Tea and coffee consumption impact on the non-alcoholic fatty liver disease: a systematic review and meta-analysis

 Non-alcoholic fatty liver disease (NAFLD) is diagnosed when≥5–10% of hepatocytes display macroscopic steatosis in the absence of other etiologies of liver disease. Consumption of coffee or tea or both may decrease the risk of NAFLD, as recommended by studies of liver enzymes.

 The required data was collected from different databases such as EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and Web of Science as well as the database inception to July 2021. In addition, pooled mean difference and 95% confidence intervals (CIs) were considered in the random effects model.

 Of the total collected 218 articles, 8 met our inclusion criteria to be involved in the meta-analysis. Four studies assessed green tea and one study assessed sour tea consumption in NAFLD patients. Three studies assessed coffee use. All studies have shown an inverse correlation of coffee intake with elevated serum enzyme levels. Based on the meta-analysis outcome, the mean alanine aminotransferase (ALT) in the intervention group was measured as 12.50 points less than that of the control group. The mean aspartate aminotransferase (AST) of the intervention group was 9.23 points lower than that of the control group (P value<0.001).

 There is increasing evidence that steadily revealed an opposite relationship between the consumption amount of green tea and coffee and the risk of liver diseases. This meta-analysis supports the protective role of the mentioned beverages in patients suffering from NAFLD.