New evidence highlights the importance of diet in adolescent brain health, a key life stage in which cognition is influenced not only by nutritional factors but also by lifestyle habits and psychological wellbeing. Two studies conducted by the Southern Catalonia Biomedical Research Institute – IRBCatSud (formerly IISPV), in collaboration with the Barcelona Institute for Global Health (ISGlobal) —a centre supported by the “la Caixa” Foundation— and published in the journal Nutrients, explore how the Mediterranean diet and blood fatty acids are associated with different cognitive functions in adolescents from Catalonia. Nearly 630 young people took part in both studies.
The study The Association Between the Mediterranean Diet and Fatty Acids in Red Blood Cells of Spanish Adolescents examines the relationship between adherence to the Mediterranean diet -based on fruit, vegetables, legumes, olive oil, nuts and fish- and the types of fats found in adolescents’ blood, which are an objective indicator of dietary habits. The results show that following this diet helps the body absorb essential nutrients needed for balance and proper brain function. From a biological perspective, because the diet is rich in omega‑3 fatty acids, it contributes to neuronal balance and helps prevent oxidative damage. According to the NeuroÈpia research group at IRB CatSud, this type of diet may support a healthier fat composition from early stages of life.
Omega‑3 linked to better cognitive function
A second study, entitled Red Blood Cell Fatty Acid Patterns and Cognitive Functions in Adolescents, focuses on the relationship between blood fats and different cognitive abilities, such as reasoning, memory and decision‑making. The results show that adolescents with higher omega‑3 levels achieve better results in reasoning tasks and in some aspects of decision‑making. These abilities, which develop rapidly during adolescence, are essential for cognitive functioning and can be influenced by both biological factors and lifestyle. The findings support the idea that omega‑3 fatty acids -mainly found in oily fish, nuts and some vegetable oils- may play an important role in cognitive development during this stage of life.
Emotional wellbeing, lifestyle and cognitive function
Beyond nutrition, brain development during adolescence is also influenced by psychological wellbeing and lifestyle habits. A third IRB CatSud‑ISGlobal study published in Frontiers in Psychology –Exploring the interplay of neuropsychological functions, psychological wellbeing, and lifestyle through principal component analysis: a comprehensive study– reports that lower emotional wellbeing and alcohol or tobacco use are associated with more ADHD symptoms, while physical activity is positively linked to executive functions related to decision‑making and emotional regulation. This study included a sample of 523 adolescents from Catalonia.
According to the study author, Nicolas Ayala‑Aldana, and the principal investigator of the NeuroÈpia group, Jordi Julvez, these findings highlight the importance of promoting healthy dietary habits and lifestyles during adolescence in order to support cognitive development. Although these are observational studies, the results provide useful evidence for designing health promotion strategies that combine nutrition with other key lifestyle factors.
References
Ayala-Aldana N, Pinar-Martí A, Ruiz-Rivera M, Lázaro I, Sala-Vila A, Healy DR, Contreras-Rodriguez O, Casanova J, Sola-Valls N, Vrijheid M, Julvez J. Red Blood Cell Fatty Acid Patterns and Cognitive Functions in Adolescents: A Pooled Analyses with Two Cohort Study Data Sets. Nutrients. 2025 Nov 5;17(21):3483. doi: 10.3390/nu17213483. PMID: 41228554; PMCID: PMC12609364.
Ayala-Aldana N, Lafuente D, Lázaro I, Pinar-Martí A, Manidis A, Bernardo-Castro S, Fernandez-Barres S, Healy DR, Vrijheid M, Contreras-Rodríguez O, Sala-Vila A, Julvez J. The Association Between the Mediterranean Diet and Fatty Acids in Red Blood Cells of Spanish Adolescents. Nutrients. 2025 Sep 6;17(17):2888. doi: 10.3390/nu17172888. PMID: 40944276; PMCID: PMC12430225.
Ayala-Aldana, N., Ruiz-Rivera, M., Pinar-Martí, A., López-Vicente, M., Contreras-Rodríguez, O., & Julvez, J. (2025). Exploring the interplay of neuropsychological functions, psychological wellbeing, and lifestyle through principal component analysis: a comprehensive study. Frontiers in psychology, 16, 1692251. doi: 10.3389/fpsyg.2025.1692251. PMID: 41488935; PMCID: PMC12756113.
A new study by IRB CatSud and ISGlobal links teenagers’ nutrition with emotional wellbeing, cognitive performance, and long‑term decision‑making
Adolescence is a key period for brain development, and eating habits play an essential role in this process. A new study led by the Institut de Recerca Biomèdica Catalunya Sud (Southern Catalonia Biomedical Reseach Institute – IRB CatSud, formerly IISPV), includes the participation of the Barcelona Institute for Global Health (ISGlobal), a centre supported by the “la Caixa” Foundation, shows that eating ultra‑processed foods is linked to more emotional and behavioural difficulties. On the other hand, following the Mediterranean diet is associated with better executive function. The study, titled Dietary Patterns and Neuropsychological Function in Adolescents: A Cross-sectional and Longitudinal Study, has been published in BMC Medicine.
The study, carried out by the Clinical and Epidemiological Neuroscience Research Group (NeuroÈpia) at IRB CatSud. The research analyses data from a sample of 653 adolescents aged 12 to 16 from the metropolitan area of Barcelona (Smart-Snack study). It highlights the importance of nutrition during adolescence, a stage where the brain is still developing, especially the prefrontal cortex, which is involved in decision‑making and impulse control.
Eating habits were assessed using food‑frequency questionnaires that measured adherence to the Mediterranean diet and the intake of ultra‑processed foods. Neuropsychological function was evaluated through standardised computerised tests that measured attention, working memory, fluid intelligence, decision‑making, and emotional recognition. Behavioural and emotional outcomes were also assessed using validated questionnaires.
Opposite effects on the teen brain
The results show clear differences between the two eating patterns. According to Alexios Manidis, the lead researcher, a higher intake of ultra‑processed foods—such as sugary drinks, industrial pastries, and ultra-processed meats—is linked to poorer performance in emotional recognition and sustained attention. Teenagers who consume more ultra‑processed foods also report more symptoms of anxiety and depression, as well as more behavioural problems.
In contrast, greater adherence to the Mediterranean diet—rich in fruits, vegetables, legumes, and olive oil—is linked to fewer behavioural problems and better scores in executive attention.
However, in the six-month follow-up, only initial ultra-processed food consumption showed longitudinal associations with internalizing symptoms and decision-making, while Mediterranean diet adherence showed no longitudinal effects. “This may suggest that Mediterranean diet benefits require ongoing adherence, while the effects of ultra-processed foods may be more persistent,” comments Manidis, reinforcing the importance of maintaining healthy habits consistently.
Objective validation through biomarkers
The study also analysed urinary biomarkers in a subsample of 257 participants. The results show that adolescents who consume more ultra‑processed foods have fewer compounds from plant‑based foods and more compounds linked to food processing, confirming the reliability of dietary questionnaires.
Christopher Papandreou, Assistant Professor at the Hellenic Mediterranean University (Crete, Greece) and senior co-author of the study, notes that “teenagers’ diets are shifting towards ultra-processed foods” and warns that this change “may be contributing to the rise in mental health problems among young people”.
Jordi Julvez, head researcher of the NeuroÈpia Research Group at the IRB CatSud and ISGlobal, reminds us that “adolescence is a period of great brain reorganisation” and explains that diet “can influence how teenagers regulate their emotions and make complex decisions”.
The researchers conclude that future strategies, such as replacing processed snacks in schools with nutrient‑dense options like nuts and fresh fruit, could be effective in improving emotional regulation and cognitive function in the long term.
Bibliographic reference of the study
Manidis, A., Ayala-Aldana, N., Bernardo-Castro, S., Pinar-Martí, A., Galkina, P., Fernández-Barrés, S., Ramirez-Carrasco, P., Lamuela-Raventós, R. M., Papandreou, C., & Julvez, J. (2026). Dietary patterns and neuropsychological function in adolescents: a cross-sectional and longitudinal study. BMC Medicine, 10.1186/s12916-026-04658-6. Advance online publication. https://doi.org/10.1186/s12916-026-04658-6