Milk Thistle

Milk thistle is a purple-flowered plant. Its sap and seeds contain the active ingredient silymarin, a potent antioxidant Antioxidants The human body needs various vitamins and minerals in order to thrive. Many of these nutrients can be found in whole, non-processed foods such as fruits and vegetables. However, most modern... read more and a term often used interchangeably with milk thistle. Antioxidants protect cells against damage by free radicals, which are highly chemically active by-products of normal cell activity.

(See also Overview of Dietary Supplements Overview of Dietary Supplements Dietary supplements are used by about 75% of Americans. They are the most common therapies included among integrative medicine and health (IMH) and complementary and alternative medicine (CAM)... read more .)

Milk thistle is claimed, among various other potential health benefits, to protect the liver from damage by viruses, toxic substances (such as alcohol and the toxins from death cap mushrooms), and certain drugs that are toxic to the liver (such as acetaminophen). Thus, people take milk thistle to prevent and treat mushroom poisoning Mushroom (Toadstool) Poisoning Many species of mushroom are poisonous and can cause different symptoms depending on the type of mushroom. Different species of mushrooms produce different toxins with different effects. Even... read more and other liver disorders, such as cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more and hepatitis C Overview of Hepatitis Hepatitis is inflammation of the liver. (See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.) Hepatitis is common throughout the world. Hepatitis can be Acute (short-lived) read more .

Milk thistle also may cause a slight to moderate decrease in blood sugar and hemoglobin A1C (HbA1C) in people with type 2 diabetes Type 2 diabetes Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Symptoms of diabetes may... read more .

Well-designed scientific studies do not show that milk thistle significantly benefits people with a liver disorder or decreases death due to liver toxicity.

Some studies have found that milk thistle decreased fasting glucose and HbA1C, but it is not clear whether it is recommended for people who have diabetes or poor insulin sensitivity (prediabetes).

Milk thistle may decrease diabetes-related complications such as fatty liver and proteinuria. Milk thistle may also lower cholesterol. It is often combined with other supplements, such as berberine.

No serious side effects have been reported, although gastrointestinal upset may occur. Also, people who have allergies to chrysanthemums, marigolds, and daisies may also have allergic reactions to milk thistle.

Women who have hormone-sensitive conditions (such as breast, uterine, or ovarian cancer; endometriosis Endometriosis In endometriosis, patches of endometrial tissue—normally occurring only in the lining of the uterus (endometrium)—appear outside the uterus. Why endometrial tissue appears outside the uterus... read more ; or uterine fibroids Uterine Fibroids A fibroid is a noncancerous tumor of the uterus that is composed of muscle and fibrous tissue. Uterine fibroids are very common, occurring in approximately 70% of White women and 80% of Black... read more ) should avoid milk thistle.

Milk thistle may increase the effects of drugs that decrease blood sugar levels (hypoglycemic drugs) and may interfere with drugs used to treat human immunodeficiency virus (HIV) infection (such as indinavir or saquinavir). Milk thistle may increase the effects of warfarin, sometimes resulting in bleeding. Milk thistle may increase the blood levels of drugs that have certain chemical similarities (such as some chemotherapy drugs, calcium channel blockers, and some antibiotics).

There is no clear evidence to support the claims that milk thistle benefits people with a liver disorder, diabetes, prediabetes, any other disorder.

Milk thistle may lower blood sugar levels in people with type 2 diabetes; therefore, people with diabetes should consult their doctor before taking milk thistle. Pregnant women and women who have hormone-sensitive conditions should consult with their doctor before taking milk thistle.