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.
Ten health benefits of milk thistle
The potential health benefits of milk thistle are explored below.
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
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
More research is needed to see if silymarin benefits asthma symptoms in humans.
7. Limits the spread of 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
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.
More studies with human participants are needed before scientists can say with certainty that milk thistle boosts a person's immune system.
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.