A new study found that children who ate more ultra-processed foods early in life had smaller volumes in several brain regions by age 6.
Researchers did not find differences in the children's cognitive test performance despite the brain structure changes.
The findings highlight a potential link between early diet and brain development, but they do not prove that ultra-processed foods directly caused the observed differences.
What young children eat may influence more than just their physical growth — it could also be linked to how their brains develop.
A new study from researchers at Children's Hospital Los Angeles found that children who consumed more ultra-processed foods during infancy and early childhood had measurable differences in the size of several brain regions by age 6.
Ultra-processed foods are industrially manufactured products made with refined ingredients and additives designed to improve flavor, texture, or shelf life. Examples include some packaged baked goods, frozen meals, processed meats, and certain fast foods.
According to the researchers, these foods make up more than half of the calories consumed by many young children in the United States, making it important to better understand how they may affect early development.
“Our findings suggest that what children eat early in life may shape brain development in ways we’re just beginning to understand,” researcher Michael I. Goran, Ph.D., said in a news release.
“Even without differences in cognitive performance, we’re seeing measurable changes in brain structure.”
How the study was conducted
The study followed 144 Latino/Hispanic mother-child pairs from infancy through early childhood. Researchers collected detailed information about each child's diet at six months, 12 months, 24 months, and again at 72 months using repeated 24-hour dietary recalls.
When the children reached 6 years old, they underwent MRI scans so researchers could measure the size of several subcortical brain regions.
The children also completed age-appropriate cognitive assessments. Earlier evaluations measured language and motor skills, while later testing examined memory, attention, and processing speed. Throughout the study, researchers also tracked the children's height and weight.
What the findings mean
The researchers found that children with higher cumulative intake of ultra-processed foods had smaller volumes in several subcortical brain regions, including areas involved in reward, emotion, and motivation.
Specifically, every 10% increase in ultra-processed food intake was associated with nearly a 2% reduction in the volume of these brain structures.
Importantly, the study did not find differences in the children's cognitive performance. That means although researchers observed structural differences on brain scans, those changes were not reflected in the cognitive tests the children completed at age 6.
The authors say the findings suggest there may be a relationship between early dietary patterns and brain development, but more research is needed to determine exactly how these structural differences develop and whether they have any long-term effects.
Because this was an observational study, it cannot show that ultra-processed foods directly caused the brain differences. Future research will explore whether there are critical periods when diet has the greatest influence and what biological mechanisms may be involved.
“We still have much to learn about how early dietary exposures influence the developing brain,” Dr. Goran said. “Identifying the underlying mechanisms will be important for understanding what these findings mean for long-term health.”