Eating Processed Foods Could Make Kids Dumber

Parents hoping for smart kids might want to focus first on what’s going into their youngsters’ bellies, not their heads.

A diet, high in fats, sugars and processed foods in early childhood may lower IQ, while a diet packed full of vitamins and nutrients may do the opposite, suggests research published by academics in the University of Bristol's School of Social and Community Medicine.

The study, published in the Journal of Epidemiology and Community Health, bases its findings on participants in the Avon Longitudinal Study of Parents and Children (ALSPAC), which tracks the long term health and well-being of roughly 14,000 children born in 1991 and 1992.

Parents completed questionnaires, detailing the types and frequency of the foods and drinks their children consumed when they were three, four, seven, and eight and a half years old.

This information was then quantified to produce a dietary pattern score for three different types of diet:  “processed,” high in fats and sugars; “traditional,” high in meat and two vegatables; and “health conscious,” high in salad, fruit and veggies, rice and pasta.

IQ was measured using the Wechsler Intelligence Scale for Children when the kids were eight and a-half-years old.

Dietery factor

The results show after taking account of potentially influential factors, a diet consisting predominantly of processed foods at three years old was associated with a lower IQ at the age of eight and a half, regardless of whether the diet improved after that age.

Every one-point increase in dietary pattern score was associated with a 1.67 fall in IQ.

On the other hand, a healthy diet was associated with a higher IQ at the age of eight and a-half, with every one-point increase in dietary pattern linked to a 1.2 increase in IQ.

Dietary patterns between the ages of four and seven had no impact on IQ.

The authors say these findings, although modest, are in line with previous ALSPAC research showing an association between early childhood diet and later behavior and school performance.

Early development

"Our research suggests that any cognitive/behavioral effects relating to eating habits in early childhood may well persist into later childhood, despite any subsequent changes (including improvements) to dietary intake,” said Dr. Kate Northstone, Research Fellow in the School of Social and Community Medicine.

The authors say the brain grows the fastest during the first three years of life, which could explain the study findings. They also point to previous research indicating head growth during the first three years in linked to intellectual ability as well.

Dr. Pauline Emmett, Senior Research Fellow in the School of Social and Community Medicine, added, "It is possible that good nutrition during the first three years of life may encourage optimal brain growth, advocating further research to determine the extent of the effect early diet has on intelligence."