Abstract

Background and aims: Mechanistic studies and short-term randomised trials suggest higher intakes of dietary flavonoids may protect against non-alcoholic fatty liver disease (NAFLD).

Objective: We aimed to perform the first population-based study with long-term follow-up on flavonoid consumption, incident NAFLD, and validated NAFLD biomarkers.

Methods: In a prospective study, we assessed the associations between flavonoid intake based on ≥2 24-hour dietary assessments and NAFLD risk among 121,064 adults aged 40 to 69 years by multivariable Cox regression analyses. We further assessed the associations between flavonoid intake and MRI-derived liver fat (subset of n = 11,435) and liver-corrected T1 values (cT1, subset of n = 9,570), a marker of steatosis, more sensitive to inflammatory pathology.

Results: Over 10 years of follow-up, 1081 cases of NAFLD were identified. Participants in the highest quartile (Q4) of the Flavodiet Score (FDS) reflecting the consumption of foods high in flavonoids, had a 19% lower risk of NAFLD compared to the lowest quartile (Q1) (HR (95%CI): 0.81 (0.67, 0.97), P trend = 0.02). Moreover, participants in the Q4 of the FDS had a lower liver fat and cT1 values, compared to those in Q1 (liver fat: relative difference Q1 vs Q4: -5.28%, P trend = <0.001; cT1: relative difference Q1 vs Q4: -1.73%, P trend = <0.001). When compared to low intakes, high intakes of apples and tea were associated with lower NAFLD risk (apples: HR (95%CI): 0.78 (0.67, 0.92), P trend = <0.01; tea: HR (95%CI): 0.86 (0.72, 1.02), P trend = 0.03). Additionally, when compared to low intakes, high apple, tea, and dark chocolate intakes were significantly associated with lower liver fat values, while high tea and red pepper intakes were significantly associated with lower cT1 values.

Conclusion: The consumption of flavonoid-rich foods was associated with a reduced risk of NAFLD among middle-aged adults.