Background: Green tea is one of the most popular beverages in the world. It is believed to have beneficial effects in the prevention and treatment of many diseases, one of which is nonalcoholic fatty liver disease (NAFLD). The present study investigated the effects of consumption of green tea in NAFLD patients.
Methods: This study was a double-blind, placebo-controlled, randomized clinical trial. Ultrasonography was used to diagnose fatty liver in patients with alanine aminotransferase (ALT) >31 mg/dl and 41 mg/dl and aspartate aminotransferase (AST) >31 mg/dl and 47 g/dl in women and men, respectively and without other hepatic diseases. A total of 80 participants (20-50 years) with NAFLD were randomly allocated into two groups to receive either green tea extract (GTE) supplement (500 mg GTE tablet per day) or placebo for 90 days. At baseline and at the end of the intervention weight, serum ALT, AST, and alkaline phosphatase (ALP) were measured in fasting state, and dietary data were collected at baseline and end of the study.
Results: Green tea group showed significant reductions in ALT and AST levels after 12 weeks period (P < 0.001). The placebo group showed a reduction in ALT and AST levels at the end of the study, but it was no significant. ALP levels showed significant reductions in both groups after 12 weeks period (P < 0.001).
Conclusions: According to the findings of this study, GTE supplementation decrease liver enzymes in patients with NAFLD. It can be claimed that GTE prescribed can be considered as a treatment to improve serum levels of liver enzymes in NAFLD patients.
Keywords: Alanine aminotransferase; alkaline phosphatase; aspartate aminotransferase; green tea extract; nonalcoholic fatty liver disease.