Dr. Lisa Smithers of the University of Adelaide and colleagues studied 7,000 children compared a range of dietary patterns, including traditional and contemporary home-prepared food, ready-prepared baby foods, breastfeeding and 'discretionary' or junk foods on children from birth to 24 months.
"Diet supplies the nutrients needed for the development of brain tissues in the first two years of life, and the aim of this study was to look at what impact diet would have on children's IQs," Smithers said in a statement. "We found that children who were breastfed at six months and had a healthy diet regularly including foods such as legumes, cheese, fruit and vegetables at 15 and 24 months, had an IQ up to 2 points higher by age eight.
Those children who had a diet regularly involving biscuits, chocolate, soft drinks and chips in the first two years of life had IQs up to 2 points lower by age 8."
Smithers said the differences in IQ were not huge, but the study provides some of the strongest evidence to date that dietary patterns from six to 24 months have a small but significant effect on IQ.