institute, the fruit and seeds of a milk thistle are used to make remedies for liver and bile duct ailments and alleviate the toxicity of chemotherapy. Because the U.S. Food and Drug Administration has not yet approved the use of milk thistle in treatment of cancer or any other medical condition, milk thistle is only available in the United States as an herbal dietary supplement.
Milk thistle is of the genus Silybum marianum and grows as an annual or biennial plant. It is native to the Mediterranean region but can now be found in various parts of the world, including the United States. A flavonoid complex (a class of plant secondary metabolites), Silymarin, is the active ingredient in milk thistle that gives it its beneficial powers. Silymarin is an antioxidant that is extracted from the milk thistle's seeds and, as a term, often used interchangeably with the term "milk thistle."
According to the Mayo Clinic, milk thistle is most commonly used for treatment of liver and gallbladder disorders. Originally used as a supplement for alleviating menstrual problems, depression, varicose veins and as a way to increase breast milk production, the milk thistle's modern popularity comes from its application to the treatment of liver disease.
Milk thistle benefits may result from its reported ability to not only produce new cells but also stop the production of bad cells (in particular, cancer cells). As a result, it is used to treat liver cirrohosis, toxin-induced liver damage (mushroom toxicity), gallbladder disorders, chronic hepatitis (hepatitis C), high cholesterol, and cancer. Milk thistle may lower blood sugar levels.
According to the National Cancer Institute, milk thistle has the power to make chemotherapy more effective and less toxic. It is known to slow down the growth rate of cancer cells.
Milk thistle is usually taken as capsules or tablets. According to the Mayo Clinic, adults aged 18 and older should take 230-600 milligrams of Silymarin per day, divided into two or three doses.
According to the Mayo Clinic, people who are allergic to daisies, artichokes, common thistle, kiwi or any of milk thistle's constituents (silibinin, silychristin, silydianin, silymonin, siliandrin) may be allergic to milk thistle. However, severe allergic reactions are rare. Milk thistle's side effects include appetite loss, heartburn, diarrhea, joint pain and gas but are also rare.