Better maternal diet boosts brain growth and IQ in kids

By Priyanjana Pramanik, MSc.Reviewed by Susha Cheriyedath, M.Sc.Nov 27 2024

Discover how a mother's high-quality diet during pregnancy can enhance her child's brain size and cognitive abilities, with lasting effects into adolescence.

Editorial: From mom’s diet to child’s big brain: in search of brain-optimal pregnancy diets. Image Credit: Saulich Elena / Shutterstock

In a recent editorial published in The American Journal of Clinical Nutrition, researchers assessed how maternal prenatal diet quality affects brain structure and the intelligence quotient (IQ) of children between 10 and 14 years of age. Their findings indicate that high-quality maternal diets during pregnancy significantly influence children’s brain structure along with cognitive outcomes that are mediated by structural brain changes.

Background

The human brain grows rapidly during gestation and childhood, requiring adequate nutrition to support its high energy demands. Proper nutrition during the first 1,000 days of life is crucial for laying the foundation for cognitive development. Nutritional deficiencies during pregnancy can harm neurodevelopment, alter gene expression, and cause lasting brain structural changes.

Research is shifting focus from individual nutrients to overall prenatal dietary patterns, recognizing the synergistic effects of different nutritional components. Better diet quality while pregnant has been linked to improved cognitive development in early and mid-childhood. Prenatal poor diets are associated with lower IQ, while healthy diets relate to better executive functioning and cognitive skills in children.

Structural brain changes may mediate the relationship between maternal diet and cognitive development in children. Animal studies suggest that high-fat diets and nutrient restrictions during pregnancy lead to structural brain changes and reduced cognitive abilities in offspring. In humans, there is emerging evidence linking prenatal diet to brain morphology and cognitive outcomes in adolescence, though the mechanisms remain unclear.

About the study

Researchers conducted a large prospective cohort study in the Netherlands, with participants comprising pregnant individuals with delivery dates between April 2002 and January 2006. The final sample sizes included dietary data from 6,485 mothers and 2,223 children with magnetic resonance imaging (MRI) data aged 10 and 1,582 at age 14, with 872 children having data at both points.

Diet quality assessments were based on a 293-item food frequency questionnaire that expectant mothers completed during their first trimester and which was used to score diet quality between 0 and 15 based on adherence to national dietary guidelines of the Netherlands, in which higher scores indicated healthier diets. Higher scores were correlated positively with the intake of beneficial nutrients like fiber and negatively with harmful components such as saturated fats.

During MRI scans, researchers measured global brain volumes (including white matter and gray matter) and cortical features such as gyrification (the process of developing folds), surface area, and thickness. Children also took four tests to measure IQ based on processing speed, memory, reasoning, and comprehension.

Regression analyses were adjusted for maternal characteristics such as energy intake, smoking, psychopathology, national origin, income, education, and age, as well as child characteristics such as breastfeeding duration, diet quality at age eight, and sex.

Findings

When recruited for the study, mothers were, on average, 31.2 years old. Between 64% and 66% had high education levels, while between 62% and 64% were Dutch nationals. The average diet quality score during pregnancy was 7.8 out of 15.

At age eight, children showed an average diet score of 4.5 and an average IQ of 103. Researchers found that better maternal diet quality during pregnancy was linked to larger brain volumes in children.

At age 10, subcortical volumes, gray matter, white matter, and total brain volumes showed significant associations, with cerebral gray matter and total volumes remaining correlated at age 14. These associations weakened when child diet quality was factored in but remained significant for age 10.

Prenatal diet quality was linked to larger cortical surface areas in specific brain regions (such as the occipital and frontal lobes) and differences in gyrification and cortical thickness, which varied by child age.

Better maternal diets also correlated with better cognitive outcomes in children, particularly matrix reasoning and vocabulary scores, with these improvements partially mediated by white matter and total brain volumes.

Conclusions

Overall, these findings indicate that better maternal diet quality during pregnancy supports larger brain volumes, better brain structure, and improved cognitive outcomes in children. These effects are stronger at younger ages (10 years) and diminish slightly with additional adjustments such as for head size or child diet quality.

This is the first study to show long-term associations between prenatal diet quality and brain morphology up to early adolescence, showing consistent associations between diet quality and brain volume in children of both ages.

Researchers also provided mechanistic insights into these relationships, suggesting that potential neurobiological pathways such as reduced inflammation or epigenetic changes could be the link. Nutrients like folate, zinc, iron, and protein may support critical neurodevelopmental processes.

This research highlights prenatal nutrition as a modifiable factor with long-term effects on brain and cognitive development. Future studies should validate findings across diverse populations and explore regional brain differences while also investigating whether prenatal diet quality impacts mental health or cognitive abilities later in adolescence or adulthood.