New Research: Maternal Diet During Pregnancy Linked to Child Brain Development and Intelligence

The new research, conducted by the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) at Herlev and Gentofte Hospital in collaboration with the University of Copenhagen, identified strong associations between maternal dietary patterns, and a child’s head growth and cognitive performance throughout childhood. Find the study here.

Maternal dietary patterns linked to cognitive development

The study examined two distinct dietary patterns during pregnancy: a ‘Western` dietary pattern high in sugar, fat, and processed foods, and a more ‘varied’ dietary pattern rich in diverse, nutrient-dense foods. Results showed that children born to mothers following the varied dietary pattern scored higher on IQ assessments at age 10 (WISC-IV FSIQ), while children exposed to the Western dietary pattern scored lower on early cognitive development tests at age 2½ (Bayley-III).

“We find that specific dietary patterns during pregnancy may influence the child’s cognition at different stages of development. Some dietary effects may be visible early on, while others only emerge later in childhood,” states Professor Morten Arendt Rasmussen, senior author on the study from the Department of Food Science, University of Copenhagen.

Linking dietary patterns to brain growth

The study also found that the varied dietary pattern was associated with increased head size and more rapid head growth from foetal life to age 10 - often used as an indirect marker of brain development. In contrast, the Western dietary pattern was linked to smaller head circumference and reduced growth.

Head size has long been associated with intelligence outcomes. This study strengthens that link, with measurements taken at 15 timepoints from pregnancy week 20 to the child’s 10th birthday - one of the most detailed datasets of its kind.

Researchers carefully accounted for many other influences on head size, including child height, weight, waist circumference, genetic predispositions, child diet and parental head circumference. This allowed them to disentangle the complex interaction between inherited traits and environmental exposures like nutrition.

A known but complex relationship: head growth and intelligence

Previous research has shown that children with larger heads perform better on intelligence tests. The new study confirms this association and adds more nuanced insight by using sophisticated growth models.

It shows that children with the greatest head growth from foetal life through age 10 also had the highest IQ scores at age 10, independent of genetic risk. Interestingly, no similar link was seen with the cognitive scores at 2½ years, suggesting that some aspects of brain development may only become evident later in childhood.

Breastfeeding and genetics also matter

The study also found that prolonged breastfeeding was independently associated with increased head growth, regardless of the mother’s diet during pregnancy. Furthermore, the effect of diet appeared strongest in children who had a high genetic predisposition for intelligence, pointing to a potential gene-environment interaction.

​As one of the lead researchers in the interdisciplinary COPSYCH project (COpenhagen Prospective Study on Neuro-PSYCHiatric Development), which has conducted comprehensive assessments of the neurocognitive and psychiatric profiles of children from the COPSAC2010 cohort, senior researcher and clinical psychologist in child and adolescent psychiatry, Jens Richardt Møllegaard Jepsen, says:​

“What is unique about the assessments we conduct when the children are 10 years old is that they are part of a thorough psychological evaluation of the child's development. This provides us with a stronger understanding of how factors such as diet and other early-life influences can significantly influence the child's future development”.

Blood markers reveal dietary patterns

Unlike traditional dietary studies that rely only on questionnaires, which can be prone to recall bias, this research also validated and incorporated maternal dietary measures through blood metabolomics: measuring small molecules in the mother’s blood that reflect dietary intake.

“By combining questionnaire data with blood metabolite profiles, we gained a much more objective picture of maternal diet and how it may shape the developing child,” says first author and medical doctor David Horner from COPSAC and the University of Copenhagen.

Strengths, limitations, and takeaways

Despite the comprehensive design, the study is observational in nature and cannot prove causality. While analyses were adjusted for many known factors, including genetics and socioeconomic background, unknown influences may still be at play.

Still, the results strongly suggest that early-life nutrition, during both pregnancy and breastfeeding, plays a central role in brain development and future cognitive performance.

“There is a complex interplay between genes, nutrition, and growth,” concludes David Horner. “Our study contributes an important piece to the puzzle, without claiming to know the full picture.”