Dietary antioxidant capacity, flavonoid subclasses, and metabolic dysfunction-associated fatty liver disease in overweight and obese youth.

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a growing public health concern among children and adolescents with overweight and obesity. Diet quality, particularly antioxidant intake, may play a role in hepatic metabolic regulation. This study investigated the association between dietary total antioxidant capacity (DTAC) and MAFLD, and examined the mediating role of flavonoid subclasses.

METHODS

In this cross-sectional study, 505 overweight and obese Iranian children and adolescents aged 7-18 years were recruited. DTAC was estimated using a validated 147-item food frequency questionnaire and the ferric reducing antioxidant power (FRAP) method. MAFLD was diagnosed via ultrasonographic evidence of hepatic steatosis in combination with overweight/obesity. Logistic regression and restricted cubic spline models assessed associations, and mediation analysis evaluated indirect effects of flavonoids.

RESULTS

The mean DTAC was 8.7 ± 3.8 overall, 8.3 ± 3.3 in the MAFLD group, and 9.0 ± 4.1 in the non-MAFLD group. In fully adjusted model, participants in the highest DTAC tertile had 62% reduced odds of MAFLD compared to the lowest tertile (OR: 0.38; 95% CI: 0.18-0.82; P-trend = 0.03). Spline analysis confirmed a non-linear inverse association. Mediation analysis revealed that flavonols and anthocyanidins significantly mediated the DTAC-MAFLD relationship, accounting for 74.4% and 38.4% of the total effect, respectively.

CONCLUSION

Higher dietary antioxidant capacity is inversely associated with MAFLD in overweight and obese youth, partly through the intake of specific flavonoid subclasses. These findings emphasize the value of antioxidant-rich diets for pediatric liver health and highlight the need for longitudinal studies or clinical trials to confirm causal relationships.