Higher ultra-processed food intake is associated with adverse liver outcomes: a prospective cohort study of UK Biobank participants.

BACKGROUND: Ultra-processed food (UPF) intake has been positively associated with obesity and diabetes. The relationship between UPF intake and liver health has been scarcely studied. OBJECTIVES: We aimed to evaluate the association of UPF intake with risk of adverse liver outcomes including nonalcoholic fatty liver disease (NAFLD), liver fibrosis/cirrhosis, liver cancer, severe liver disease, and serum biomarkers of liver health. METHODS: A total of 173,889 participants aged 40 to 69 y from the UK Biobank were included. UPF intake was defined using 24-h dietary recalls and NOVA classification. Liver outcome data were obtained from cancer registry, in-hospital records, and death registries. Serum biomarkers were measured at baseline. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between UPF and adverse liver outcomes adjusting for demographics, lifestyle factors, body mass index, and diabetes. We used multinomial logistic regression to evaluate associations between UPF and liver function biomarkers. RESULTS: After a median follow-up of 8.9 y, we documented 1108 NAFLD, 350 liver fibrosis/cirrhosis, 134 liver cancer, and 550 severe liver disease cases. Higher UPF intake was associated with increased risk of NAFLD (HRQuartile 4 vs. Quartile 1: 1.43; 95% CI: 1.21, 1.70; Ptrend < 0.001), liver fibrosis/cirrhosis (HR: 1.18; 95% CI: 0.87, 1.59; Ptrend = 0.009), and severe liver disease (HR: 1.50; 95% CI: 1.19, 1.90; Ptrend < 0.001) but not with liver cancer (HR: 1.00; 95% CI: 0.63, 1.58; Ptrend = 0.88). Higher UPF intake was associated with elevated levels of C-reactive protein, alkaline phosphatase, aspartate aminotransferase, γ-glutamyltransferase, and triglycerides and lower cholesterols (all Ptrend < 0.001). CONCLUSIONS: Higher UPF intake is associated with an increased risk of NAFLD, liver fibrosis and cirrhosis, and severe liver disease and adverse levels of multiple clinical biomarkers, suggesting the potential importance of reducing UPF intake to improve liver health.