What you eat in your first years of life could affect how smart you are as a teenager. A new analysis of 73 studies, published in Advances in Nutrition, shows that poor nutrition during infancy is linked to lower intelligence scores in adolescence—even after accounting for other factors like income and education.
The Research
Researchers from Swansea University, led by Professor Hayley Young, aggregated data from 48 controlled trials and 25 prospective longitudinal studies tracking youth aged 8 to 19. Supported by the IAFNS Cognitive Health Committee, the team examined a wide range of nutrients: iron, iodine, choline, vitamin D, polyphenols, fatty acids, grains, and multi-nutrient combinations. They found that unhealthy dietary patterns in infancy consistently predicted lower cognitive performance later on, even when controlling for confounding variables. However, evidence for dietary interventions during adolescence itself was mixed, leaving open the question of whether the teenage years represent a second window of neuroplasticity that nutrition can influence.
Why It Matters
This doesn't mean you should panic if your diet wasn't perfect as a child. But it does underscore that early nutrition shapes the brain's foundation during critical developmental windows. The brain undergoes massive remodeling during infancy and again in adolescence due to hormonal changes. While we can't change the past, understanding this timeline can help parents, educators, and policymakers prioritize early nutrition. For adolescents, the findings suggest that while diet still matters, the effects may be smaller or harder to detect—more research is needed.
What You Can Do
For parents: focus on a balanced diet rich in iron, iodine, choline, and omega-3s from the start. For teens: eating well won't hurt, and it may help, especially if combined with cognitive training. Everyone can benefit from understanding their own baseline: take our free IQ test to see where you stand, and consider brain training to sharpen skills.
Source: Neuroscience News
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