Cognitive/Behavioral effects of childhood eating habits may persist long-term

Children who eat a diet high in fat, sugar, and processed foods at age 3 may have a slightly lower intelligence quotient (IQ) later in childhood, a study published online in the Journal of Epidemiology and Community Health suggests.

In contrast, children who eat a healthy diet around the time of IQ assessment may have slightly higher scores.

Researchers from the University of Bristol, United Kingdom, analyzed data on 3,966 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). Parents reported their children’s diet at 3, 4, 7, and 8.5 years using a food-frequency questionnaire. IQ was determined at a mean age of 8.5 years using a short form of the Wechsler Intelligence Scale for Children.

After adjusting for breastfeeding duration, maternal education, and other factors, a negative association was found between a “processed” pattern diet high in fat and sugar at age 3 years with IQ at age 8.5 years. For each 1-standard deviation (SD) increase in processed pattern score, there was a 1.67-point decrease in IQ. A 1-SD increase in a “health-conscious” pattern diet rich in salad, fruits, vegetables, fish, rice, and pasta, however, was associated with a 1.20-point higher IQ. Dietary patterns between ages 4 years and 7 years were not predictive of IQ at age 8.5 years.

A possible explanation for these findings, according to the researchers, is that the brain grows fastest during the first 3 years of life, and it is possible that good nutrition during this period encourages optimal brain growth. The findings are consistent with previous studies of the ALSPAC cohort and suggest that any cognitive/behavioral effects relating to eating habits in childhood may persist into later childhood, despite any subsequent changes (including improvements) to dietary intake.

Northstone K, Joinson C, Emmett P, Ness A, Paus T. Are dietary patterns in childhood associated with IQ at 8 years of age? A population-based cohort study. J Epidemiol Community Health. 2011. Epub ahead of print.