A new British study on child nutrition has found a weak but still troubling association for any parents who have leaned on fast food too much to feed their kids: Bad nutrition in pre-school years can mean lower IQs for children once they are in grade school.
Researchers compared the parent-reported dietary habits of children at ages 3, 4, 7 and 8 with their performance on an IQ test at age 8. The results:
-- IQ scores averaged 1.67 points lower for children who at age 3 consumed "processed" diets high in fat and sugar.
-- IQ scores averaged 1.20 points higher for children who at age 8 consumed health-conscious diets (lots of salad, rice, pasta, fish, fruit).
The study is based on the monitoring of 14,000 born in southwest England in the early 1990s. Roughly half took the IQ test, and provided the basis for this nutritional study.
The statistical relationships between early diet and IQ scores got weaker when the researchers adjusted the results for other potential influences -- such as economic status and the education levels of the mothers.
Diets at ages 4 and 7 also showed no statistical bearing one way or the other on IQ scores at age 8.
The researchers noted that a poor diet at age 3 appeared to have a durable impact on IQ at age 8 -- even for children whose diets improved over time.
"This suggests that any cognitive/behavioural effects relating to eating habits early in childhood may well persist into later childhood, despite any subsequent changes (including improvements) to dietary intake."