Milk thistle appears to be helpful, not harmful, to your liver due to its active ingredient, called silymarin. Silymarin appears to protect your liver against some types of damage. This substance also may prevent blockages that interfere with liver bile flow and promote production of new liver cells. However, there is insufficient evidence to rate milk thistle's effectiveness for treating liver complaints in people, according to the National Institutes of Health. Always consult a doctor before trying a new supplement.
Status
You'll find that milk thistle's status as a liver tonic varies throughout the world. In the United States, more high-quality clinical trials are needed to establish milk thistle's efficacy against liver disease, according to the National Center for Complementary and Alternative Medicine (NCCAM). However, in Germany milk thistle is approved by Commission E, that country's regulatory body for herbs, for treating liver complaints. Milk thistle is the most well-researched plant for use in treating liver disease, according to a 2010 scientific review published in "Phytotherapy Research."
Case Report and Considerations
It's important to discuss milk thistle with your doctor before taking it and to have your doctor check for adverse effects once you begin. For example, high liver enzyme levels have been reported in one person taking milk thistle, reports MayoClinic.com. The person's enzyme levels returned to normal when milk thistle was discontinued. Elevated liver enzymes are a possible indicator for inflammation or damage to cells in your liver. However, most often, elevated liver enzymes do not signal a serious or chronic liver problem, according to MayoClinic.com. Milk thistle generally is well tolerated when used in recommended doses, notes NCCAM. The most common side effects are gastrointestinal complaints and allergic reactions. This herb also may lower blood sugar levels and provide estrogenlike effects.
Use and Research
You'll find that milk thistle has been used in people to treat acute and chronic viral hepatitis, alcoholic liver disease and toxin-induced liver diseases, according to "Phytotherapy Research." Animal studies point to the active ingredient in milk thistle, silymarin, reducing liver injury caused by acetaminophen, iron overload, carbon tetrachloride, radiation, alcohol, phenylhydrazine, cold ischaemia and Amanita phalloides, notes lead review author L. Abenavoli. Laboratory studies indicate milk thistle benefits the liver by promoting growth of liver cells, protecting them, fighting cell-damaging oxidation and inhibiting inflammation, according to NCCAM.
Expert Insight
MayoClinic.com gives milk thistle a B rating for treating chronic liver disease and cirrhosis. The B rating means there is good scientific evidence to support those uses. Numerous European studies support using milk thistle for cirrhosis, though more research is necessary before a strong recommendation for this treatment can be made. Likewise, indications backing milk thistle for treating chronic liver disease are promising, but studies as of 2011 have had design flaws or were too small in size for firm conclusions to be drawn, advises MayoClinic.com. The clinic gives milk thistle a C rating for liver damage due to toxins or drugs, which means scientific evidence for this use remains unclear. Consult a health care provider before using milk thistle for any purpose, especially if you have a health condition such as a liver ailment.
References
- National Center for Complementary and Alternative Medicine: Milk Thistle
- "Phytotherapy Research"; Milk Thistle in Liver Diseases: Past, Present, Future; L. Abenavoli, et al.; 2010
- MayoClinic.com: Milk Thistle Safety
- MayoClinic.com: Elevated Liver Enzymes
- MedlinePlus: Milk Thistle
- "The Essential Herb-Drug-Vitamin Interaction Guide"; George T. Grossberg and Barry Fox; 2007
