Comparison of viscosities of human breast milk versus infant milk formulae with and without addition of sweetening agents.

Context: Early childhood caries is a major health problem affecting children worldwide. Although incorrect feeding practices hold a prime position in the etiology, there are gaps in the literature pertaining to the physical properties of milk.

Aim: To assess the viscosity of human breast milk (HBM) versus infant milk formulae, with and without the addition of sweetening agents.

Materials and methods: All commercially available infant milk formulae (60 samples) and breast milk from 30 donor mothers were assessed for viscosity using Brookfield DV2T viscometer. The study period was from April 2019 to August 2019. Viscosity of infant milk formulae sweetened with sugar, honey, and brown sugar was further investigated and compared with that of HBM.

Statistical analysis: Inter-group and intra-group mean viscosity was compared using independent t-test and repeated-measures ANOVA.

Results: Viscosity of HBM ranged from 18.36 centipoise (cP) to 91.30 cP, the mean viscosity being 45.7 cP. Viscosity values varied for each formula group, the least being as low as 5.1 cP and the highest being 89.3 cP. The mean viscosities of each group were in the range of 33 to 49 cP.

Conclusions: HBM was found to have a tendency toward higher viscosity than most of the infant milk formulae. Also, varied viscosity values were obtained when commonly used sweetening agents were added to infant milk formulae. Greater viscosity of HBM might increase its adherence to enamel surface leading to prolonged demineralization and potentially altering the caries risk, needs to be investigated further.