Does a high intake of green leafy vegetables protect from NAFLD? Evidence from a large population study

Abstract

Background and aims: Results of in vitro and in vivo studies showed that green leafy vegetables (GLV) could attenuate liver steatosis. However, little is known regarding the association between GLV intake and nonalcoholic fatty liver disease (NAFLD) in human. We examined the association of GLV intake with NAFLD in a large-scale adult population.

Methods and results: This cross-sectional study investigated 26,891 adults in China who participated in health examinations from 2013 to 2017. Newly diagnosed NAFLD was detected by liver ultrasonography. Dietary intake was assessed by using a validated and standardized food frequency questionnaire. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) across categories of GLV intake. After adjustment for sociodemographic characteristics, lifestyle factors, and other dietary intakes, the OR (95% CI) for comparing the highest vs. lowest GLV intake categories (≥7 times/week vs. almost never) was 0.72 (0.59, 0.90) (P < 0.0001). In addition, a linear inverse association was demonstrated between GLV intake and NAFLD in women (P for trend = 0.04), but ORs for any intake category did not reach significance. Stratified analyses suggested a potential effect modification by obesity status; the ORs (95% CIs) for comparing the highest vs. lowest GLV intake categories was 0.72 (0.54, 0.97) in normal/overweight individuals and 1.04 (0.65, 1.65) in obese individuals (P-interaction < 0.0001).

Conclusion: This large population-based study shows that high GLV intake is inversely associated with NAFLD, particularly in women and non-obese participants.

Keywords: Green leafy vegetables; Nonalcoholic fatty liver; Obesity; Population-based study.