Scientists led by a team from the University of Copenhagen in Denmark have found a "strong link" between Western-style diets and neurodevelopmental conditions, including autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).
While the research doesn't prove direct cause and effect, it suggests some kind of association—adding to what we already know about the diets of pregnant women and how they can affect the health and development of their children.
The study team looked at data from 61,237 mothers and their children, cross-referencing diet habits of the moms while pregnant with the neurodevelopment of their kids. Even small shifts toward Western dietary patterns were linked to significant increases in the likelihood of ADHD in the next generation. One of the cohorts also showed a link between consuming a Western diet during pregnancy and the likelihood of a child developing autism.
"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," says food scientist David Horner, from the University of Copenhagen.
While the results are worrying, there's also something positive to take from them: that even small changes toward a healthier diet while pregnant can have a positive effect on child brain health.
Four cohorts were used in the study. In the primary one, involving 508 mothers and children, kids were clinically assessed for neurodevelopmental disorders at 10 years of age. In the other cohorts, diagnosis data was collected through self-reporting and national registries – though all the cohorts showed the same associations.
The researchers took steps to account for other factors that may have influenced the results, including genetic risk and the diets of the children themselves. This adds to the credibility of the main association.
"When comparing across cohorts, we observed the strongest associations in the first and second trimesters, suggesting that brain development during this period is particularly sensitive to maternal nutritional influences," says food scientist Morten Arendt Rasmussen, from the University of Copenhagen.
The team was also able to identify numerous blood metabolites (or chemical flags) that were linked to the diets of the mothers. They give us some idea of the pressures that could be influencing brain development – inflammation and cell damage, for example.
While we're getting better at understanding and managing both ASD and ADHD, these conditions do come with challenges related to learning and development. These challenges can sometimes persist into adulthood too.
There's already plenty of existing evidence about how baby health can be affected in the womb, but the researchers want to see more done to promote balanced diets in pregnant moms – specifically, better guidelines.
"Our analysis not only confirms a strong link between diet and ADHD risk but also identifies specific nutrients and foods that could serve as the foundation for improved dietary guidelines and preventative strategies," says Horner.
"This opens new possibilities for refining dietary recommendations and promoting healthier outcomes for future generations."
The research has been published in Nature Metabolism.