Study Summary: Diet Soda, Aspartame, and Autism Risk in Boys

 

Study Summary: Diet Soda, Aspartame, and Autism Risk in Boys

A 2023 study titled “Daily Early-Life Exposures to Diet Soda and Aspartame Are Associated with Autism in Males: A Case-Control Study” was published in the peer-reviewed journal Nutrients.

The research used data from the Autism Tooth Fairy Study in the United States and included:

• 235 children diagnosed with autism spectrum disorder (ASD)
• 121 neurotypically developing children as controls

To estimate early-life exposure, mothers were asked to recall their consumption of diet soda and aspartame during pregnancy and breastfeeding.

What the study found

The study reported that boys whose mothers consumed at least one diet soda per day, or an equivalent amount of aspartame, during pregnancy or breastfeeding had more than three times higher odds of being diagnosed with autism, especially non-regressive (early-onset) autism.

The study did not find a significant association in girls.

Important limitations

The authors made it clear that this study does not prove causation. It has important limitations, including:

• It relied on retrospective dietary recall, which can be inaccurate
• It was an observational case-control study, not a randomized trial
• It can show an association, but not confirm that aspartame or diet soda directly caused autism

Why the study matters

Even with its limitations, the study raises questions about whether frequent diet soda and aspartame exposure during pregnancy may deserve closer investigation. The authors called for more prospective research to better understand whether there is a real connection.

Important Note

This study should not be used to make definitive claims that diet soda or aspartame causes autism. Anyone with concerns about pregnancy nutrition should speak with a qualified healthcare professional and rely on the broader body of scientific evidence, not a single study alone.