St Mary’s Thistle

Silybum marianum

St Mary’s thistle, otherwise known as milk thistle, derives the name from it’s spiked leaves with white veins which are said to carry the milk of the Virgin Mary.  The plant is native to Europe and grows in the wild in the United States and South America.

It has a long traditional use dating back to ancient times and has been touted as a remedy for such diverse conditions as ‘melancholia, liver ailments and snake bite.’

Written records prove that the medicinal benefits of St Mary’s thistle have been valued for more than 2000 years. As early as the first century, Romans were using the plant as a liver-protecting agent.

The plant was also frequently used throughout the Middle Ages; and the herbal literature of this period notes the medicinal properties of milk thistle seeds.

In the early seventeenth century, Nicholas Culpepper, a British herbalist, wrote about the value of the herb in treating ‘diseases of the liver and spleen’.  By the end of the next century, records show that American physicians were also prescribing the substance.

The leaves and stem of the milk thistle plant are edible, and can be used in salads or eaten raw. The plant was cultivated as a vegetable in Europe.

The active ingredient of the herb, Silymarin, is found in the ripe seeds of the plant.  Silymarin was first isolated from the milk thistle plant by German scientists in the 1960s.

In modern practice, St Mary’s thistle is used to treat indigestion and a variety of liver conditions.

St Mary’s thistle has a ‘hepatoprotective’ effect, that is, it protects the liver from damage.  It is thought to promote the growth of new liver cells, and to prevent toxins from penetrating through healthy liver cells by binding itself to the cell membranes.  Thus it is prescribed for cirrhosis, hepatitis, and other liver disorders.

A 2001 article reported that several clinical studies have demonstrated that individuals with cirrhosis who take daily doses of St Mary’s thistle extract have a lower mortality rate than those who took a placebo.  In other words, St Mary’s thistle significantly increased survival rates in patients with liver cirrhosis, (particularly alcoholic cirrhosis) in long-term clinical trials.

In other clinical trials of patients with alcoholic liver disease, treatment with St Mary’s thistle led to significant reduction in the elevated liver enzyme levels and improved antioxidant parameters.

It has been shown to reduce the toxic effect on the liver of a number of toxins including paracetamol, carbon tetrachloride and death cap mushrooms.  St Mary’s  thistle is the only known antidote for death cap mushroom (Amanita phalloides) poisoning.  Ingesting this deadly mushroom can destroy the liver by shutting down protein production in liver cells.  St Mary’s thistle seems to neutralise these toxins and protect the liver.

Clinical studies have shown that, in patients with toxic liver damage, St Mary’s thistle improved the results of liver function tests, as well as the unpleasant symptoms of nausea and itching skin.

Given pre and post- operatively, St Mary’s thistle prevented the increase of liver enzymes due to the toxic effects of the anaesthetics.

St Mary’s thistle reduced the liver damage of certain cholesterol lowering (lipotropic) drugs.
Liver function of patients with occupational toxic liver damage due to solvents, paints, and glues improved when given St Mary’s thistle.

In patients with gall stones or those in whom the gall bladder had been removed, St Mary’s thistle improved the quality of the bile compared to placebo.

In a double blind, placebo-controlled clinical trial, St Mary’s thistle improved all aspects of liver function in patients with acute or sub-acute liver disease.

In Europe, commission E approves use of St Mary’s thistle for digestive complaints, toxic liver damage, cirrhosis and chronic, inflammatory liver disease.

Cautions and Contraindications.
Known allergy to the Compositae family of plants.