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Unhealthy diet during pregnancy linked to ADHD symptoms in youth

Avoiding an unhealthy diet while pregnant may reduce the risk for ADHD symptoms in early-onset persistent youth, due to lower DNA methylation of the insulin-like growth factor 2 gene in the offspring, according to data published in the Journal of Child Psychology and Psychiatry.

“Children with an early-onset and persistent pattern of [conduct problems] represent a particular at-risk group, as they often show the highest rates of ADHD, as well as the greatest levels of psychosocial risk exposures in pregnancy (eg, poverty, maternal anxiety) and the early postnatal years (eg, harsh parenting, family discordance),” Jolien Rijlaarsdam, MS, of the Centre for Child and Family Studies, Leiden University, in the Netherlands, and colleagues wrote. “One prenatal risk that is a correlate of these psychosocial risks, yet has received far less attention, is diet. ‘Unhealthy diet’ (eg, high fat/sugar) is of particular interest as it has been reported to associate with both [conduct problems] and ADHD.”

The researchers evaluated to what degree a high-fat and high-sugar diet during pregnancy might be associated with ADHD symptoms in offspring, via the insulin-like growth factor 2 gene (IGF2) DNA methylation, for early-onset persistent (EOP) children compared with those with low levels of conduct problems. The IGF2 gene is involved in fetal and neural development. They drew data from 164 youths, including 83 EOP children and 81 with low levels of conduct problems, from the Avon Longitudinal Study of Parents and Children, in the United Kingdom.

They analyzed the interrelationships between high-fat and high-sugar diet, both prenatal and postnatal; IGF2 methylation, at birth and age 7 years, collected from blood; and ADHD symptoms, at ages 7 to 13 years. The researchers then compared the findings to determine if they differed between the two groups.

According to the researchers, prenatal unhealthy diet was positively associated with IGF2 methylation at birth for children in both the EOP and low conduct problems groups. Among participants in the EOP group, higher IGF2 methylation predicted ADHD symptoms, and prenatal unhealthy diet was associated with high ADHD symptoms indirectly, through higher IGF2 methylation.

“That we did not find continuity in IGF2 DNA methylation between birth and age 7 may support ideas focusing on the prenatal maternal health as an important risk for postnatal disease vulnerability,” Rijlaarsdam and colleagues wrote. “For example, a prenatal maternal high-fat and -sugar diet may alter the DNA methylation status of the IGF2 gene at birth, which in turn, may increase risk for a range of psychiatric and health disorders. The present study highlights pregnancy as being a promising window of opportunity for reducing the risk of ADHD symptoms associated with the nutritional environment and IGF2 DNA methylation. This is encouraging, given the potentially modifiable nature of nutritional and epigenetic risk factors.” – by Jason Laday

Disclosure: The researchers report no relevant financial disclosures.