Milk thistle is a flowering herb related to the daisy and ragweed family. It is native to Mediterranean countries. It’s ironic that milk thistle is used as a dietary supplement often taken to help protect the liver, while it can be contaminated by high levels of mycotoxins that are potentially harmful to the liver.
This has again been confirmed by a recent report by the European Food Safety Authority looking at the presence of the two mycotoxins T2 and HT2 in the diet. They found that milk thistle contained about five times higher levels of the two mycotoxins than any other product tested, with 220 µg/kg (T2) and 370 µg/kg (HT2) on average for milk thistle compared to oats with 40 µg/kg (T2) and 90 µg/kg, the second highest contaminated product.
And it is not the first time that a dietary supplement of some sort is at the top of the contamination table for a range of harmful compounds. And still people take them to improve their health. What’s wrong?
A little bit of background
Milk thistle is a plant also known as Chardon de Marie, Holy Thistle, Lady’s Thistle, Lait de Notre-Dame, Marian Thistle, Mariendistel, Mary Thistle, Shui Fei Ji, Silibinin, and many other names (in case you are looking for it).
Silymarin is the main active ingredient in milk thistle. Silymarin is both an anti-inflammatory and antioxidant. But it is unclear what benefits, if any, silymarin may have in the body.
Irrespective of clear proof of any beneficial effects, milk thistle has been used in alternative medicine as a possibly effective aid in treating heartburn, or seasonal allergy symptoms. Other uses not proven with research have included treatment for malaria, mushroom poisoning, spleen or gallbladder problems, menstrual problems, liver problems, and other conditions.
There is not enough scientific evidence to say whether or not milk thistle can help liver problems. Some early research suggests milk thistle may aid people with alcohol-related liver disease. Other studies show no improvement in liver function in this group of people.
Some studies also show milk thistle may offer a possible benefit for people whose liver is damaged by industrial toxins, such as toluene and xylene.
However, more information is needed before it is possible to say that milk thistle actually benefits the liver.
Thus, let’s be clear that medicinal use of milk thistle compounds has not yet been supported by any regulatory authority. Still they are in common use all over the world.
Possible effect of mycotoxin contamination
Contamination of milk thistle with T2 and HT2 toxins have been reported from several parts of the world. T2 toxin and its deacetylated form HT2 toxin are members of the large family of trichothecenes. Fusarium species are the predominant moulds that invade cereal crops and produce T2 and HT2 under cool and moist conditions. Similar to most trichothecenes, T2 and HT2 not only inhibit protein synthesis and cell proliferation in plants, but also cause acute or chronic intoxication of humans and animals.
Toxic effects include growth retardation, myelotoxicity, hematotoxicity, and necrotic lesions on contact sites.
And this can be serious business.
Alimentary toxic aleukia (in simple terms a decrease in important white blood cells), a disease which is caused by trichothecenes, killed many thousands of USSR citizens in the Orenburg District in the 1940s. It was reported that the mortality rate was 10% of the entire population in that area.
During the 1970s it was proposed that the consumption of contaminated food was the cause of this mass poisoning. Because of World War II, harvesting of grains was delayed and food was scarce in Russia. This resulted in the consumption of grain that was contaminated with Fusarium moulds, which produced the two mycotoxins.
So what to do?
As for many dietary supplements it is probably best to stay away at least until any beneficial effect has been finally proven. There is also very little official oversight of the composition of any dietary supplement product. It has been proven again and again that they might contain several other compounds than what is declared on the label. Some that are themselves directly toxic.
So don’t gamble with your health!