Most members of the thistle family are considered noxious weeds. However, the milk thistle is known for its medicinal properties. Research shows that it protects the liver from alcohol damage and actually helps liver cells regenerate in these cases. The herb may prove useful in treating certain types of cancer. However, it should be used with care. Side effects, allergies and interactions with drugs are possible, so check with your doctor before using milk thistle.
Chemical Constituents
Milk thistle contains a group of flavonoids which include silymarin, silibinin, silidianin and silicristin.
Purported Uses
Milk thistle has been used to protect the liver from alcohol and drug-induced damage, as an anti-inflammatory, an antioxidant and as an antidote to poisoning by the deathcap mushroom. It has also been used to treat cirrhosis, hepatitis and stomach upsets. It may be useful in treating prostate and colon cancer.
Research
In July 1989, Ferenci, et. al., published the results of a study in the Journal of Hepatology that showed that individuals treated with milk thistle over at least two years showed significantly higher four-year survival rates than those treated with placebos. In addition, silymarin helps with protein synthesis, and can assist in regeneration of liver cells. However, silymarin does not appear to be effective as a treatment for hepatitis or other forms of liver disease.
Huseini and colleagues published a clinical trial in Phytotherapy Research in 2006, which involved patients with Type II diabetes. It showed that milk thistle improved their glycemic profiles.
Preliminary studies indicate that milk thistle may be useful for colon and prostatic cancer. However, no clinical trials have been done to date to confirm these results. Animal studies also support the use of milk thistle as an antidote to poisoning by the deathcap mushroom. Research in this areas is preliminary at best.
Asghar and Masood published an in vitro study in the July, 2008 issue of the Pakistani Journal of Pharmaceutical Science suggesting that milk thistle has significant antioxidant properties. More work is needed in this area.
Side Effects and Toxicity
Diarrhea and uterine and menstrual stimulation are side effects of milk thistle use. Toxicity is rare but symptoms can include nausea, vomiting, sweating and weakness.
Allergic reactions to milk thistle are possible. If you have allergies to plants in the aster family, to kiwi or artichokes, or to silymarin or related compounds in milk thistle, you should avoid using this supplement. Handling milk thistle plants may cause rashes on exposed skin. Severe allergic reactions with difficulty breathing, chest pain or tightness, and swelling of the mouth, lips or throat can occur. In these cases, seek medical help immediately.
Precautions
Milk thistle may inhibit the cytochrome P-450 3A4 enzyme, which affects the metabolism of some drugs, such as ketoconazole, itraconazole, erythromycin, triazolam and some HIV drugs. Persons who are taking these medications should check with their physicians before beginning the supplement. Taking milk thistle with these drugs can cause adverse reactions or toxicities.
Pregnant or breast feeding women and children should not use milk thistle. Persons taking Dilantin, anti-psychotic drugs, anti-anxiety drugs, anti-platelet drugs, anticoagulants, and some anti-cancer drugs should not use milk thistle.
References
- Mayo Clinic: Milk thistle (Silybum marianum)
- Memorial Sloan-Kettering Cancer Center: Milk Thistle
- National Center for Complementary and Alternative Medicine: Milk Thistle
- Science Direct: Abstract Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver
- Wiley On-line Library: Abstract The efficacy of Silybum marianum (L.) Gaertn. (silymarin) in the treatment of type II diabetes: a randomized, double-blind, placebo-controlled, clinical trial
