Diet Quality Association with Nonalcoholic Fatty Liver Disease by Cirrhosis Status: The Multiethnic Cohort

BACKGROUND: Epidemiological data on the role of overall dietary patterns in nonalcoholic fatty liver disease (NAFLD) are limited, especially from population-based prospective studies. OBJECTIVES: We investigated the associations between dietary patterns assessed by predefined diet quality indexes (DQIs) and NAFLD risk by cirrhosis status in African Americans, Japanese Americans, Latinos, Native Hawaiians, and whites from the Multiethnic Cohort (MEC). METHODS: A nested case-control analysis was conducted within the MEC. NAFLD cases were identified by linkage to 1999–2016 Medicare claims. Four DQIs—Healthy Eating Index (HEI)-2015, Alternative Healthy Eating Index-2010, alternate Mediterranean diet score, and Dietary Approaches to Stop Hypertension (DASH) score—were calculated from a validated FFQ administered at baseline. Conditional logistic regression was used to estimate the ORs and 95% CIs with adjustment for multiple covariates. RESULTS: Analyses included 2959 NAFLD cases (509 with cirrhosis; 2450 without cirrhosis) and 29,292 matched controls. Higher scores for HEI-2015 (i.e., highest compared with lowest quintile OR: 0.83; 95% CI: 0.73, 0.94; P for trend = 0.002) and DASH (OR: 0.78; 95% CI: 0.69, 0.89; P for trend < 0.001), reflecting favorable adherence to a healthful diet, were inversely associated with NAFLD risk. Whereas there were no differences by sex or race/ethnicity, the inverse association was stronger for NAFLD with cirrhosis than for NAFLD without cirrhosis (P for heterogeneity = 0.03 for HEI-2015 and 0.05 for DASH). CONCLUSIONS: Higher HEI-2015 and DASH scores were inversely associated with NAFLD risk in this ethnically diverse population. The findings suggest that having better diet quality may reduce NAFLD risk with more benefit to NAFLD with cirrhosis.