Data tying Western diet during pregnancy to autism, ADHD support need for proper nutrition
Key takeaways:
- A Western diet pattern is associated with increased risk for autism and ADHD.
- A study author noted that health care practitioners should continue “emphasizing well-rounded maternal nutrition.”
A Western dietary pattern during pregnancy was associated with significantly higher risks for multiple neurodevelopmental disorders, a study in Nature Metabolism revealed.
Specifically, the diet appeared to raise the risk for autism and ADHD by 122% and 66%, respectively, according to a press release.
But such findings “do not prove that diet alone causes ADHD or autism,” David Horner, MD, PhD, from University of Copenhagen in Denmark, told Healio. “Multiple factors — genetics, environment, maternal health — interact in complex ways.”
Horner explained that the analysis is notable for several reasons, such as its emphasis on a “data-driven Western diet — ie, high in processed foods, saturated fats and sugars, and low intakes of fish, fruit and vegetables.”
“Many researchers have long suspected that maternal diet could shape early neurodevelopment, but this study stands out for its focus on multiple cohorts (including both dietary questionnaires and metabolomic data), which adds depth to the findings,” he added.
He further highlighted the use of blood metabolomics “to help confirm dietary patterns, which is a novel step in validating self-reported food frequency questionnaires.”
Strong associations
Horner and colleagues analyzed data from the Copenhagen Prospective Studies on Asthma in Childhood 2010 cohort, which included mothers who self-reported their dietary patterns at 24 weeks of pregnancy and their children (n = 508) who were clinically assessed for neurodevelopmental disorders at age 10 years.
The researchers then validated their findings by assessing dietary patterns, blood samples and ADHD diagnoses of more than 60,000 pairs of mothers and children from three independent cohorts in Denmark and the U.S.
Horner and colleagues reported that there were strong associations between the Western dietary pattern and the risk for ADHD diagnosis and autism diagnosis.
The strengths of such links were greatest during the first and second trimesters of pregnancy, “suggesting that this may be a particularly sensitive period of neurodevelopment to dietary influences,” they wrote.
Horner told Healio that the associations were also stronger “in mothers with higher BMI or genetic predisposition, hinting at a multifactorial interaction.”
Such a finding “highlights how broader lifestyle factors (like BMI and exercise) may interact with diet,” he said. “Encouraging all-around healthy living remains a key prenatal goal.”
The researchers additionally identified 43 specific metabolites in maternal blood linked to a Western diet, of which 15 were tied to a higher risk for ADHD, Horner noted in the release.
“Many of these metabolites are derived from dietary intake and play key roles in regulating inflammation and oxidative stress — factors believed to be critical in early neurodevelopment,” he said in the release.
Data reinforce current guidelines
Anna Maria Siega-Riz, MS, PhD, dean of the School of Public Health and Health Sciences and professor in the departments of nutrition, biostatistics and epidemiology at University of Massachusetts Amherst, told Healio that the data add “evidence to the importance of maternal diet during pregnancy and early on in the life of the child.”
“It reinforces, in fact, what we've been recommending, which is diets that are predominantly plant-based, moderate fat intake [and] have protein from different sources,” Siega-Riz, who is not affiliated with the study, said.
During fetal development, the brain rapidly grows around 28 weeks, Siega-Riz said. So, additional studies are needed to better understand the impact of maternal diet during early vs. late pregnancy.
“When we think about brain growth for the child, it starts in utero and keeps going through the first 2 years of life, which is really critically important, and then starts to plateau around 4 or 4 and a half years,” she said. “This provides the rational for studying the perinatal and early childhood periods when the outcomes are related to neurocognition.”
Frame diet talks around risk reduction
According to Horner, clinicians could consider framing discussions on maternal diets around reducing risk.
“For mothers with higher BMI or metabolic issues, and with a significant family history, tailored nutritional guidance may be especially important,” he told Healio.
He pointed out that providers should further offer reassurance and emphasize “that no one study should provoke anxiety or sudden changes to official guidelines."
“Instead, this research underscores why providers should continue emphasizing well-rounded maternal nutrition,” he added.
Future research on the Western diet during pregnancy and its health effects may involve intervention trials but “randomizing pregnant women to specific diets raises ethical and practical challenges,” Horner noted.
“Research using animal models or targeted biochemical pathways could clarify how maternal diet impacts fetal brain development and whether certain nutrients or nutrient imbalances are key,” he said. “Incorporating metabolomic and genetic data more routinely can [also] help overcome the known limitations of self-reported diet and better isolate causal pathways.”
For more information:
David Horner, MD, PhD, can be reached at david.horner@dbac.dk.
Anna Maria Siega-Riz, MS, PhD, can be reached at asiegariz@umass.edu.
References:
- Horner D, et al. Nat Metab. 2025;doi:10.1038/s42255-025-01230-z.
- New research: Strong link between Western diet during pregnancy and ADHD. Available at: https://food.ku.dk/english/news/2025/new-research-strong-link-between-western-diet-during-pregnancy-and-adhd/. Published March 4, 2025. Accessed March 10, 2025.
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