Early childhood caries and its associations with sugar consumption, overweight and exclusive breastfeeding in low, middle and high-income countries: an ecological study

AIM: This ecological study examined the associations between the prevalence of early childhood caries (ECC), overweight, country’s per capita sugar consumption and duration of exclusive breastfeeding. METHODS: Per capita consumption of sugar in kilograms, percentage of children exclusively breastfed until 6 months of age, percentage of 0–5-year-old children with overweight status, and percentage of 3–5-year-old children with ECC were compared among low-income countries (LICs), middle-income countries (MICs) and high-income countries (HICs). The association between the prevalence of ECC and the study variables, and the effect modification by income region were assessed using multivariable linear regression models. Regression coefficients, confidence intervals, partial eta squared and P-values for effect modification were calculated. RESULTS: The per capita sugar consumption in LICs was significantly lower than in MICs (P = 0.001) and HICs (P < 0.001). The percentage of infants who exclusively breastfed up to 6 months was significantly lower in HICs than in LICs (P < 0.001) and MICs (P = 0.003). The prevalence of overweight was significantly lower in LICs than in MICs (P < 0.001) and HICs (P = 0.021). The prevalence of ECC was significantly lower in HICs than in MICs (P < 0.001). Income was a significant modifier of the associations between the prevalence of ECC, per capita sugar consumption (P = 0.005), and exclusive breastfeeding up to 6 months (P = 0.03). The associations between the prevalence of ECC and per capita sugar consumption at the global level and for MICs were stronger (partial eta squared = 0.05 and 0.13 respectively) than for LICs and HICs (partial eta squared <0.0001 and 0.003 respectively). Only in MICs was there a significant association between the prevalence of ECC and per capita sugar consumption (P = 0.002), and between the prevalence of ECC and the percentage of children exclusively breastfed up to 6 months (P = 0.02). CONCLUSION: Though the quantity of sugar consumption and exclusive breastfeeding may be a significant risk indicator for ECC in MICs, sugar consumption may be more of a risk indicator for ECC in HICs than in LICs, and vice versa for exclusive breastfeeding. Although ECC and overweight are both sugar-related diseases, we found no significant relationship between them.