Breastfeeding and tooth decay

It's normal and common for children to breastfeed to sleep. However, many parents receive advice about breastfeeding to sleep and dental health. Is this something to be concerned about? 

What the research says

Blaming breastfeeding or breastfeeding to sleep for tooth decay is very common. The belief that breastfeeding to sleep causes dental caries is based on only 3 articles by Bram and Maloney1, Gardner, Norwood and Eisenson2 and Kotlow3 that were done in the late 1970s and early 1980s. The authors presented case reports of just nine babies in total, two of whom also received bottles. Case reports have a very low level of scientific evidence; not one of them included any experimentation or trials. The conclusions in these articles were based on this small number of case reports and on the dentists’ own inadequate understanding of breastfeeding.

Later research opposes the notion that breastfeeding has anything to do with tooth decay. This evidence includes population studies which have shown no relationship between breastfeeding and tooth decay in large groups of young children, for example:

 In fact, research suggests that breastfeeding may actually protect against tooth decay, whereas formula may play a role in its development. Antibodies in breastmilk may help to impede bacterial growth (including Streptococcus mutans, which is the bacterium that causes tooth decay). Lactoferrin, a protein in breastmilk, actually kills S. mutans.4,5 Rugg-Gunn and colleagues reported that S. mutans may not be able to use lactose, the sugar found in breastmilk, as readily as sucrose, which is found in some formulas.6 Dr Erickson and her co-workers’ research has demonstrated that some formulas dissolve tooth enamel, significantly reduce pH, support bacterial growth and can lead to tooth decay.7 Ribeiro and Ribeiro’s review article concluded that formula has the potential to cause tooth decay.8

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, whereas in breastfeeding, the nipple is drawn far back into the mouth and the milk is released into the throat, stimulating the baby to swallow. When a baby falls asleep with a bottle, the teat will continue to leak any remaining bottle contents slowly into the baby’s mouth, while the breast will not release milk unless actively sucked.

Did our ancestors suffer tooth decay?

Archaeological studies of the teeth of children in prehistoric times show that very little decay existed, even though it can be assumed that those who survived babyhood would have been breastfed for lengthy periods and probably would have slept with their mothers and breastfed during the night.9,10

Factors which contribute to tooth decay

Factors other than how a baby feeds may also impact the development of tooth decay. For example:

  • Sugar intake. Frequent exposure to sugar-laden food and drink.8
  • Strep mutans entering a baby’s mouth. S. mutans can be transmitted to the baby by way of parents, caregivers, siblings, friends and others.11 They may inadvertently pass on tooth-decay-causing bacteria to the child 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.
  • Salivary disorders. Saliva provides a defence against S. mutans because it helps to wash sugars from the teeth and also provides buffering against acids. Saliva flow naturally reduces during sleep.12 Apart from sleep, saliva flow is also reduced in asthma, prematurity, diabetes and use of certain medications such as beta 2 agonists (used to treat asthma), antihistamines, benzodiazepines and anti-emetics etc.8,13
  • Maternal or foetal illness or stress during pregnancy.8,13
  • Maternal smoking during pregnancy.14
  • Poor dietary habits of the family.8,13
  • Poor oral and overall hygiene of the family.8,13
  • Family genetics — for example the presence of enamel defects.8
  • Other conditions — for example low birth-weight (including prematurity), malnutrition, asthma, recurrent infections and chronic diseases.8

So there is plenty of evidence that rejects the notion that breastfeeding causes tooth decay. Breastmilk alone does not cause tooth decay. Infants who are exclusively breastfed, however, are not immune to decay as a number of other factors may influence a baby’s risk of tooth decay.

Further information which also has links to articles by Dr Brian Palmer, who has done a lot work in this area. 

The Breastfeeding, Information and Research (BIR) division of ABA has a more detailed and fully referenced article Early Childhood Caries (tooth decay) and Breastfeeding(2010). This article can be obtained upon subscription to BIR or for a fee.

To find out more truths about breastfeeding, join the ABA which provides evidence based information and support. Contact the Australian Breastfeeding Association for more information.  


  1. Brams M, Maloney J 1983, ‘Nursing bottle caries’ in breastfed children. J Peds 103(3): 415-416.
  2. GardnerDE, Norwood JR, Eisenson JE 1977, At-will breast feeding and dental caries: four case reports. ASDC Journal of Dentistry for Children 44 (3):186–191.
  3. Kotlow LA 1977, Breast feeding: A cause of dental caries in children. ASDC Journal of Dentistry for Children 44 (3): 192–193.
  4. Arnold R, Cole M, McGhee J 1997, A bactericidal effect for human lactoferrin. Science 197:263–65.
  5. Mandel ID 1996, Caries prevention: current strategies, new directions. JADA 127:1477–88.
  6. Rugg-Gunn A, Roberts GJ, Wright WG 1985, Effect of human milk on plaque pH in situ and enamel dissolution in vitro compared with bovine milk, lactose, and sucrose. Caries Res 19:327–34.
  7. Erickson PR, McClintock KL, Green N, et al 1998, Estimation of the caries-related risk associated with infant formulas. Pediatr Dent 20:395–403.
  8. RibeiroNM, Ribeiro MA 2004, Breastfeeding and early childhood caries: a critical review. Jornal de Pediatria 80(5 Suppl):S199–S210.
  9. Erickson PR, Mazhari E 1999, Investigation of the role of human breast milk in caries development. Pediatr Dent 21:86–90.
  10. Palmer B 1998, The influence of breastfeeding on the development of the oral cavity: a commentary. J Hum Lact14:93–98.
  11. Berkowitz R 1996, Etiology of nursing caries: a microbiologic perspective. Public Health Dent 56:51–4.
  12. Bowen WH 1998, Response to Seow: biological mechanisms of early childhood caries. Community Dent Oral Epidemiol 26(1 Suppl):28–31.
  13. Palmer B 2000, Breastfeeding and infant caries: no connection. ABM News and Views, The Newsletter of The Academy of Breastfeeding Medicine 6(4):27 & 31.
  14. Iida H, Auinger P, Billings RJ, Weitzman M 2007, Association between infant breastfeeding and early childhood caries in the United States. Pediatrics 1(120): e944 -e952.


The information on this website does not replace advice from your health care providers.

 © Australian Breastfeeding Association January 2017

Last reviewed: 
Mar 2017