Food choices made in early childhood could leave a lasting imprint on cognitive development. A large study conducted in Brazil shows that regular consumption of ultra-processed foods at the age of two is associated with lower intellectual performance several years later.
When food shapes the brain
What toddlers eat not only fuels their immediate growth: it could also influence their future intellectual abilities. This is suggested by a new analysis from the Pelotas birth cohort, one of the most comprehensive population studies in Latin America.
Researchers followed several thousand children from birth and looked at their eating habits at the age of two. Result: children whose diet was dominated by so-called “unhealthy” products – instant noodles, sugary biscuits, candies, sodas or cold meats – obtained, at six or seven years of age, IQ scores significantly lower than the others.
This association persisted even after taking into account numerous social and family factors, such as the mother’s education level, socioeconomic status and stimulation at home.
Ultra-processed products: a discreet but durable brake
Contrary to popular belief, the study does not show that a “healthy” diet makes children smarter than average. Fruits, vegetables and legumes were already consumed by the vast majority of children in the cohort: almost 92% of them followed this type of diet. In this context, these foods constitute a reference level rather than a factor of cognitive overperformance.
The difference appears especially with the regular addition of ultra-processed foods. According to researchers, these products could disrupt brain development through several biological mechanisms: chronic inflammation, oxidative stress and disruption of the gut-brain axis, a key communication system between the digestive tract and the brain.
“Cumulative disadvantage” among the most vulnerable children
The negative effects of poor nutrition were even more marked in children already presenting early biological vulnerabilities: low weight or small size at birth, reduced head circumference during the first year of life. For them, the combination of a fragile start and unbalanced nutrition creates what researchers call a “cumulative disadvantage.”
In other words, even before entering school, some children have already lost part of their cognitive potential. If the brain remains plastic, this period around two years seems particularly critical, which makes late interventions more difficult.
A global public health issue
Even though the study was carried out in southern Brazil, in Pelotas, its conclusions go far beyond this framework. Ultra-processed foods are now omnipresent in the diets of young children, including in high-income countries.
For researchers, the message is clear: strengthening nutritional advice during pediatric visits and limiting early exposure to ultra-processed products could have long-term benefits, well beyond physical health. Because long before school report cards, cognitive inequalities sometimes begin… in the little ones’ plates.