Milk Thistle – Actions, Uses, and Cautions

Milk thistle, whose botanical name is silybum marianum, is a relative of the artichoke and burdock plants. It originated in the area around the Mediterranean Sea, but it now grows in Central Europe, North and South America, and Southern Australia.

All parts of the plant are edible – as long as the spines are removed. The leaves can be steamed or added to salads, the roots can be eaten raw or cooked, and the roasted seeds and scorched roots can be brewed to produce a coffee substitute.

The active ingredient in milk thistle, silymarin, seems to protect the liver by strengthening the outer membranes of liver cells. It also decreases fat deposits and stimulates protein synthesis, which itself assists the liver in making new cells, so it can help the liver repair itself. The silybinin component of silymarin has been shown to decrease the level of cholesterol in bile, which can help prevent – or relieve – the problem of gallstones. And milk thistle can enhance the functioning of the spleen and the blood vessels, so it can help improve circulation.

Milk thistle has been recognized and recommended as a liver tonic since the first century, when Pliny the Elder said it was useful for “carrying off bile.” It has also traditionally been used as a folk remedy for everything from anthrax, malaria, and the plague to inadequate lactation (production of breast milk). And in the Middle East it’s popular for skin problems, hemorrhoids, and worms.

Today the most common use of milk thistle is to assist recovery from infectious or inflammatory conditions of the liver, like hepatitis and environmental toxins, and to slow the degenerative process in cirrhosis of the liver – a condition which is usually caused by alcohol abuse. People with liver problems are usually advised to completely avoid alcohol. This may explain why tinctures – concentrated extractions – of milk thistle are more commonly made with glycerin than alcohol (which is the usual extracting ingredient).

Milk thistle can also be very useful for poisoning; it’s been known to protect from – and in at least one case reverse – damage from the usually-fatal deathcap mushroom, which is often mistaken for a more harmless variety. It’s also used for circulatory problems like varicose veins and hemorrhoids, and as an adjunct to treatment for gallstones.

In the case of hepatitis C, milk thistle has been given to patients also being treated with interferon – a very expensive, and potentially dangerous, antiviral and anticancer drug – and the results have been promising. But it’s necessary to be cautious here, as hepatitis C patients may have different and sometimes unpredictable reactions to standard drugs, herbs, and even foods.

Milk thistle has no known side effects except for a possible mild laxative effect when it’s taken in larger doses. If you’re concerned about this, or have any other doubts, it’s a good idea to consult with a trained herbalist or medical practitioner before taking it.