Intake of the different types of dairy products, genetic predisposition, and the risks of nonalcoholic fatty liver disease and cirrhosis: a prospective cohort study

Abstract

Background: The association of dairy product consumption with nonalcoholic fatty liver disease (NAFLD) and cirrhosis remains controversial. This study aimed to prospectively investigate the associations between the consumption of the different types of dairy products, genetic predisposition, and the risks of NAFLD and cirrhosis. Methods: This cohort study included 190 145 participants from the UK Biobank Study. The consumption of the different types of dairy products was assessed based on the Oxford WebQ at baseline and defined as the sum of milk, yogurt, and cheese. NAFLD and cirrhosis were evaluated using hospital inpatient records and death data in the UK Biobank. The weighted genetic risk score (GRS) for NAFLD and cirrhosis was constructed using 5 and 6 single-nucleotide variants (SNVs), respectively. Cox proportional hazards regression models were utilized to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between genetic factors and different types of dairy products with the incidence of NAFLD and cirrhosis. Results: During a median follow-up of 11.6 years, 1512 NAFLD and 556 cirrhosis cases were ascertained. After adjusting for several potential confounders, the HRs (95% CIs) (Q4 vs. Q1) of NAFLD were 0.86 (0.74, 0.995) for total dairy products, 0.96 (0.84, 1.09) for high-fat dairy products, 0.78 (0.67, 0.92) for low-fat dairy products, 0.86 (0.74, 0.99) for unfermented dairy products, and 0.79 (0.68, 0.91) for fermented dairy products. The multivariable-adjusted HRs (95% CIs) (Q4 vs. Q1) of cirrhosis were 0.75 (0.59, 0.96) for total dairy products, 0.97 (0.78, 1.19) for high-fat dairy products, 0.67 (0.51, 0.89) for low-fat dairy products, 0.75 (0.59, 0.96) for unfermented dairy products, and 0.71 (0.56, 0.90) for fermented dairy products. The associations of high-fat dairy products and fermented dairy products with NAFLD and cirrhosis were found to be nonlinear (P for nonlinear <0.05). No interaction was observed between dairy product consumption and NAFLD or cirrhosis genetic susceptibility. Conclusions: Higher consumption of dairy products, except for high-fat dairy, was correlated with lower risks of NAFLD and cirrhosis, regardless of their differences in genetic susceptibility.