Milk Thistle is a herbaceous annual or biennial plant with a dense-prickly flower head and reddish-purple tubular flowers. It is native to the Mediterranean region and has been naturalized in Central Europe, North and South America, and Southern Australia. Milk Thistle has an extensive history of use as an edible plant. In the 1st century AD, Pliny the Elder reported its use for supporting liver health. Theosophists (IV century BC) and Dioscorides (1st century AD) also wrote of its value. The English herbalist, Nicholas Culpeper (1650) claimed it was effective for supporting the normal functioning of the liver. At the turn of the 20th century, Eclectic physicians also used Milk Thistle to support healthy liver function. Much of the modern day research has been conducted in Germany where it is an approved herb in The German Commission E Monographs.*
What is Milk Thistle Used for?
Numerous scientific studies have explored Milk Thistle and a group of its constituents called summarily. Many of these clinical studies have demonstrated that this herb supports healthy liver function and provides powerful antioxidant protection. A primary constituent of silymarin called silibinin also helps to support healthy liver function, encouraging healthy cholesterol synthesis by the liver.* In addition to its well-recognized role in promoting liver health, key constituents in Milk Thistle also help to maintain normal kidney function and promote optimal immune function. Limited research suggests that this herb may also support healthy prostate function, and encourage a vital gastrointestinal tract by protecting it from free radical damage. More research is warranted to support the use of this herb for supporting its role beyond enhancing healthy liver function.*
What are the benefits of milk thistle?
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Milk thistle is used as a natural remedy to treat a range of health conditions. But are there any proven health benefits of milk thistle?
The active ingredient in milk thistle is called silymarin. Milk thistle is also known as Mary thistle or holy thistle. It is mainly used to treat liver problems, but some people claim it can lower cholesterol and help manage type 2 diabetes.
This article explores 10 potential milk thistle benefits and examines whether there is any scientific evidence to support its use. It also looks at how to use milk thistle and whether there are any risks to consider.
What is milk thistle?
Milk thistle is available in a range of forms, and is most popular as a supplement or in tea.
Milk thistle is a flowering plant that comes from the same family of plants as the daisy. It grows in Mediterranean countries and is used to make natural remedies.
Different parts of the milk thistle plant may be used to treat various health conditions. The most common use of milk thistle is for liver problems. Some claim it can help treat:
Other potential health benefits include protecting heart health by lowering cholesterol levels and helping people manage type 2 diabetes.
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Ten health benefits of milk thistle
1. Supports liver health
One of the most common uses of milk thistle is to treat liver problems. A 2016 study found that milk thistle improved diet-induced liver damage in mice. More evidence is needed to prove that milk thistle benefits human livers in the same way.
However, researchers theorize that it does. The active ingredient in milk thistle, silymarin, acts as an antioxidant by reducing free radical production. Scientists think this creates a detoxifying effect, which is why it is milk thistle may be beneficial for liver problems.
Until more research is carried out, however, milk thistle is not recommended as the primary treatment option for liver problems. But it may be a helpful complementary treatment to try.
2. Promotes skin health
Milk thistle oil may be used topically to improve skin health.
Milk thistle may help to promote healthy skin. A 2015 study found that milk thistle helped improve inflammatory skin conditions when applied to the skin of mice.
Milk thistle was also found to have antioxidant and anti-aging effects on human skin cells in a laboratory environment in another study.
Further research on humans is needed to identify what benefits a person can expect from applying milk thistle to their skin.
3. Reduces cholesterol
High cholesterol can lead to problems with heart health and increase a person’s chance of stroke.
A 2006 study suggests milk thistle may play an important role keeping cholesterol levels down. It found that cholesterol levels were lower in people taking milk thistle to treat diabetes than those taking a placebo.
4. Supports weight loss
Initial animal research conducted in 2016 found that silymarin caused weight loss in mice that were fed a diet intended to cause weight gain.
This suggests milk thistle may be beneficial for those looking to lose weight. More research into the effects of milk thistle on weight loss in humans is needed to confirm this, however.
5. Reduces insulin resistance
A study on mice found milk thistle extract helped to reduce insulin resistance. Insulin resistance is a problem for people with type 2 diabetes.
Although this research suggests milk thistle could play a role in diabetes management, more research is needed to confirm whether milk thistle reduces insulin resistance and supports diabetes management.
6. Improves allergic asthma symptoms
The active ingredient in milk thistle can help to reduce inflammation. A 2012 study found that silymarin helped to protect against inflammation in the airways of mice with allergic asthma.
More research is needed to see if silymarin benefits asthma symptoms in humans.
7. Limits the spread of cancer
Milk thistle may help to stop the spread of certain types of cancer. A 2016 review found that milk thistle extract inhibited the growth of cancerous cells in colorectal cancer.
More research is needed to determine how milk thistle may be used to help fight cancer.
8. Supports bone health
Milk thistle tea may help to prevent bone loss caused by a lack of estrogen.
Milk thistle may play an essential role in supporting bone health. A 2013 study found that milk thistle helped to prevent bone loss.
The study looked specifically at bone loss caused by a deficiency in estrogen. It is not yet clear whether milk thistle is equally beneficial for bone loss with a different cause.
Further studies are needed before it is safe to conclude that milk thistle supports bone health in humans.
9. Improves cognition
A 2015 study found that milk thistle increased resistance to oxidative stress. Oxidative stress is a potential cause of Alzheimer’s disease.
In this way, milk thistle may help improve cognition and treat degenerative conditions that affect the mind. More research on humans is needed to confirm the effects of milk thistle on cognition.
10. Boosts the immune system
Milk thistle may help strengthen a person’s immune response and help them fight off infection.
A 2016 study on an animal model found that milk thistle extract improved the immunity when consumed. An older study found that milk thistle extract had a positive effect on immune response in humans.
More studies with human participants are needed before scientists can say with certainty that milk thistle boosts a person’s immune system.powered by Rubicon Project
How to use milk thistle
Milk thistle is available as a supplement from many health food stores. There is no standard dose of milk thistle, so it is best to read the dosage suggested on the packaging.
Milk thistle is also available as a tea. If drinking milk thistle tea, it is best to limit intake to 6 cups a day.
Risks and considerations
As milk thistle is a supplement, the United States Food and Drug Administration (FDA) do not regulate it in the same way as they regulate drugs. For this reason, it is important to buy milk thistle from reputable retailers.
As with any natural remedy, people should discuss using milk thistle with a doctor before taking it.
Milk thistle may interact with some medications. This is of particular concern if a person is already receiving treatment for liver conditions.
Milk thistle has a range of potential health benefits due to its active ingredient, silymarin, which is an antioxidant.
More research needs to be carried out before a definitive list of milk thistle benefits can be confirmed. That said, it is a healthful supplement that may be worth trying alongside conventional treatments.
It is always a good idea to speak to a healthcare professional before starting to use milk thistle or any other supplement, as it may interact with other medications or conditions.
Health Benefits of Milk Thistle
Herbal Remedy Commonly Used for Liver Health
Milk thistle (Silybum marianum) is a perennial herb believed to have medicinal properties. The seeds contain silymarin, a group of compounds said to have antioxidant and anti-inflammatory effects. Milk thistle is commonly used as a home remedy to treat liver problems, often under the presumption that it will “detoxify” the liver.
At present, there is not enough scientific data to say whether milk thistle can help the liver or not. While it is not without benefit, milk thistle doesn’t appear to exert a significant effect on either liver tissues or liver function.1
Milk thistle is also known by the names Saint Mary’s thistle, variegated thistle, and Scotch thistle. In traditional Chinese medicine, milk thistle is referred to as DA ji, while the seeds are called shui fei ji.
Although milk thistle is most often used for liver conditions, such as hepatitis and cirrhosis, the herb is believed some to prevent or treat high cholesterol, diabetes, heartburn, upset stomach (dyspepsia), hangover, gallbladder problems, menstrual pain, depression, and even certain types of cancer. Few of these claims are supported by hard evidence.
Some preliminary studies have suggested that silymarin may improve liver function by keeping toxic substances from binding to liver cells. However, studies on the milk thistle’s effectiveness in treating liver disorders have yielded mixed results.2
According to a comprehensive review of studies in the American Journal of Gastroenterology, milk thistle neither improves liver function nor reduces the risk of death in people with alcoholic liver disease, hepatitis B, or hepatitis C.
Several smaller studies have suggested that milk thistle may benefit people with mild, subacute (symptom-free) liver disease. An early study from Finland found that a four-week course of silymarin supplements lowered key liver enzymes in people with subacute disease, suggesting the liver was functioning more normally.3
Despite the positive findings, subsequent studies have been unable to replicate the results or demonstrate that milk thistle prescribed on its own would render the same effects.
Chronic Hepatitis C
Milk thistle is sometimes used by people with chronic hepatitis C (a viral infection characterized by the progressive scarring of the liver). In fact, a survey funded by the National Institutes of Health reported that 23 percent of 1,145 people with hepatitis C used herbal supplements, with milk thistle being by far the most common.4
According to the survey, people with hepatitis C reported fewer symptoms and a “somewhat better quality of life” when taking milk thistle despite having no measurable change in viral activity or liver inflammation.
A 2012 study published in the Journal of the American Medical Association (JAMA) confirmed this. Despite being well-tolerated in the study participants, silymarin (prescribed thrice-daily in 420- or 700-milligram doses) had no tangible effect on liver enzymes.
Given these contradictions, many scientists believe that milk thistle delivers something of a placebo effect in which a person feels an improvement in symptoms despite having no change in their clinical condition.5
Type 2 Diabetes
Several studies have suggested that milk thistle may be beneficial for people with diabetes, most notably in those with type 2 diabetes.
According to 2015 research published in Phytomedicine, a 45-day course of silymarin increased the antioxidant capacity and reduced generalized inflammation in adults with type 2 diabetes better than a placebo.
According to the study’s authors, the findings suggest that silymarin may reduce the oxidative stress typically associated with diabetes complications.6
A systematic review conducted in 2016 further concluded that the routine use of silymarin appears to reduce the fasting blood glucose and HbA1C levels, although the authors warned that the quality of the reviewed studies was poor.Natural Remedies for Diabetes Prevention
Possible Side Effects
Milk thistle may trigger a number of side effects, including headache, nausea, diarrhea, abdominal bloating, and gas. Less commonly, muscle aches, joint pain, and sexual dysfunction have been reported.
Allergic reactions are also possible. People with allergies to ragweed, daisies, artichokes, kiwi, or plants in the aster family may also be allergic to milk thistle. On rare occasion, milk thistle can cause a potentially life-threatening, all-body allergy known as anaphylaxis.
Call 911 or seek emergency care if you experience shortness of breath, rash, hives, rapid heartbeat, lightheartedness, or swelling of the face, tongue, or neck after taking milk thistle.
If left untreated, anaphylaxis can lead to shock, coma, cardiac or respiratory failure, or death.
Milk thistle may reduce your blood sugar, so it needs to be used with caution as it may trigger hypoglycemia (low blood sugar) in people on diabetes medications.7
Since milk thistle exerts a mild estrogen-like effect, people with hormone-sensitive conditions like endometriosis, uterine fibroid, or cancers of the breast, uterus, or ovaries should avoid the supplement. Milk thistle may also reduce the effectiveness of estrogen-based contraceptives.8
Milk thistle can change the way that your body metabolizes certain drugs in the liver, triggering interactions with:
Other interactions are possible. To avoid complications, always advise your doctor about any supplements or herbal remedies you are taking.
Dosage and Preparation
There are no guidelines directing the appropriate use of milk thistle. Milk thistle supplements are commonly sold as in capsule form but are also available as tablets, tea bags, and oral tinctures. Doses range from 175 milligrams to 1,000 milligrams. Generally speaking, the higher the dose, the greater the risk of side effects.
Combination remedies such as Iberogast drops (used to treat dyspepsia) and Barber tablets (formulated for diabetics) are considered effective with milk thistle doses of 10 milligrams and 210 milligrams, respectively. Higher doses don’t necessarily correspond to better results.
Dietary supplements containing milk thistle are sold in natural foods stores, drugstores, and stores specializing in herbal products. You can also purchase milk thistle products online.
What to Look For
Dietary supplements in the United States do not need to undergo the rigorous testing and research and testing that pharmaceutical drugs do. Because of this, the quality can vary from one supplement to the next.
To ensure quality and safety, choose products that have undergone testing and certification by an independent certifying body like the U.S. Pharmacopeia (USP), Consumer Lab, and NSF International. As an added layer of safety, opt for brands that have been certified organic under the regulations of the U.S. Department of Agriculture (USDA).
Be wary of dried whole milk thistle or milk thistle seeds, both of which are vulnerable to fungal contamination, according to research published in the International Journal of Food Microbiology.
By contrast, fungal contamination is rare in milk thistle tea bags, extracts, capsules, tablets, and soft gels.
Can you grow their own milk thistle?
Milk thistle is a hardy plant that grows well in all different environments, although it prefers high temperatures and dry conditions. The soil also needs to be well-drained.
To grow milk thistle, spread the seeds over the loose soil in the spring or fall. Milk thistle seeds only take only around two weeks to germinate. Since milk thistle grows in clumps, space each cluster of seeds about 12 inches apart. Milk thistle is drought resistant and needs very little watering.
Once the flowers have finished blooming, they will leave behind seed clusters. You can harvest these and extract the seeds by removing the fluffy
What is Milk Thistle?
Milk thistle is a plant that is native to Europe and was brought to North America by early colonists. Milk thistle is now found throughout the eastern United States, California, and South America. The plant grows up to 2 meters high and has large, bright purple flowers.
Milk thistle gets its name from the milky sap that comes out of the leaves when they are broken. The leaves also have unique white markings that, according to legend, were the Virgin Mary’s milk. The above ground parts and seeds are used to make medicine. The seeds are more commonly used.
Milk thistle is taken by mouth most often for liver disorders, including liver damage caused by chemicals, alcohol, and chemotherapy, as well as liver damage caused by Amanita phalloides (death cap) mushroom poisoning, jaundice, chronic inflammatory liver disease, cirrhosis of the liver, and chronic hepatitis.
Milk thistle is also taken by mouth for loss of appetite, heartburn (dyspepsia), gallbladder complaints, enlarged prostate (benign pro static hyperplane), a blood disorder called beta-thalami, and infertility.
Some people take milk thistle by mouth for diabetes, kidney damage caused by diabetes, hangover, diseases of the spleen, prostate cancer, inflammation in the lungs and chest, malaria, depression, uterine complaints, increasing breast milk flow, allergy symptoms, starting menstrual flow, obsessive-compulsive disorder (OCD), Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, high cholesterol, and menopausal symptoms.
People apply milk thistle to the skin for skin toxicity caused by radiation.
People use milk thistle intravenously (by IV) for Samaritan phalloides (death cap) mushroom poisoning.
In foods, milk thistle leaves and flowers are eaten as a vegetable for salads and a substitute for spinach. The seeds are roasted for use as a coffee substitute.