by Dr. Regina, pediatric dentist

Many mothers get a plethora of well-meaning advice after they have their little ones. One heavily opinionated topic is the debate about whether breastfeeding causes cavities. Some moms will hear about breast milk's protective nature and declare that there is no way that something as natural as breast milk can cause cavities. At the same time, other mothers will tell you all about their neighbor, little Johnny, who had four front teeth pulled at age two because of extended breastfeeding. So, where does science stand right now? Does breastfeeding cause cavities?

What causes cavities?

There are two key elements needed for a cavity to occur:

1. Bacteria: Certain strains of bacteria, primarily Streptococcus Mutans, are responsible for causing cavities. Studies show that babies largely get this bacteria strain from their caregivers via daily activities like saliva exchange when feeding or kissing. In fact, by 6 months of age, 30% of children have the bacteria, and by 30 months of age, 100% of infants have the strain of bacteria necessary to cause cavities.

2. Food Sources: Once the bacteria have colonized your infant’s mouth, they must have a food source to thrive and causes cavities. The bacteria utilize sugars and leftover plaque on teeth to replicate and excrete acid, which causes cavities in the teeth. If the bacteria were deprived of all food sources, they would not function and cause cavities.

Does breast milk cause cavities? 

The composition of breast milk is unique and complex and contains naturally occurring fats, proteins, carbohydrates, and sugars that are crucial for developing an infant.  Studies show that breast milk alone does not cause cavities; however, starting at 6months of age, we begin supplementing a child's diet with complementary foods. Once a child consumes breast milk and additional “table foods,” they start developing plaque on their teeth. This plaque is the perfect substance to activate the bacteria in an infant's mouth, resulting in cavities.

An interesting study showed that when the cavity-causing strain of bacteria, S.mutans, was introduced to teeth placed in breast milk alone, the teeth did not get cavities. In fact, breast milk protected the teeth from cavities. When just a little bit of sugar was introduced, cavities quickly formed. This furthers the point that breast milk alone does NOT cause cavities, but cavities form when coupled with additional sugar sources.

How do I protect my baby from getting cavities while breastfeeding?

The World Health Organization recommends exclusive breastfeeding for up to six months, followed by breastfeeding to complement a well-balanced diet up to a child’s second birthday and beyond.  Granted that a baby's first teeth erupt at around six months of age, this will mean that mothers continue breastfeeding for many months after the eruption of the first teeth.

As a pediatric dentist, there are several steps that I advise patients to take to help protect their infants and toddlers from cavities.

• Leftover food and residue on the teeth are necessary for cavities to form, NOT breast milk alone. Get your little one used to brushing when the first teeth erupt. If you brush away the layer of residual food, it will prevent cavities from forming.

• As per the American Academy of Pediatric Dentistry, begin brushing with a small smear of fluoridated toothpaste in children under age three.

• If your child is still waking up at night to breastfeed after age 1, keep a container of fluoridated mouth rise and some gauze on your nightstand. After your little one breastfeeds, use the soaked gauze to wipe the teeth (especially the front teeth) to prevent cavities.

• Visit a pediatric dentist by age one to discuss the best preventive strategy against plaque formations and cavities.  

Conclusion: Can breastfeeding cause cavities?

The World Health Association supports extended breastfeeding. Fear of dental issues should not deter mothers hoping to achieve their personal breastfeeding goals. Studies show that cavities form due to the introduction of complementary foods, which build up on teeth and cause plaque. Plaque is necessary for cavities to form; thus, keeping your little one's teeth clean is the best preventive measure. See a pediatric dentist by age one and work on a great oral hygiene routine from the start to prevent early childhood cavities. As Dr. Seuss said, “Only brush the teeth you want to keep!”