The Association Between Breastfeeding and Nonalcoholic Fatty Liver Disease in Parous Women: A Nation-wide Cohort Study

Background and Aims: Breastfeeding has multiple effects on maternal health outcomes. However, the effect of breastfeeding on NAFLD in parous women remains unclear. Approach and Results: A total of 6,893 Korean parous women aged 30-50 years who participated in the Korean National Health and Nutrition Examination Survey were assessed for the association between breastfeeding and NAFLD. Duration of lactation was calculated by dividing the total lactation period by the number of breastfed children. NAFLD was defined by the hepatic steatosis index. Of 6,893 women, 1,049 (15.2%) had NAFLD. Prevalence of NAFLD was 18.3%, 14.3%, 12.3%, 14.4%, and 15.8% in women with a breastfeeding period of <1, ≥1-<3, ≥3-<6, ≥6-<12, and ≥12 months, respectively. In a fully adjusted model, breastfeeding (≥1 month) was associated with reduced NAFLD prevalence (OR, 0.67; 95% CI, 0.51-0.89) after adjusting for metabolic, socioeconomic, and maternal risk factors. Fully adjusted ORs (95% CI) decreased with an increase of breastfeeding duration: 0.74 (0.49-1.11), 0.70 (0.47-1.05), 0.67 (0.48-0.94), and 0.64 (0.46-0.89) for women with ≥1-<3, ≥3-<6, ≥6-<12, and ≥12 months of breastfeeding duration, respectively, compared to women with <1 month of breastfeeding duration. Such an association was also observed in all predefined subgroups without interaction. Conclusions: Breastfeeding showed a protective effect against NAFLD in later life of parous women, suggesting a maternal benefit of breastfeeding on NAFLD.