Study Links Prenatal Dietary Pattern to Offspring Autism Risk

A small team of public health specialists from the University of Glasgow and the Norwegian Institute of Public Health reported a possible link between some cases of autism and prenatal diet.

In their study, published in JAMA Network Open, the group analyzed information in two large databases of medical information on thousands of mothers and daughters.

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by challenges in social communication and restricted, repetitive behaviours. It affects about 1% to 2% of the population and encompasses a range of symptoms and severity levels. Early signs often appear in early childhood, and diagnosis can be made through behavioural assessments. While the exact cause is unknown, both genetic and environmental factors are believed to play a role.

Prenatal diet may influence autism risk in offspring. Studies suggest that a healthy prenatal diet, characterized by high adherence to specific nutritional patterns, could be linked to a lower likelihood of autism diagnosis and autism-associated traits. Diets rich in certain nutrients, such as folic acid, vitamin D, and omega-3 fatty acids, have been associated with reduced autism risk. Conversely, deficiencies or imbalances in these nutrients may increase risk.

For the study, researchers analyzed patient information from two large databases: the Avon Longitudinal Study of Parents and Children and the Norwegian Mother, Father, and Child Cohort Study. The researchers looked at data for the years 2002 through 2008 and 1990 through 1992, which included data for children up to age 8. In all, they analyzed data for more than 95,000 mother/daughter pairs.

As part of their analysis, the researchers found a pattern—women who adhered to a "healthy diet" have a 22% lower chance of delivering a child with autism than women who ate a less-than-healthy diet.

In their study, they defined a healthy diet as one that included regular servings of vegetables, fruits, nuts, fish and whole grains, and excluded foods high in fat, processed meats, soft drinks and refined carbohydrates.

They also found that children born to mothers who regularly ate a healthy diet while pregnant were 24% less likely to develop social and/or communication problems irrespective of autism.

The researchers noted that the association in both cases was stronger in mother/daughter pairs than in mother/son pairs.

Reference: Friel C, Leyland AH, Anderson JJ, Havdahl A, Brantsæter AL, Dundas R. Healthy Prenatal Dietary Pattern and Offspring Autism. JAMA Netw Open. 2024;7(7):e2422815. doi:10.1001/jamanetworkopen.2024.22815