Milk thistle has been used as a natural remedy to treat liver problems, including fatty liver disease, for centuries. Here's everything you need to know about it.
While milk thistle is an age-old herbal remedy for fatty liver disease, the medical community is not entirely satisfied that there is enough scientific evidence to conclusively prove that it is an effective treatment. Some studies have shown encouraging results, but further research is required.
What Is Milk Thistle?
Milk thistle is a pretty but prickly plant that is often treated as a weed. Its green leaves have white streaks on them and if crushed, they discharge a milky white liquid which gives the plant its name despite its pinkish-purple thistle.
Milk Thistle Supplements
Milk thistle contains a group of bioflavanoids called silymarin, which consists of the compounds silibinin, silidianin and silicristin. While people often refer to milk thistle as silymarin, they're not exactly the same thing.
Silymarin is believed to have antioxidant, antifibrotic and anti-inflammatory properties that protect the liver, making it one of the most widely used herbs for fatty liver and other liver problems in the U.S. It is believed to help the liver repair cells that are damaged by alcohol and other toxins and protect liver cells against further damage. It is also believed to bring down inflammation.
Silymarin supplements are available in many forms, including powder, liquid, pills and capsules. They are consumed as is or can be added to tea, smoothies or water. Silymarin makes up roughly 70 to 80 percent of the supplements.
Understanding Fatty Liver Disease
Fatty liver disease is a health condition marked by fat deposits in the liver. While frequent excess alcohol consumption can cause fat to build up in the liver, the term fatty liver disease is usually used to refer to nonalcoholic fatty liver disease (NAFLD), which is often associated with obesity, diabetes, high cholesterol levels or high blood pressure.
If people with NAFLD have damaged liver cells and inflammation in their liver, the condition is referred to as nonalcoholic steatohepatitis (NASH). NASH is a more serious version of fatty liver disease and could cause cirrhosis, which over time could result in liver failure.
Fatty liver disease is called a silent disease because it often does not show any symptoms. However, it is estimated that 10 to 20 percent of Americans have NAFLD and 2 to 5 percent have NASH, according to Johns Hopkins Medicine.
Treating Fatty Liver Disease
Treating fatty liver usually involves lifestyle changes like more exercise, a healthier diet and weight loss if the patient is overweight. Losing 3 to 5 percent of body weight can help reduce fat in the liver, although sometimes it may have to be up to 10 percent of body weight to reduce inflammation in the liver, according to the National Institutes of Health.
Foods with saturated fats like red meat and full-fat dairy are to be avoided and replaced with foods with unsaturated fats like avocados, olive oil, nuts and fish. Refined carbs are to be replaced with healthy, complex carbs like whole grains, root vegetables and legumes.
Patients may also be prescribed medication to manage their cholesterol, blood glucose and insulin levels, depending on whether they have or are at risk for other medical conditions as well.
Milk Thistle for Fatty Liver
A small March 2013 study published in the World Journal of Hepatology found that patients who took oral silymarin supplements twice a day for six months saw an improvement in their fatty liver condition.
Another small study, published in the journal Drugs in R&D in March 2015 found that patients who undertook a diet and fitness regimen saw considerable improvement in their fatty liver condition, but that patients who undertook the same diet and fitness regime and took silymarin and vitamin E supplements saw even more improvement.
However, the medical community hasn't been entirely satisfied with the research on silymarin supplements and whether they are actually beneficial for the liver. According to the University of Maryland Medical Center, while a number of animal studies have shown that milk thistle can help protect the liver, the results of human studies have been mixed.
They note that while most studies show that milk thistle improves liver function and increases survival in people with cirrhosis or chronic hepatitis, problems in the design of the studies like small numbers of participants and differences in dosing and duration of treatment, make it hard to draw any real conclusions.
Is Milk Thistle Safe?
Milk thistle is considered to be safe for most people, with only mild side effects like nausea, gas, diarrhea, loss of appetite, headache and itchiness. It can mimic estrogen, so it is not advised for people with uterine fibroids, endometriosis and hormone-related cancers like breast, uterine, ovarian or prostate cancer. Pregnant and breastfeeding women should avoid it as well.
Some people get rashes when they touch milk thistle. People who are allergic to other plants in the same family, like ragweed, chrysanthemums, marigolds and daisies may not be able to take milk thistle. It may also lower blood sugar, so people who have diabetes or low blood sugar (hypoglycemia) should consult a doctor before taking it.
While herbs have been used for centuries to treat medical conditions, you should consult your health care provider before you take any herbal supplements because they may interact with other medication you are taking.
Milk thistle is known to interact with some antipsychotic drugs, birth control pills and hormone replacement therapies, among others. It may also interfere with medicines for allergies, high cholesterol and anxiety as well as some blood thinners, cancer medications and other drugs that are broken down in the liver.
You should also consult your doctor for the appropriate milk thistle dosage for fatty liver.
- University of Maryland Medical Center: “Milk Thistle”
- University of Rochester Medical Center: “Milk Thistle”
- Johns Hopkins Medicine: “Nonalcoholic Fatty Liver Disease”
- U.S. National Library of Medicine: “Silymarin in Nonalcoholic Fatty Liver Disease”
- U.S. National Library of Medicine: “Efficacy of Lifestyle Changes in Subjects With Nonalcoholic Liver Steatosis and Metabolic Syndrome May Be Improved With an Antioxidant Nutraceutical: A Controlled Clinical Study”
- U.S. National Library of Medicine: “The Therapeutic Effect of Silymarin in the Treatment of Nonalcoholic Fatty Disease: A Meta-Analysis (PRISMA) of Randomized Control Trials”
- Invasive Plant Atlas of the United States: “Blessed Milkthistle”
- National Institutes of Health: "Treatment for NAFLD and NASH"