“August is National and World Breastfeeding Awareness Month, and experts and mothers from more than 170 countries agree: Breast milk is best when it comes to feeding a baby in the first year of life. Like trees, teeth contain growth rings that can be counted to estimate age. Teeth rings also incorporate dietary minerals as they grow. Breast milk contains barium, which accumulates steadily in an infant’s teeth and then drops off after weaning.”

NIH – National Institute of Health