Milk thistle has long been associated with being beneficial to the liver. It has been used by herbalists and homeopathic practitioners for centuries. This flowering plant of the daisy family is also known as Silybum marianum. The active substances include the antioxidants silymarin and silybin. Milk thistle can be bought over the counter as a tea or tablets and is often used to help relieve symptoms of over indulgence of food and drink. In terms of treating fatty liver disease, what does the evidence show?
Lab-based studies and animal studies have found encouraging results regarding the benefits of milk thistle on protecting the liver from damage induced by toxic chemicals. Such studies have also shown milk thistle can help accelerate cell regeneration in the liver. However, when it comes to studies conducted in humans, there is less convincing evidence available.
Some human studies have reported that silymarin has beneficial effects in individuals with non-alcoholic fatty liver disease (NAFLD). For example, milk thistle has been shown to decrease oxidative damage to liver cells (Anstee 2012) and reduce inflammation in the liver (Cacciapuoti et al, 2013). Indeed, some studies have found benefits among patients with NAFLD taking a supplement of silymarin alone or along with vitamin E in regards to improved insulin resistance and reduced inflammation and liver damage (Abenavoli & Bellentani, 2013).
In terms of reviewing and assessing evidence, Cochrane Reviews are considered the gold standard. A recent Cochrane Review (Lombardi et al, 2017) was conducted on the effectiveness of pharmacological treatments for people with NAFLD. This review examined the evidence for a variety of supplements including milk thistle. The reviewers concluded that the quality of evidence was very low and therefore it remains unclear as to the effectiveness of such treatments for people with NAFLD.
If you’re considering taking milk thistle to treat the liver disease, it is important to discuss this with your doctor as milk thistle can alter the way some drugs are broken down in the liver.
So although some studies show encouraging findings that suggest milk thistle is beneficial for people with the fatty liver disease, more well-designed studies with a sufficient number of participants are needed to confirm the short and longer-term benefits.