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. Health Benefits Treat acute and chronic liver disease. Milk thistle "cleanses" and therefore fortifies the liver, a vital organ responsible for processing everything from nutrients in foods to medications and chemical pollutants. The herb partly accomplishes this task by preventing a reduction in concentrations of glutathione, an amino-acidlike compound that is critical to neutralizing toxins. Some studies indicate that milk thistle can actually increase glutathione levels by as much as 35%. In addition, silymarin alters the outer membrane of liver cells in such a way that toxins are barred from entering. It even encourages the formation of new, healthier liver cells to replace old, damaged ones. Various types of liver damage benefit from these remarkable properties, and the herb has repeatedly demonstrated its power to do so. Treat alcohol-related liver problems. Excessive alcohol intake depletes the amount of toxin-neutralizing glutathione in the liver and can cause severe scarring and dysfunction, a condition called cirrhosis. Milk thistle not only boosts glutathione levels, it also helps to actually repair the liver by promoting the growth of new cells in this large and vital organ.