Nutritional Influences on the Brain in ADHD: Evidence from Neuroimaging Studies

Background/Objectives: Attention-deficit/hyperactivity disorder (ADHD) is increasingly recognized as a neurodevelopmental condition shaped by early-life biological and environmental factors. Emerging evidence highlights the role of nutrition in modulating key brain processes involved in ADHD, from gestational development through childhood. This review aims to examine how dietary interventions influence neuroimaging outcomes in individuals with ADHD, assessing whether nutritional approaches can modulate brain structure, function, or connectivity. Methods: A systematic search of PubMed, Scopus, and Web of Science was conducted to identify studies examining the effects of dietary interventions on neuroimaging outcomes in individuals with ADHD. Study quality was assessed using Cochrane RoB 2.0, ROBINS-I, the Newcastle–Ottawa Scale, and the JBI Critical Appraisal Checklist, according to study design. Results: A total of 1059 records were identified, and 4 studies met the final inclusion criteria. The included studies suggest that prenatal vitamin D exposure, omega-3 fatty acids, and micronutrients such as zinc may be associated with structural, functional, and neurometabolic brain characteristics relevant to ADHD. Reported findings included associations with brain volume, glutamatergic regulation, white matter organization, resting-state network integrity, and inattentive symptom. Conclusions: Current evidence supports the hypothesis that nutrition may influence neurodevelopmental processes involved in ADHD, including brain maturation and neural network organization. Although findings remain heterogeneous and limited in number, nutrition appears to represent a biologically plausible and potentially modifiable factor within the developmental framework of ADHD. Further longitudinal and multimodal neuroimaging studies are needed to clarify the mechanisms linking nutrition, brain development, and ADHD.