Fatty liver disease is the accumulation of triglycerides within hepatocytes that exceeds 5% of liver weight.
Non-alcoholic fatty liver disease (NAFLD) is generally caused by excessive calorie/food intake. It is often known as a silent disease that produces no symptoms until it is in advanced stages.
NAFLD ranges from simple steatosis (simple fatty liver) to non-alcoholic steatohepatitis (NASH), ie. simple steatosis with inflammation. NASH can progress to liver cirrhosis and hepatocellular carcinoma (HCC), the end stage of liver disease.
NAFLD is the most prevalent type of chronic liver disease worldwide. Not only is the incidence of NAFLD rapidly rising but it’s occurring more often in children and adolescents. NAFLD is associated with obesity, type 2 diabetes, hyperlidemia, insulin resistance and metabolic syndrome.
Lifestyle modifications are the recommended approach to managing NAFLD. These include special diets, physical exercise and weight reduction. Currently, there are no pharmacologic agents approved for treatment of NAFLD.
Liver Protective Effects Of Milk Thistle
Milk thistle is a flowering herb native to the Mediterranean region. It has been used for more over 2,000 years as a traditional herbal remedy for liver diseases.
Silymarin is the primary compound in milk thistle that provides benefits for liver health. It is a group of flavonolignans that includes silybin, isosilybin, silydianin and silychristin. Silybin is the most active component and makes up 50-70% of silymarin.
Silybin posseses anti-oxidant, anti-inflammatory, antifibrotic and metabolic effects.
Mechanisms Of Silymarin/Silybin
- interferes with lipid peroxidation due to free radical scavenging and increases cellular content of glutathione
- increases membrane stability and regulates membrane permeability
- promotes liver regeneration
- inhibits fibrogenesis in the liver
- inhibits uptake of toxins
Clinical Studies On The Effects Of Milk Thistle On NAFLD
Two randomised clinical studies demonstrated that silymarin lowered liver enzymes, especially alanine aminotransferase (ALT): one study1 in NAFLD patients and the other study2 in NASH patients.
A randomised controlled pilot study3 compared the effects of metformin, pioglitazone and silymarin on treatment of NAFLD. The results showed that changes in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in silymarin group were more than that in the other 2 groups. The average difference between changes was significant between silymarin and metformin groups.
Silybin has been shown to have beneficial effects on liver function in preliminary studies.
Researchers in Italy conducted a series of studies to assess the efficacy of a complex of silybin-vitamin E phospholipids (silybin is conjugated with vitamin E and phospholipids to improve its antioxidant activity) on NAFLD patients. They found that the silybin vitamin E phospholipid complex
- improved liver enzyme levels, insulin resistance and liver damage in patients with NAFLD in a preliminary study4.
- improved liver enzyme levels, insulin resistance and markers of liver fibrosis, and significantly reduced ultrasonographic scores for liver steatosis in NAFLD patients in a pilot study5.
- improved liver enzymes, insulin resistance and liver histology in a multicenter clinical trial6.
Milk thistle is the most researched herbal treatment for liver diseases. Its active compounds (silymarin/silybin) exert protective effects on the liver.
All the above human studies showed that silymarin and its active constituent, silybin improved liver enzyme levels in NAFLD/NASH patients. Since silymarin has very low toxicity and there is no medical treatment for NAFLD/NASH, it could be a useful herbal remedy for NAFLD/NASH, in complementary with diet and physical exercise.
1. Silymarin in treatment of non-alcoholic steatohepatitis: A randomized clinical trial
2. The Efficacy of Silymarin in Decreasing Transaminase Activities in Non-Alcoholic Fatty Liver Disease: A Randomized Controlled Clinical Trial
3. Effects of Metformin, Pioglitazone, and Silymarin Treatment on Non-Alcoholic Fatty Liver Disease: A Randomized Controlled Pilot Study
4. Effects of a new pharmacological complex (silybin + vitamin-E + phospholipids) on some markers of the metabolic syndrome and of liver fibrosis in patients with hepatic steatosis. Preliminary study.
5. The effect of a silybin-vitamin e-phospholipid complex on nonalcoholic fatty liver disease: a pilot study.
6. Silybin combined with phosphatidylcholine and vitamin E in patients with nonalcoholic fatty liver disease: a randomized controlled trial.