Breastfeeding and tooth decay
It's normal and common for children to breastfeed to sleep. However, many parents are told that breastfeeding to sleep may affect dental health. Is this something to be concerned about?
Breastfeeding is important
The value of breastfeeding for maternal and child health is significant and widely accepted. The World Health Organization recommends children be breastfed for the first 2 years of life and beyond.
What does the research say?
Two recent systematic reviews of breastfeeding and tooth decay found that breastfeeding up to 12 months protects against tooth decay. However, they also found an increased risk of tooth decay when breastfeeding continued beyond 12 months.
A more recent study (Denenish et al 2020) found that the risk of tooth decay was not linked to breastfeeding beyond 12 months.
Could breastmilk protect against tooth decay?
Some research suggests that breastfeeding may actually protect against tooth decay, while formula may play a role in its development.
Antibodies in breastmilk may help to reduce the growth of bacteria (including Streptococcus mutans, the bacterium that causes tooth decay). Lactoferrin, a protein in breastmilk, actually kills S. mutans.
Some formulas dissolve tooth enamel, significantly reduce pH (make it acidic), support the growth of bacteria and can lead to tooth decay.
Breastfeeding is different to bottle-feeding
There is a vast difference between sucking on a bottle and sucking on the breast. In bottle-feeding the milk is released into the front of the mouth and pools around the teeth. A breastfeeding baby draws the nipple into their mouth and the milk is released into the throat. This causes the baby to swallow.
When a baby falls asleep with a bottle, the teat keeps on slowly leaking any milk left in the bottle, into the baby’s mouth. The breast does not release milk unless actively sucked.
Factors which contribute to tooth decay
Factors other than how a baby feeds may also affect the chances of tooth decay. For example:
- Sugar intake. Frequent exposure to sugar-laden food and drink. Limiting your child’s intake of foods and drinks high in free sugars is important as is having fluoridated tap water as your family’s main drink.
- Streptococcus mutans entering a baby’s mouth. Parents, caregivers, siblings, friends and others can transmit this decay-causing bacterium to the baby without knowing it. This can happen by kissing on the mouth, sharing a toothbrush, drink or spoon with them, or by sucking on their dummy, thinking that this cleans it before putting it back into the child’s mouth. Running it under a tap would be a safer option.
- Lack of saliva. Saliva reduces the risk of tooth decay because it helps to wash sugars from the teeth and also buffers against acids (reduces the acidity). Saliva flow naturally reduces during sleep. Saliva flow is also reduced in asthma, prematurity, diabetes and when using certain medications such as beta 2 agonists (used to treat asthma), antihistamines, benzodiazepines (‘sleeping pills’) and drugs taken for nausea and vomiting.
- Maternal or foetal illness or stress during pregnancy.
- Maternal smoking during pregnancy.
- Poor dietary habits of the family.
- Poor oral and overall hygiene of the family. Regardless of how your baby is fed, it is important to clean their teeth properly once the teeth appear and to have regular dental check-ups.
- Family genetics. In some cases there are enamel defects.
- Other conditions. These include low birth-weight (including prematurity), malnutrition, asthma, recurrent infections and chronic diseases.