Dr. Smithers and her team examined the link between the eating habits of children at 6 months, 15 months and 24 months and their IQ at 8 years. They found for children breastfed at 6 months and at 15 and 24 months consuming a healthy diet of homemade foods and fruits and vegetables, there was a 2 point increase in IQ at age 8 years.
During the first 2 years of life, diet supplies the nutrients necessary for the development of neural tissues. Previous studies have examined prolonged breastfeeding as a cause of higher IQ scores and the influence of iron-enriched formula on cognition and behavior. A small-scale 2009 study found a link between a diet of breastfeeding and fresh fruits and vegetables and home-made foods at 1 year of age and a ~2.7 point increase in IQ at age 4.
Smithers’ study — which had a larger study group and covered more ages than previous studies — observed 7,097 children, breaking their dietary patterns into four areas. The first pattern, Homemade Traditional, consisted of home-cooked meals and desserts. The second pattern, Discretionary, consisted of junk foods (cookies, chips, etc.). The third pattern, Ready-prepared Baby Foods, consisted of pre-made, packaged baby food. The fourth pattern, Breastfeeding and Home-prepared Contemporary, was studied at only 6 and 15 months of age; Home-prepared Contemporary referring to raw fruits and vegetables, cheese, nuts and legumes. At 8 years of age, the team measured the children’s IQ using the Wechsler Intelligence Scale for Children.
The study found the following associations between dietary pattern and IQ:
1. Across the board, there was a positive association between Breastfeeding and Contemporary patterns and IQ, and a negative association between Discretionary pattern and IQ. Children who breastfed at six months and followed the Homemade Traditional and Home-prepared Contemporary patterns at 15 and 24 months, had a 2 point higher IQ at age 8. Children who followed the Discretionary pattern had a 2 point lower IQ at age 8.
2. The Home-made Traditional pattern had a positive association to higher IQ scores at 6 months, but at 15 months there was no association and at 24 months there was a negative association.
3. Children receiving Ready-prepared Baby Foods at 6 and 15 months showed a negative association to IQ; however, at 24 months there was a positive association.
4. Ready-prepared Baby Food pattern at 6 and 15 months had a negative association to IQ, compared to Ready-prepared Baby Foods (foods requiring little preparation, i.e. bread, yogurt, cereal) at 24 months, which had a positive association.
The study’s findings show that a child’s cognitive development is definitely affected by diet. While a 2-point increase in IQ is not large, it does point to definite evidence that dietary patterns before the age of 2 years, does affect IQ by age 8. So, get out your food processors parents and hide the chips.