Healers have used the prickly milk thistle plant to treat liver ailments for more than 2,000 years. Somehow these early practitioners figured out that preparations of this purple-flowered member of the sunflower family could stimulate the flow of bile from the liver, improving digestion and various liver-related ills.

Interestingly, bile and other bodily fluids, also known as humors, were once associated with different personality types. Because it was thought that black bile was inherent to a melancholic nature, milk thistle was prescribed for treating depression and melancholy (which actually means "black bile"). Today, the word "biliousness" and the phrase "having excess bile" are still used to describe negative personality traits.

While milk thistle is no longer seen as a remedy for melancholy, hundreds of medical studies have substantiated the fact that the herb does indeed protect and heal the liver. European physicians currently consider milk thistle a mainstay for liver disorders ranging from hepatitis to cirrhosis. But even though a 19th-century American medical group called the Eclectics prescribed milk thistle for liver ailments, it has never been widely used in the U.S. for healing purposes.

Milk thistle grows throughout the world (including North America) in both cultivated and wild form. Many sources refer to the herb, by its botanical name, Silybum marianum, as well as by its active compounds, collectively known as silymarin. Concentrated stores of silymarin are found in the herb's shiny black fruits (seeds), which are typically collected at summer's end.

Health Benefits

Although most widely associated with liver complaints, milk thistle is also being examined for treating a variety of other disorders, from gallstones and high cholesterol to skin cancers and allergy symptoms. As a potent antioxidant, the versatile milk thistle extract helps prevent highly reactive oxygen molecules called free radicals from damaging cells throughout the body, but especially in the liver, stomach, and intestines.