Dairy product consumption and risk of non-alcoholic fatty liver disease: A systematic review and meta-analysis of observational studies

Background and aims It is unclear whether regular consumption of dairy products is associated with the risk of developing non-alcoholic fatty liver disease (NAFLD). Thus, we conducted a systematic review followed by a meta-analysis of studies reporting on the association of dairy consumption with NAFLD risk. Methods and results We comprehensively searched PubMed, Web of Science, and Scopus for observational studies that evaluated the association between dairy intake and NAFLD likelihood that were published before September 1, 2022. The reported odds ratios (ORs) of fully adjusted models and their 95% confidence intervals (CIs) were pooled using a random-effects model for the meta-analysis. Out of 1206 articles retrieved, 11 observational studies, including 43,649 participants and 11,020 cases, were included. Pooled OR indicated a significant association between dairy intake and NAFLD (OR = 0.90; 95% CI: 0.83, 0.98; I2 = 67.8%, n = 11). Pooled ORs revealed that milk (OR: 0.86; 95% CI: 0.78, 0.95; I2 = 65.7%, n = 6), yogurt (OR: 0.88; 95% CI: 0.82; I2 = 0.0%, n = 4), and high-fat dairy (OR: 0.38; 95% CI: 0.19, 0.75; I2 = 0.0%, n = 5) consumption was inversely associated with NAFLD while cheese was not linked to NAFLD risk. Conclusion We observed that consumption of dairy products is linked to a reduced risk of developing NAFLD. Overall, the data in the source articles is of low to moderate quality; therefore, further observational studies are required to support the current findings (PROSPERO Reg. number: CRD42022319028).