Breastfeeding and Tooth Decay

Sometimes a parent will notice their toddler’s tiny new teeth are marked or have cavities. Parents naturally worry about what could have caused these and how to prevent further damage. There are several possible causes of early cavities but a favourite scapegoat amongst some dentists is to blame breastmilk and breastfeeding; especially breastfeeding during the night. Once breastfeeding has been blamed for cavities; a mother often feels pressured to stop breastfeeding yet she also knows that breastfeeding has so many advantages for her baby’s health.

Does breastfeeding cause early tooth decay?

No, it is biologically normal to breastfeed long after teeth arrive and for as long as mother and baby want. This article looks at how breastfeeding helps shape a baby’s mouth and airways, how research studies do not find a link between breastfeeding and tooth decay, historic reasons why breastfeeding is blamed, and alternative causes of early tooth decay.

Breastfeeding shapes the mouth and teeth

Breastfeeding is important for babies and toddlers for many health reasons and these are already covered in several locations online including UNICEF and LLLI. Dentist and researcher Dr Brian Palmer DDS also described less well known advantages of breastfeeding such as normal palate formation, optimal teeth alignment and how the correct action of the tongue during swallowing is critical to the proper development of the mouth (oral cavity), airway shape, and facial form. These factors can help to reduce SIDS, sleep apnea, the need for orthodontics and can promote other future health benefits. With so many potential benefits to an infant, it would seem illogical that breastfeeding also be detrimental to his health. What does research say about breastfeeding causing tooth decay?

Is there any research on breastfeeding and tooth decay?

Yes, a couple of studies in 2007 looked at tooth decay in breastfed children and did not find any evidence that breastfeeding was a cause.

#1. Kraer et al

A large randomised trial by Kraer et al in 2007 followed 13,889 mother baby breastfeeding pairs but did not establish a link between breastfeeding past the baby stage with tooth decay at age six years:

Our results, based on the largest randomized trial ever conducted in the area of human lactation, provide no evidence of beneficial or harmful effects of prolonged and exclusive breastfeeding on dental caries at early school age.

#2. Lida et al

Another study in the United States in 2007 by Hiroko Lida et al, 20071 failed to find a link between breastfeeding or its duration with early childhood caries, or severe early childhood caries on primary teeth. It did however highlight other risk factors (see below).

Why do dentists blame breastfeeding?

If there is no compelling evidence, why do some dentists blame breastfeeding for early tooth decay? Dr Jack Newman, Canadian paediatrician and breastfeeding expert, has his own theory as follows:

What dentists don’t see is that the vast majority of children who are nursed during the night do not get cavities. Since those who do end up at the dentist’s office, the doctor often concludes that this is a common problem for children nursing past the first year of life. It isn’t. Even if the child is brought to the dentist for a routine check, the dentist will not usually ask about night nursing unless the child has cavities. Most dentists probably have no idea that some or even many of their cavity-free 18-month old patients are still breastfeeding at night.

Historic reasons

An article from the Australian Breastfeeding Association discusses the historical reasons why some dentists blame breastfeeding as a cause of early childhood cavities;

The belief that breastfeeding to sleep causes dental caries is based on only three articles by Bram and Maloney, Gardner, Norwood and Eisenson and Kotlow 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.

Prehistoric infant skulls did not have any dental decay

One area of Dr Brian Palmer’s research investigated the link between tooth decay and breastfeeding in both historical times and present day and found prehistoric infant skulls did not have any dental decay.

  • If breastmilk caused decay – evolution would have selected against it.
  • It would be evolutionary suicide for breastmilk to cause decay.

If infant tooth decay is a relatively recent problem, yet breastmilk has not changed its mode of manufacture since historical times, what else could be causing early cavities?


Causes of tooth decay

Some risk factors for tooth decay or Early Childhood Caries (ECC) in infants are listed below; based on two presentations on Dr Brian Palmer’s website.2

  • How often a child eats sugary food, including juices, cereals, breads, dried fruit, sweetened medicines
  • Presence of Streptococcus mutans (a bacteria) in the mouth. Infection by Strep mutans from adults’ kisses and sharing spoons, dummies etc can give rise to levels of bacteria capable of causing disease when they are combined with a sugary diet. This in turn can cause rapid demineralization of enamel3 leading to dental decay.4
  • Lack of saliva flow (dry mouth). Saliva is the first line of defence to wash away food and bacteria but saliva flow is reduced during sleep and with certain medical conditions and medications.
  • Stress to the mother or foetus during pregnancy
  • A poor diet – for example eating frequent acidic food and drinks as well as sugars and carbohydrates.
  • Not cleaning teeth properly
  • Enamel defects eg enamel hypoplasia5 or physical injury to enamel
  • Genetics

Dentist Dr Patrick (Harry) Torney found in his unpublished thesis6 that the following factors during the mother’s pregnancy were associated with a high rate of tooth decay for the child:

  • Maternal bereavement or stress
  • Reduced intake of dairy products
  • Medically diagnosed illness of mother
  • Taking of antibiotics by mother.

While other studies have linked further risk factors as

  • Poverty, Mexican American ethnic status, and maternal smoking during pregnancy 7)
  • Low birth-weight (including premature births), malnutrition, asthma, recurrent infections, chronic diseases and medication use alongside infection caused by Strep mutans, enamel hypoplasia, intake of sugars and social conditions 8).

Another possible cause of marked teeth could be fluorosis (mottling of tooth enamel due to too much fluoride) see Tooth Decay in Toddlers for further reading.

What about the sugar in breastmilk?

The sugar in breastmilk is lactose but as this is accompanied by the antibacterial properties, enzymes and high pH levels in breastmilk it is not thought to have the same effect on teeth as pure sugar9. For example Strep mutans (bacteria causing cavities) is highly susceptible to the bactericidal action of lactoferrin10. In one study, milk was shown to actually remineralise11 artificially demineralised enamel in vitro 12.

Formula milk and teeth?

In contrast to the protective effects of breastmilk; a study by Pamela Erickson, DDS, Ph.D. et al 13 looked at the effects of formula on enamel and found most artificial baby milks reduced the pH (acidity) significantly, supported significant bacterial growth and dissolved enamel and some caused decay in a matter of weeks.

How milk is delivered

The techniques of breastfeeding and bottle-feeding are quite different and it seems that bottle-feeding has more potential to cause dental decay; particularly if drinks other than milk such as fruit juices or squash drinks are added to the bottle. This is another source of confusion for dentists who may think breastfeeding breastmilk involves the same risk to teeth as bottle-feeding formula. It doesn’t.

The mechanics of breastfeeding make it unlikely for human milk to stay in the baby’s mouth for long. During breastfeeding, the nipple is drawn deep within the baby’s mouth, and milk is literally squirted into the back of his mouth. The suckling process includes a swallow and the nursing child must swallow before he can go on to the next step. In contrast, baby bottles can drip milk, juice, or formula into the baby’s mouth even if he is not actively sucking. If the baby does not swallow, the liquid can pool in the front of the mouth around the teeth. The artificial nipple is very short, so the liquid in the bottle is likely to pass over teeth before being swallowed.

Protecting little teeth

There does not seem to be any evidence that stopping breastfeeding will prevent or stop dental decay but it is still very important to keep teeth clean and minimise all the other risk factors. For ideas to help protect your children’s teeth see the article Tooth Decay in Toddlers.

cleaning teeth

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