Beyond Iron: Supporting Brain Function Through Diet

While iron has received considerable attention as a critical determinant of adolescent brain health, optimal neurodevelopment is fundamentally dependent on the orchestrated availability of a broad spectrum of micronutrients acting in concert. Zinc, a modulator of vesicular glutamatergic neurotransmission and NMDA receptor function, is essential for synaptic plasticity, long-term potentiation, and the maintenance of cognitive flexibility; both deficiency and excess impair plasticity and have been linked to memory deficits and mood dysregulation. Iodine underpins thyroid hormone synthesis, which in turn drives neuronal proliferation, migration, differentiation, and myelination during critical developmental windows, with even mild deficiency producing measurable reductions in executive function and academic performance. 

Vitamin D, acting through nuclear vitamin D receptor (VDR)-mediated transcription in neurons and glial cells, modulates brain-derived neurotrophic factor (BDNF) signalling, glutamatergic and GABAergic balance, and neuroinflammatory pathways, with low status consistently associated with cognitive decline and internalising symptoms. 

Vitamin A, via retinoic acid receptor signalling, regulates neuronal differentiation and synaptic remodelling, influencing learning and memory processes at the molecular level. B vitamins, particularly folate, B6, and B12, are indispensable for one-carbon metabolism, homocysteine regulation, epigenetic methylation, and the synthesis of monoamine neurotransmitters including serotonin, dopamine, and noradrenaline; insufficiency drives hyperhomocysteinaemia, neuronal atrophy, and progressive cognitive impairment.³

Alongside these micronutrients, long-chain omega-3 polyunsaturated fatty acids,  particularly docosahexaenoic acid (DHA) are structural constituents of neuronal phospholipid membranes, where they regulate membrane fluidity, receptor conformation, and synaptic signal transduction. 

Adequate omega-3 status has been associated with improvements in learning, memory consolidation, attentional function, and emotional regulation, with the adolescent brain's continued myelination and synaptic remodelling rendering it especially responsive to the availability of these fatty acids. ^5,6

Critically, these micronutrients and fatty acids do not operate in isolation: their neurobiological effects are synergistic, interactive, and context-dependent, meaning that the benefits of any single nutrient are substantially conditioned by the adequacy of the broader dietary matrix in which it is consumed. Consistent with this, emerging evidence supports an association between overall dietary pattern quality and adolescent mental health and well-being. 

Higher adherence to Mediterranean-style dietary patterns, characterised by abundant fruits, vegetables, whole grains, legumes, fish, and olive oil, has been associated with reduced symptoms of anxiety and depression in adolescent populations, with proposed mechanisms including attenuation of systemic neuroinflammation, favourable modulation of the gut-brain axis, enhanced antioxidant status, and improved tryptophan-kynurenine metabolism.^2,3

Conversely, diets dominated by ultra-processed, energy-dense, and micronutrient-poor foods are associated with greater internalising and externalising behavioural symptoms and poorer cognitive trajectories.¹ Taken together, this evidence underscores a compelling case for shifting the focus of adolescent nutritional policy and practice from single-nutrient supplementation toward the promotion of diverse, nutrient-dense dietary patterns that provide the full complement of brain-supportive nutrients in their naturally occurring, synergistic context.^1,7

Healthcare professionals are uniquely positioned to operationalise this shift at the individual level: through systematic nutritional screening at routine adolescent health contacts; targeted biochemical assessment of micronutrient status where indicated; delivery of adolescent-centred, family-inclusive dietary counselling using motivational interviewing and goal-directed behaviour change techniques; and timely referral to registered dieticians or specialist services for complex presentations.

In contexts where food insecurity and structural barriers constrain dietary choice, clinicians must further advocate for enabling food environments,  including school feeding programmes, nutrition education, and community-level food systems interventions,  that support adolescents in translating nutritional knowledge into sustained dietary behaviour change.^5,4 

References 

1. Brkić, D., Concetti, C., Rémond Derbez, N., & Hauser, J. (2026). Relationship between nutrition, brain, cognition, learning, and behavior in school age children. Nutrition Reviews. [academic.oup.com]
2. Dutta, S. S. (2026). Eating a Mediterranean diet may lower anxiety symptoms in teens. Nutrients. [news-medical.net]
3. López Sebastiani, V., Quiroz Cornejo, K. V., Arellano Salazar, M. P., Monje Bolivar, F., & Samillan, V. J. (2026). Micronutrient balance and brain function. Frontiers in Molecular Biosciences. [pmc.ncbi.nlm.nih.gov]
4. MacBrain Research Team. (2024). Nutrition’s impact on adolescent brain function and academic performance. [macbrain.org]
5. World Health Organisation. (2018). Guideline: implementing effective actions for improving adolescent nutrition. [who.int]
6. Young, H. A., Gaylor, C. M., Brennan, A., McIntosh, A., & Griffiths, A. R. (2026). Diet and the developing brain. Advances in Nutrition. [advances.n...rition.org]
7. Nestlé Nutrition Institute. (2026). Nutritional influences on brain, behaviour, and growth trajectories in school age children. [The Nest 5...Children_0 | PDF]