Strong Link Between a Western Diet During Pregnancy and ADHD

New research from Denmark shows that a mother’s diet during pregnancy – characterized by a Western dietary pattern high in fat and sugar and low in fresh ingredients – can increase the risk of neurodevelopmental disorders such as ADHD and autism in children. Researchers see potential for targeted dietary interventions during pregnancy to reduce this risk.

How the Mother’s Diet Increases the Child’s Risk of ADHD

It has long been known that smoking, alcohol and unhealthy diets affect fetal development. Now, a large clinical study conducted by the University of Copenhagen and the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) at the Danish Paediatric Asthma Center, Herlev and Gentofte Hospital, has found a link between a mother’s diet during pregnancy and the development of ADHD and autism in children. “The more a woman adheres to a Western diet during pregnancy – high in fat, sugar and refined products, and low in fish, vegetables and fruit – the greater the risk appears to be for her child to develop ADHD or autism,” says lead author Dr. David Horner, MD, PhD.

The study identified a Western dietary pattern using data-driven analysis. Even moderate shifts along this dietary spectrum were associated with significantly increased risk. For example, slight deviations towards a more Western diet were associated with a 66% increased risk of ADHD and a 122% increased risk of autism. However, this also offers an opportunity: even small adjustments of the diet away from a Western pattern could potentially reduce the risk of neurodevelopmental disorders.

Over 60,000 Mother-Child Pairs Analyzed

To arrive at these findings, the researchers analyzed dietary patterns, blood samples, and ADHD diagnoses in four large independent cohorts in Denmark and the United States, which included more than 60,000 mother-child pairs. The blood samples were analyzed using metabolomics, which provides insights into the biological mechanisms between diet and neurodevelopmental disorders and serves as a validation method for the results. The link between Western dietary patterns and ADHD was observed in all four cohorts and validated in three of them using three different methods, which David Horner says adds to the credibility of the study.

The study is based on an extremely detailed and robust data set involving almost 600 children who were clinically evaluated for neurodevelopmental disorders at the age of 10. To ensure the reliability of the results, the researchers took into account a number of factors, including genetics, which is known to play an important role in neurodevelopmental disorders. Nevertheless, a clear link between a mother’s western diet and the risk of ADHD and autism remained.

Greatest Risk in Early Pregnancy

One of the greatest strengths of this study is the high quality of the biological samples, which included repeated metabolic measurements during pregnancy and childhood. This enabled the researchers to demonstrate that the link between nutrition and ADHD risk was strongest in early and mid-pregnancy. “When comparing the cohorts, we observed the strongest associations in the first and second trimesters, suggesting that brain development is particularly sensitive to maternal nutritional influences during this period,” explains lead author Professor Morten Arendt Rasmussen of the University of Copenhagen.

The researchers identified 43 specific metabolites in maternal blood that were associated with a Western diet and could help explain the link between diet and neurodevelopmental disorders. They found that 15 of these 43 metabolites were particularly associated with increased ADHD risk. Many of these metabolites originate from dietary intake and play key roles in the regulation of inflammation and oxidative stress – factors considered crucial for early neurodevelopment.

Are Current Dietary Guidelines for Pregnant Women Effective?

According to David Horner, this study raises important questions about whether current dietary guidelines for pregnant women are sufficient. In Denmark, dietary advice for pregnant women largely mirrors that for the general population, emphasizing a balanced diet rich in vegetables, fruits, whole grains, and fish rather than red meat.

“We know that nutrient requirements increase during pregnancy, and our study highlights the importance of diet composition for fetal development. Although the Nordic diet is often considered healthy, our data show that many pregnant women follow dietary patterns that could be optimized to better support their child’s development. This study raises the question of whether existing dietary recommendations during pregnancy are being followed sufficiently – and whether they are having the desired effect on the health of the child,” says David Horner. He adds that the study not only shows a link between diet and ADHD risk, but also provides insights into specific nutrients and food groups that could play a crucial role in fetal brain development.

According to the researcher, the analysis not only confirms a strong link between diet and ADHD risk, but also identifies specific nutrients and foods that could serve as a basis for improved dietary guidelines and prevention strategies. Understanding how a mother’s diet affects fetal development will help identify the key nutrients and dietary changes needed to reduce the risk of neurodevelopmental disorders. This opens up new possibilities for refining dietary recommendations and promoting healthier outcomes for future generations.

The study was conducted by COPSAC and the University of Copenhagen in collaboration with the Danish National Birth Cohort (DNBC) and the VDAART cohort in the United States. The study finds a strong association between a Western diet pattern during pregnancy and increased risk of neurodevelopmental disorders, including ADHD and autism. The results for ADHD were validated in three independent mother-child cohorts. The strongest associations between a Western diet and ADHD risk were observed in the first and second trimesters, suggesting that fetal brain development is particularly sensitive to maternal diet during these periods. The researchers used a combination of dietary records, blood analysis, genetic data and clinical diagnoses from four large mother-child cohorts to examine whether a Western diet during pregnancy is associated with an increased risk of ADHD and autism in children. However, there were also limitations. This is an observational study, meaning it shows a strong statistical association but does not conclusively prove that a Western diet causes ADHD or autism.