Exposure to air pollution in pregnancy does not increase symptoms of attention-deficit
June 25, 2018
Science Daily/Barcelona Institute for Global Health (ISGlobal)
A study of 30,000 children from seven European countries found no association between prenatal exposure to air pollution and symptoms of attention-deficit and hyperactivity.
Exposure to air pollution during pregnancy may not be associated with an increased risk of attention-deficit and hyperactivity symptoms in children aged 3 to 10 years. This was the conclusion of a new study led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by the "la Caixa" Banking Foundation. The study included data on nearly 30,000 children from seven European countries.
With a worldwide prevalence of 5%, ADHD is the most common childhood behavioural disorder. ADHD is characterized by a pattern of inattention, hyperactivity and/or impulsivity that is atypical for the child's age. These symptoms can interfere with development and have been associated with academic problems in school-aged children as well as an increased risk of problems with addiction or risky behaviours.
Recent studies have concluded that prenatal exposure to air pollution could affect brain development in children, but the evidence on the effects of air pollution on ADHD symptoms is limited.
The new study, published in the journal Epidemiology, forms part of the European Study of Cohorts for Air Pollution Effects (ESCAPE). It included 30,000 children between 3 and 10 years of age from eight birth cohorts in Germany, Denmark, France, Italy, the Netherlands, Sweden and Spain (the latter consisting of four sub-cohorts from the INMA project in Gipuzkoa, Granada, Sabadell and Valencia). The study estimated exposures to nitrogen oxides (NOx) and particulate matter (PM10 and PM2.5) throughout pregnancy at each participant's home address. ADHD symptoms were assessed using various questionnaires completed by parents and/or teachers.
Joan Forns, lead author of the study, commented: "Our findings show no association between exposure to air pollution during pregnancy and increased risk of ADHD symptoms."
"Given the conclusions of this study and the inconsistent findings of previous studies, we hypothesise that exposure to air pollution might not increase the risk of ADHD in children in the general population," explained ISGlobal researcher Mònica Guxens, who coordinated the study. "However, we believe that exposure to air pollution could have harmful effects on neuropsychological development, especially in genetically susceptible children."
It has been shown that ADHD is the result of complex interactions between genetic background (heritability is approximately 75%), environmental factors and social determinants. "We will continue to study the role of air pollution in order to rule out its association with childhood ADHD and improve our understanding of what causes this disorder," said Guxens.
https://www.sciencedaily.com/releases/2018/06/180625122348.htm
Unhealthy diet during pregnancy could be linked to ADHD
August 18, 2016
Science Daily/King's College London
A high-fat, high-sugar diet during pregnancy may be linked to symptoms of ADHD in children who show conduct problems early in life, new research indicates.
Published in the Journal of Child Psychology and Psychiatry, this study is the first to indicate that epigenetic changes evident at birth may explain the link between unhealthy diet, conduct problems and ADHD.
Early onset conduct problems (e.g. lying, fighting) and attention-deficit/hyperactivity disorder (ADHD) are the leading causes of child mental health referral in the UK. These two disorders tend to occur in tandem (more than 40 per cent of children with a diagnosis of conduct disorder also have a diagnosis of ADHD) and can also be traced back to very similar prenatal experiences such as maternal distress or poor nutrition.
In this new study of participants from the Bristol-based 'Children of the 90s' cohort, 83 children with early-onset conduct problems were compared with 81 children who had low levels of conduct problems. The researchers assessed how the mothers' nutrition affected epigenetic changes (or DNA methylation) of IGF2, a gene involved in fetal development and the brain development of areas implicated in ADHD -- the cerebellum and hippocampus. Notably, DNA methylation of IGF2 had previously been found in children of mothers who were exposed to famine in the Netherlands during World War II.
The researchers from King's and Bristol found that poor prenatal nutrition, comprising high fat and sugar diets of processed food and confectionary, was associated with higher IGF2 methylation in children with early onset conduct problems and those with low conduct problems.
Higher IGF2 methylation was also associated with higher ADHD symptoms between the ages of 7 and 13, but only for children who showed an early onset of conduct problems.
Dr Edward Barker from King's College London said: 'Our finding that poor prenatal nutrition was associated with higher IGF2 methylation highlights the critical importance of a healthy diet during pregnancy.
'These results suggest that promoting a healthy prenatal diet may ultimately lower ADHD symptoms and conduct problems in children. This is encouraging given that nutritional and epigenetic risk factors can be altered.'
Dr Barker added: 'We now need to examine more specific types of nutrition. For example, the types of fats such as omega 3 fatty acids, from fish, walnuts and chicken are extremely important for neural development.
'We already know that nutritional supplements for children can lead to lower ADHD and conduct problems, so it will be important for future research to examine the role of epigenetic changes in this process.'
https://www.sciencedaily.com/releases/2016/08/160818085803.htm