Prenatal diet is emerging as a potential contributing factor to autism. Until now, however, studies investigating the link between prenatal dietary patterns and autism diagnosis or autism-associated traits have relied on small sample sizes and may have been affected by recall bias.
For the current study, researchers conducted analyzed data from 84, 548 mother-infant pairs from the Norwegian Mother, Father, and Child Cohort Study (MoBa) and 11,670 pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC).
The researchers assessed maternal consumption of healthy dietary patterns while pregnant with self-reported food frequency questionnaires. Dietary patterns were divided into three groups: low, medium, and high adherence to a healthy prenatal diet. A healthy diet was defined by worldwide guidelines, which encourage the consumption of vegetables, fish, nuts, and whole grain foods and discourage the consumption of red and processed meats, soft drinks, foods high in fats, and/ or refined carbohydrates.
Ultimately, the researchers found that high adherence to a healthy prenatal diet was linked to a 22% lower incidence of autism diagnosis. A healthy prenatal diet was also linked to a reduced likelihood of social communication difficulties at ages 3 and 8. The researchers, however, did not find consistent associations between prenatal diet and restrictive and repetitive behaviors, which are also core traits of autism.
Limitations to the study include that dietary data was self-reported and that single diet assessments may not represent dietary changes throughout pregnancy. The findings nevertheless suggest that promoting a healthy diet during pregnancy via public health campaigns and prenatal care programs could potentially reduce autism risk among children and improve neurodevelopmental outcomes.
Sources: Neuroscience News, JAMA Network Open