“But I Heard that Prolonged Breastfeeding Causes Tooth Decay…”

breastfeedingFor moms who can breastfeed, the practice comes with a lot of advantages – like the oral health benefits we looked at last week.

According to a study in Pediatric Clinics of North America, “Breastfeeding clearly improves the health of infants and mothers and seems to result in cost savings for parents, insurers, employers, and society, which means that the medical and economic value of breastfeeding is high.”

World Health Organization guidelines recommend breastfeeding for the first 6 months, up to 2 years old.

The systematic review’s findings suggest that exclusive breastfeeding of infants with only breast milk, and no other foods or liquids, for six months has several advantages over exclusive breastfeeding for 3-4 months followed by mixed breastfeeding.

These advantages include a lower risk of gastrointestinal infection for the baby, more rapid maternal weight loss after birth, and delayed return of menstrual periods. No reduced risks of other infections or of allergic diseases have been demonstrated. No adverse effects on growth have been documented with exclusive breastfeeding for six months.

Yet there are those who think that breastfeeding – particularly long-term feeding – can lead to tooth decay. Is there any truth to this?

A new paper in Caries Research clearly says “no.”

The study analyzed data from 556 breastfed children in Khon Kaen, Thailand. Questionnaires on feeding practices were taken periodically over three years. Children who were exclusively breastfed for 6 to 11 months were found to have less decay and fewer teeth with decayed, missing, or filled surfaces.

There was no association between duration of any breastfeeding and dental caries. In conclusion, full breastfeeding for 6-11 months may protect against dental caries in primary teeth. Prolonged breastfeeding was not associated with dental caries in this population. [emphasis added]

One factor that did impact caries? Frequency of sleeping during feeding, whether by breast or bottle. The researchers found that the greater the frequency, the greater the caries risk. But the duration of feeding itself had nothing to do with it.

This builds on earlier research, such as the Dutch study which found “that prolonged demand breast-feeding does not lead to a higher caries prevalence” or the Greek study, which showed that “breastfeeding of the child for more than 40 days may act preventively and inhibit the development of nursing caries in children.”

But what about research that’s found otherwise? Joylyn Fowler offers a good discussion in a New Beginnings article worth quoting at length:

Dr. Joyce Sinton and her colleagues did a comparison of research on feeding methods and dental caries in an attempt to discover why studies disagree about whether breastfeeding contributes to dental caries. Overall, their comparison indicated that many of the studies that showed a link between breastfeeding and caries had contradictory findings and weak methodology. Most of the articles found by the researchers were not included in the final comparison because they were simply “case studies.” This means that they were descriptions of one or more breastfed children who were observed after cavities had already been identified. These studies assumed that the decay was caused by breastfeeding, but offered no proof. The researchers stated that excluding these studies resulted in excluding most of the “classical” articles on the subject.

The remaining studies were carefully compared. One possible source of conflicting results is that the studies often didn’t consider other potential factors in dental caries, such as the fluoridation of water supply or the child’s diet other than breastfeeding. The studies also used imprecise definitions for both “breastfeeding” and for the effectiveness of parents’ dental health practices. For example, babies who were both breastfed and fed formula on a regular basis might be considered breastfed in one study and formula-fed in another study. Confusion about such definitions often gives misleading research results, since exclusive breastfeeding leads to different results than mixed feeding. It’s just plain bad science to use such imprecise definitions.

Finding accurate information about breastfeeding and dental caries is important because early childhood caries are both very common and very expensive to treat. Some researchers assert that early childhood caries are almost epidemic in some populations (Tinanoff and O’Sullivan 1997). Costs per case have been estimated at $700 to $1200 (US) for the dental treatment and $200 to $1500 (US) for medication (Erickson 1999). The costs in stress and trauma for both parents and child are not so easily measured, particularly when there is a sudden weaning involved.

Image by Benjamin Magaña, via Flickr