Milk thistle seeds contain a powerful phytonutrient called, silymarin, which is increasingly being recognized for its’ wide-range of anti-cancer, anti-inflammatory, anti-oxidative and protective effects against various drugs and toxins. Most studies point to silibinin (also called, silybin) as the main active polyphenol compound in sylimarin extracts.
**Read more about polyphenols in a previous post**
Milk thistle protects the liver:
- Hepatitis (alcoholic, hepatitis B and C viruses): although commonly used by patients for these conditions, the quality of studies to date have been weak (recent study showed no benefit in patients with hepatitis C)
- Toxin-induced liver damage (drugs, industrial chemicals, liver-toxic chemotherapy regimens, poisonous “death cap” mushrooms,etc.)
Milk thistle protects and repairs kidney damage:
- A recent study demonstrated the efficacy of using milk thistle in the treatment of kidney damage (nephropathy) due to diabetes.
- Another recent study demonstrated protection against cisplatin chemotherapy-induced nephropathy.
Milk thistle can also reduce insulin resistance, blood sugar levels (HbA1c) and “bad” LDL cholesterol, in diabetics.
- see reference
Milk thistle has anti-cancer activity against numerous cancer cell types:
- prostate cancer
- breast cancer
- cervical cancer
- ovarian cancer
- colon cancer
- lung cancer
- liver cancer
- skin cancer
Milk thistle has also been shown to enhance the efficacy of chemotherapy (cisplatin and doxorubicin) on certain cancers.
- see reference
**Spoiler Alert: As with all preclinical data, milk thistle has not yet been proven effective as an anti-cancer therapy in humans (all the above studies were conducted with cell cultures and animal studies), so we have to remain optimistically cautious in our interpretations.**
Latest Study (2013):
Milk thistle protects against skin cancer in at least two ways (study):
- increases cell death in skin cells that have been damaged by UVA radiation (which comprises 95% of the rays from the sun)
- increases the repair of sun damaged skin cells from UVB radiation (which comprises 5% of the rays from the sun)
How Is It Used?
The supplement is available as a capsule, tablet, powder, and liquid extract. Powdered milk thistle can be made into a tea. A typical daily dose ranges from 140 to 600 milligrams of silymarin, usually divided into 2 or 3 doses (references: American Cancer Society and Mayo Clinic); although, there are no well-established, standard dose levels.
Side Effects & Precautions:
- Milk thistle is well-tolerated with few, if any, serious side effects.
- May cause: diarrhea, nausea, bloating, gas, upset stomach.
- Drug interactions are possible with milk thistle extracts. As with all polyphenol flavanoid compounds, silymarin is metabolized by the liver enzyme “Cytochrome P-450” which also is responsible for metabolizing many pharmacologic drugs. Taking silymarin along with any of those drugs may increase the toxicity of those drugs. Studies show, however, that the dose of milk thistle extract that inhibits Cytochrome P-450 is high and not likely able to be achieved with oral intake. One exception was recently identified with a potential interaction with the blood thinner, warfarin (milk thistle extract slowed the metabolism of warfarin, increasing the risk of bleeding.)
If you have an allergy to ragweed, chrysanthemums, marigolds, or daisies, you should avoid milk thistle. Milk thistle may cause a rash or lead to severe allergic reaction.
Since milk thistle may mimic the effects of estrogen, some women should avoid this herb. This includes women who have fibroid tumors or endometriosis. Additionally, women with breast, uterine, and ovarian cancers should not take milk thistle. (per WebMD)
- Memorial Sloan-Kettering Cancer Center (About Herbs)
- National Cancer Institute (PDQ)
- Mayo Clinic (NaturalStandard monograph)
- Examine.com (nice review of references and studies on milk thistle)