Feeding children lots of fatty, sugary and processed foods may lower their IQ, while a diet rich in vitamins and nutrients appears to boost it, British researchers said.
This is particularly true during the first three years of life when the brain is developing rapidly, the study authors explained. They speculate that good nutrition may promote brain growth and cognitive development.
"We have found some evidence to suggest that a diet associated with increasing consumption of foods that are high in fat, sugar and processed foods in early childhood is associated with small reductions in IQ in later childhood," said lead researcher Kate Northstone, a research fellow in the department of social medicine at the University of Bristol.
A more health-conscious diet was associated with small increases in IQ, she said, adding that children should be encouraged to eat healthy foods from an early age.For the study, published online Monday in the Journal of Epidemiology and Community Health, Northstone's team collected data from the Avon Longitudinal Study of Parents and Children on 3,966 children born in 1991 and 1992.
The children's parents had answered questions about their kids' diets at age 3, 4, 7 and 8.5 years. The researchers identified three basic diets: "processed," crammed with fats, sugar and convenience foods; a "traditional" diet high in meats and vegetables; and a "health conscious" diet with lots of fruit, vegetables, salads, fish, rice and pasta.
The key seemed to be the diet at age 3, since diet at 4 and 7 seemed to have no effect on IQ, the research team noted. However, to truly understand the effect of diet on children's intelligence, further studies are needed, they said.