Children who eat a nutritious diet of fruits and vegetables have higher IQ levels, while a diet of processed and sugary foods has the opposite effect. And it seems the earlier you start your child on a healthy diet, the better.
The Avon Longitudinal Study of Parents and Children, which has tracked around 14,000 children for five years, discovered a direct correlation between eating habits and IQ scores. For every point gained from eating healthily, there was a 1.2-point increase in the IQ level. Conversely, every point lost by eating processed food resulted in a 1.67 fall in the IQ score.
The researchers believe the greatest benefits are seen when a child starts early on a healthy diet, and especially during the first three years.
(Source: Journal of Epidemiology & Community Health, 2011; doi: 10.1136/jech.2010.111955).