A longitudinal study on the impact of breastfeeding with or without formula milk on dental caries

Abstract

Abstract Concerns exist about prolonged breastfeeding increasing dental caries risk, but evidence is mixed. This 2-year cohort study followed 486 toddlers, to examine the association between breastfeeding duration and caries at age 3. Caregivers reported feeding practices and potential confounders every 6 months. “Full breastfeeding” was defined as feeding breastmilk without formula milk regardless of other foods/liquids, whereas “any breastfeeding” was feeding breastmilk with/without formula milk. A calibrated dentist performed dental examinations. We used multivariable log-binomial and negative binomial regressions to estimate relative risks (RRs) and 95% confidence intervals (CIs) for caries prevalence and severity, adjusted for confounders. At 3-year-old, 60.3% of children exhibited caries (mean decayed-and-filled-teeth, dft: 3.3). Notably, full breastfeeding for 6–17 months reduced caries prevalence (RR = 0.84, 95%CI 0.73–0.98 for 6–11 months; RR = 0.78, 95%CI 0.63–0.96 for 12–17 months). Conversely, any breastfeeding ≥ 18 months significantly increased caries risk (RR = 1.45, 95%CI 1.31–1.60). Full breastfeeding ≥ 6 months or any breastfeeding 6–17 months was associated with lower dft scores in children. Our findings suggest a complex relationship between breastfeeding duration and caries. Full breastfeeding for moderate durations (6–17 months) offers protective benefits, while any breastfeeding ≥ 18 months increases risk in this population.