The effect of coffee consumption on the non-alcoholic fatty liver disease and liver fibrosis: A meta-analysis of 11 epidemiological studies

Abstract

Introduction and objectives: Non-alcoholic fatty liver disease (NAFLD) is a widespread chronic liver disease. It is considered a multifactorial disorder that can progress to liver fibrosis and cause a worldwide public health concern. Coffee consumption may have a protective impact on NAFLD and liver fibrosis. However, the evidence from the previous studies is inconsistent. This meta-analysis summarizes available literature. Materials and methods: This study comprises two meta-analyses. The first meta-analysis summarizes the effect of coffee consumption on NAFLD in those who did or did not drink coffee. The second analysis compares the risk of liver fibrosis development between NAFLD patients who did or did not drink coffee. Pooled risk ratios (RR) and confidence intervals (CI) of observational studies were estimated. Results: Of the total collected 321 articles, 11 met our eligibility criteria to be included in the analysis. The risk of NAFLD among those who drank coffee compared to those who did not was significantly lower with a pooled RR value of 0.77 (95% CI 0.60–0.98). Moreover, we also found a significantly reduced risk of liver fibrosis in those who drink coffee than those who did not drink in the NAFLD patients with the relative risk (RR) of 0.68 (95% CI 0.68–0.79). Conclusions: Regular coffee consumption is significantly associated with a reduced risk of NAFLD. It is also significantly associated with decreased risk of liver fibrosis development in already diagnosed NAFLD patients. Although coffee consumption may be considered an essential preventive measure for NAFLD, this subject needs further epidemiological studies.

Keywords

• NAFLD (non-alcoholic fatty liver disease)
• NASH (Non-alcoholic steatohepatitis)
• Confidence interval
• Relative risk
• Coffee
• Caffeine