New Research: Strong Link Between Western Diet During Pregnancy and ADHD and Autism

New research conducted by an international research team, including the University of Iceland, reveals that a mother’s diet during pregnancy—characterised by a Western dietary pattern high in fat and sugar and low in fresh ingredients—may increase the risk of neurodevelopmental disorders such as ADHD and autism in children. The research findings were published in the prestigious journal Nature Metabolism. Researchers see potential for targeted dietary interventions during pregnancy to reduce this risk.

To reach these findings, researchers analysed dietary patterns, blood samples, and ADHD diagnoses across four large independent cohorts in Denmark and the United States, encompassing more than 60,000 mother-child pairs. Blood samples were analysed using metabolomics, providing insights into the biological mechanisms linking diet to neurodevelopmental disorders and serving as a validation method for the results. To ensure the reliability of the findings, researchers accounted for a range of factors, including genetics, which have been known to play a major role in neurodevelopmental disorders.  

Nevertheless, a clear association between a maternal Western diet and the risk of ADHD and autism remained. The greater a woman's adherence to a Western diet in pregnancy - high in fat, sugar, and refined products while low in fish, vegetables, and fruit—the greater the risk appears to be for her child developing ADHD or autism. 

The research scientists point out that even modest changes towards a more Western diet were associated with a 66% increased risk of ADHD and a 122% increased risk of autism. However, this also presents an opportunity: even minor dietary adjustments away from a Western pattern could potentially reduce the risk of neurodevelopmental disorders. This is an observational study, meaning it shows a strong statistical association, but does not conclusively prove a causative link between Western diet causes ADHD or autism.

Results can be used to improve dietary guidelines

The strongest associations between a Western diet and ADHD risk were observed in the first and second trimesters, suggesting that foetal brain development during this period is particularly sensitive to maternal nutrition.  

The research team further points out that the results raise questions about whether nutritional recommendations for pregnant women need to be revised or improved in some way.  Generally, pregnant women are advised to eat the same food as other people, emphasising the consumption of vegetables, whole grains, and fish.  However, the study raises questions about whether these recommendations are sufficiently followed during pregnancy.  At the same time, the study provides information on what types of food and food groups can play an important role in brain development in the foetus, information that could potentially be added to nutritional recommendations for pregnant women. 

Scientists at the University of Copenhagen led the research, and among the participants was Þórhallur Ingi Halldórsson, professor at the Faculty of Food Science and Nutrition. He is one of the scientists in charge of collecting the data the study is based on, and he says that the idea of exploring dietary patterns during pregnancy was partly sparked during his previous collaboration with international colleagues years ago. One strength of the study, he says is that “by using many databases, it was possible to establish that the association with the Western diet was not a chance finding as the association was consistent across different study populations. This consistency, along with the metabolomics measurements utilities, strengthens the conclusions presented in the article”, Þórhallur concludes. 

The scientific article: „ A Western dietary pattern during pregnancy is associated with neurodevelopmental disorders in childhood and adolescence,“ can be accessed on the Nature Metabolism website.