Original paper

Effects of phytosterol supplementation on serum levels of lipid profiles, liver enzymes, inflammatory markers, adiponectin, and leptin in patients affected by nonalcoholic fatty liver disease: a double-blind, placebo-controlled, randomized clinical trial

  • Non-alcoholic fatty liver disease (NAFLD) is an important global health problem and its prevalence is growing as part of the current obesity epidemic
  • This exploratory study found that a 1.6 g/d supplement of phytosterols (plant sterols or stanols) taken for 8 weeks was effective in lowering LDL cholesterol (LDL-C), elevated liver enzymes and some markers of inflammation
  • This study suggests a benefit of phytosterols for NAFLD patients, but larger and longer-term studies are needed to confirm the results

It is estimated that non-alcoholic fatty liver disease (NAFLD) has an impact on the health of 25-30% of the general population1,2. NAFLD can lead to liver damage such as liver fibrosis and cirrhosis as a result of inflammatory processes from increased fat around the liver.

This exploratory, randomised, double-blind, placebo-controlled clinical  study, set in Iran, investigated the effectiveness of phytosterol supplementation in helping to control disease markers for inflammation and liver damage as well as LDL-C in patients with NAFLD.  Fasting blood samples were taken at baseline and then again at the end of the study at eight weeks. Thirty eight patients (who had been diagnosed by ultrasound with NAFLD) were included and were divided into a control and placebo group. The control group were given a starch tablet as a placebo supplement whilst those in the active arm of the study received an oral supplement of 1.6 g of phytosterols in the form of a daily capsule.

The daily intake of 1.6 g of phytosterol supplementation in patients with NAFLD significantly reduced serum levels of LDL-C, the liver enzymes AST and ALT and the inflammatory marker TNF-a but did not affect other cholesterol measures (e.g. high density lipoprotein, triglycerides, cholesterol ratios), other liver enzymes (GGT), other inflammatory markers (IL-6, hs-CRP) or hormones regulating energy use within the body (leptin) and the formation of fatty deposits in the arteries (adiponectin).

It is assumed that these exploratory findings will lead to further research into the role of phytosterols in the treatment of NAFLD. Of note, this study enrolled a limited numbers of participants and was carried out over just 8 weeks. Larger and longer-term studies are needed.