英国研究人员多年随访1.4万名儿童后发现，3岁以前摄取垃圾食品较多者，日后智商可能低于同龄人。这一研究报告发表在7日出版的英国医学会下属《流行病和公共卫生杂志》月刊上。
这项研究涉及1991年和1992年出生的1.4万人。研究人员在研究对象3岁、4岁、7岁和8岁半时分别要求其父母回答调查问卷，了解其饮食种类细节。
研究主要关注3类饮食，一是富含加工脂肪和糖类的饮食；二是多肉类和蔬菜的“传统”饮食；三是“注重健康”的饮食，以沙拉、水果、蔬菜、面食和米饭为主。
当研究对象长至8岁半时，研究人员用韦氏智力量表测试其智商。结果显示，在4000名数据完整的研究对象中，3岁前食用加工食品较多者与饮食“注重健康”者智商存在明显差异。食用加工食品最多的五分之一儿童平均智商为101，饮食“注重健康”的五分之一儿童平均智商为106。
报告作者之一埃米特说：“这是一个非常小的差异，但这使得他们应对教育和人生中其他一些事务的能力较低。”
至于垃圾食品影响智商的原因，埃米特认为，以加工食品为主的饮食缺少对大脑发育至关重要的维生素和其他元素，“生命最初3年，大脑发育最快，这一阶段良好的营养可能促使大脑最佳发育”。（生物谷Bioon.com）
生物谷推荐原文出处：
J Epidemiol Community Health doi:10.1136/jech.2010.111955
Are dietary patterns in childhood associated with IQ at 8 years of age? A population-based cohort study
Kate Northstone1, Carol Joinson1, Pauline Emmett1, Andy Ness2, Tomá? Paus3,4,5
Abstract
Background Little is known about the effects of overall diet in childhood and intelligence later in life.
Methods The current study, based on the Avon Longitudinal Study of Parents and Children, uses data on children's diet reported by parents in food-frequency questionnaires at 3, 4, 7 and 8.5 years of age. Dietary patterns were identified using principal-components analysis and scores computed at each age. IQ was assessed using the Wechsler Intelligence Scale for Children at 8.5 years. Data on a number of confounders were collected, and complete data were available for 3966 children.
Results After adjustment, the ‘processed’ (high fat and sugar content) pattern of diet at 3 years of age was negatively associated with IQ assessed at 8.5 years of age—a 1 SD increase in dietary pattern score was associated with a 1.67 point decrease in IQ (95% CI ?2.34 to ?1.00; p<0.0001). The ‘health-conscious’ (salad, rice, pasta, fish, fruit) pattern at 8.5 years was positively associated with IQ: a 1 SD increase in pattern score led to a 1.20 point increase in IQ (95% CI 0.52 to 1.88; p=0.001).
Conclusion There is evidence that a poor diet associated with high fat, sugar and processed food content in early childhood may be associated with small reductions in IQ in later childhood, while a healthy diet, associated with high intakes of nutrient rich foods described at about the time of IQ assessment may be associated with small increases in IQ.
