Effects of olive oil on hepatic steatosis and liver enzymes: A systematic review

[Display omitted] •Hepatic steatosis is a key histological feature of NAFLD.•Olive oil may help alleviate hepatic steatosis and modulate liver enzyme levels.•Olive oil with higher polyphenols may be superior.•Future studies are recommended to specify olive oil types and polyphenol contents. Hepatic steatosis, a key feature of non-alcoholic fatty liver disease, is prevalent in various conditions such as obesity and type 2 diabetes mellitus. This systematic review aims to evaluate the effectiveness of olive oil on various hepatic health-related indicators. Six randomized controlled trials using olive oil for eating or cooking were included, totaling 344 individuals with a median age of 43 years and a mean baseline body mass index of 29.4, with 57.6% being male. Study durations ranged from 4 weeks to 6 months. In all four studies assessing hepatic steatosis grading through ultrasound, significant reductions were observed in the olive oil groups. Significant decreases in aspartate transaminase and alanine transaminase levels were reported in two studies. In conclusion, olive oil shows promise in ameliorating hepatic steatosis; however, further investigations are warranted to explore the potential effects of different olive oil types or olive polyphenols on chronic liver ailments.