Scientists investigating the rise in asthma among Britain’s children have turned to the tooth fairy to help them in their research.
Over the last six years staff at the Children of the 90s project based at the University of Bristol have collected almost 12 thousand milk teeth.
Instead of putting them under the pillow – the children were asked to donate the teeth to the study. Inside the Avon Longitudinal Study of Parents and Children (ALSPAC), real-life tooth fairy Kaija Turvey made sure that every tooth was rewarded with a badge.
Now scientists are using the fact that the children’s two top front teeth – which begin to develop while the babies are still in the womb – contain a detailed record of how well the baby was nourished with trace elements and minerals before birth ...and that could tell them why some children go on to develop wheezing and asthma.
Dr Seif Shaheen of King’s College London suspects that if a baby does not receive enough iron and selenium in the womb this may increase their risk of wheezing in early childhood and possibly asthma later on. If he is right – it could eventually lead to women taking supplements during pregnancy in order to prevent the development of wheezing and asthma in their offspring.
The National Asthma Campaign is funding Dr Shaheen and Dr John Appleton from the University of Liverpool Dental School to analyse the mineral content of the milk teeth of 250 children with asthma and 250 children without asthma.
Dr Appleton says the research project exploits an idea developed in the University of Liverpool going back 10 years. But it has never been used in this way before. “We had the idea that we could monitor an individual’s exposure to various things by examining the teeth – the trace elements become incorporated in hard tissue, particularly teeth
“I’ve done a lot of work to monitor environmental pollution with animal teeth – but this will be the first time we’ve done this in relation to human disease.”
Dr Shaheen says that previous research on umbilical cord samples in the ALSPAC cohort had indicated a possible connection between the level of exposure to iron and selenium before birth and subsequent risk of wheezing… but until now it has been difficult to obtain a totally accurate record of such exposure.
“Milk teeth begin to develop before birth and the enamel takes up trace elements and minerals, thus capturing a permanent record of exposure. When milk teeth drop out the enamel can be analysed to look back in time and tell us about a baby’s actual level of exposure to trace elements and minerals before birth.
“A lot of chronic diseases have their origins before birth, in the womb. Clues are emerging to suggest that factors which influence the development of the lung and immune system of a baby in the womb are likely to play an important part in determining whether they subsequently suffer from wheezing and asthma as children.
“We have preliminary evidence to suggest that babies exposed to higher levels of selenium in utero have a lower risk of persistent wheezing in early childhood, and those exposed to higher levels of iron have a lower risk of later onset wheezing and eczema.
In the UK, intakes of selenium have been falling at the same time as asthma has been increasing. Selenium occurs naturally in fish, meat, cereals and dairy products – but the richest source is Brazil nuts.
Philippa Major, National Asthma Campaign's assistant director of research said: "Asthma is the most common long term condition in the UK today.
“One of our most urgent research priorities is to address the primary prevention of asthma in children. We are excited and pleased to be funding this ground-breaking research which will help us to identify what causes asthma to develop in children."
ends
Notes to editors
Human upper central deciduous incisors (the first to fall out, at about six years of age) begin to calcify between 14 and 19 weeks in utero and finish at about 8-12 weeks after birth. Tooth enamel therefore encapsulates a permanent record of prenatal and very early postnatal exposure to trace elements and minerals.
ALSPAC The Avon Longitudinal Study of Parents and Children (also known as Children of the 90s) is a unique ongoing research project based in the University of Bristol. It enrolled 14,541 mothers during pregnancy in 1991-2 and has followed the children and parents in minute detail ever since. At the last count Kaija had 11,921 teeth – and has stopped asking children to send them in.
The National Asthma Campaign is the independent UK charity dedicated to conquering asthma. It funds asthma research, offers help and advice and campaigns for a better deal for people with asthma.
Living with asthma raises all sorts of questions and concerns. Call the Asthma Helpline for help and advice from asthma nurses on 0845 7 01 02 03.from 9am to 5pm.
The National Asthma Campaign website is at http://www.asthma.org.uk
Dr Seif Shaheen is a senior lecturer in epidemiology at King’s College, London. Email: seif.shaheen@kcl.ac.uk
Dr. John Appleton is a senior lecturer in the Department of Clinical Dental Sciences, University of Liverpool. E-mail: app@liv.ac.uk