Breastfeeding and teeth

Dr Mark Porter on Radio 4’s Inside Health last week had an interesting piece where a particular type of dental problem in children was attributed to extended breastfeeding.

Molar incisor hypomineralisation is described by Professor Monty Duggal, Head of Paediatric Dentistry at the Leeds Dental Institute as “pain and sensitivity in their back molars and also unsightly marks on [children’s] upper front teeth.” This appears to be a relatively new phenomenon, occurring in the last 15 years, and reportedly affects up to 16% of children in the north of England.

Importantly, Professor Duggal explains that this is a perinatal event; that is, something that happens around birth. He then goes on to suggest that new Swedish studies show a link with extended breastfeeding without introduction of solids. He defines extended breastfeeding as breastfeeding beyond six months, which of course is outside the perinatal period.

This raises a few questions for me. We know that in the UK, 23% of babies are still breastfed at six months, but fewer than 2% are exclusively breastfed. Current Department of Health guidelines are to introduce solids at around six months, and the vast majority of parents do it before this time. So I was curious to know where a large enough sample of babies who were exclusively breastfed beyond six months could be found, which perhaps is possible in Sweden where breastfeeding rates are higher, but even so that’s hard to tie up with the stated 16% Molar-incisor hypomineralisation figure for the UK. The Professor’s recommendation to introduce some solids by six months is hardly ground-breaking, but my concern would be that “by six months” would make parents feel they need to start earlier than that, which is not supported by the Department of Health.

With no reference to the Swedish study, it has been hard to follow this up; but I have found an interesting webpage that collates 40 studies of Molar-incisor hypomineralisation from different countries. Without PubMed access, I can only read the abstracts, but few of them mention breastfeeding at all, and this one from 2008 explicitly finds no link with breastfeeding. A 2012 study co-authored by Duggal doesn’t mention breastfeeding in the abstract, but does find a link with lower socio-economic status. Which is interesting in that we also know lower socio-economic status is correlated with shorter duration of breastfeeding. These figures don’t stack up.

On the basis of this interview and my subsequent reading, I cannot see a basis for Duggal’s claim that “they’re nutritionally not fully supported” in the context of dental issues; however it is well-established that breastmilk is a nutritionally complete diet until around the age of six months, when complementary foods are usually needed.

Finally I discovered that Dr Mark Porter is heavily involved with baby milk manufacturer Cow & Gate. Some cynics might feel that such a vested interest in not breastfeeding should be declared whenever there is an article about breastfeeding on the show.