Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context

Summary: Background: Omega-3 fatty acids are critical for neuropsychological functioning. Adolescence is increasingly believed to entail brain vulnerability to dietary intake. The potential benefit on adolescent neurodevelopment of consuming walnuts, a source of omega-3 alpha-linolenic acid (ALA),...

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Main Authors: Ariadna Pinar-Martí, Florence Gignac, Silvia Fernández-Barrés, Dora Romaguera, Aleix Sala-Vila, Iolanda Lázaro, Otavio T. Ranzani, Cecilia Persavento, Anna Delgado, Albert Carol, Jaume Torrent, Judith Gonzalez, Eduard Roso, Jose Barrera-Gómez, Mónica López-Vicente, Olivier Boucher, Mark Nieuwenhuijsen, Michelle C. Turner, Miguel Burgaleta, Josefina Canals, Victoria Arija, Xavier Basagaña, Emilio Ros, Jordi Salas-Salvadó, Jordi Sunyer, Jordi Julvez
Format: Article
Language:English
Published: Elsevier 2023-05-01
Series:EClinicalMedicine
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Online Access:http://www.sciencedirect.com/science/article/pii/S2589537023001311
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author Ariadna Pinar-Martí
Florence Gignac
Silvia Fernández-Barrés
Dora Romaguera
Aleix Sala-Vila
Iolanda Lázaro
Otavio T. Ranzani
Cecilia Persavento
Anna Delgado
Albert Carol
Jaume Torrent
Judith Gonzalez
Eduard Roso
Jose Barrera-Gómez
Mónica López-Vicente
Olivier Boucher
Mark Nieuwenhuijsen
Michelle C. Turner
Miguel Burgaleta
Josefina Canals
Victoria Arija
Xavier Basagaña
Emilio Ros
Jordi Salas-Salvadó
Jordi Sunyer
Jordi Julvez
author_facet Ariadna Pinar-Martí
Florence Gignac
Silvia Fernández-Barrés
Dora Romaguera
Aleix Sala-Vila
Iolanda Lázaro
Otavio T. Ranzani
Cecilia Persavento
Anna Delgado
Albert Carol
Jaume Torrent
Judith Gonzalez
Eduard Roso
Jose Barrera-Gómez
Mónica López-Vicente
Olivier Boucher
Mark Nieuwenhuijsen
Michelle C. Turner
Miguel Burgaleta
Josefina Canals
Victoria Arija
Xavier Basagaña
Emilio Ros
Jordi Salas-Salvadó
Jordi Sunyer
Jordi Julvez
author_sort Ariadna Pinar-Martí
collection DOAJ
description Summary: Background: Omega-3 fatty acids are critical for neuropsychological functioning. Adolescence is increasingly believed to entail brain vulnerability to dietary intake. The potential benefit on adolescent neurodevelopment of consuming walnuts, a source of omega-3 alpha-linolenic acid (ALA), remains unclear. Methods: We conducted a 6-month multi-school-based randomised controlled nutrition intervention trial to assess whether walnut consumption has beneficial effects on the neuropsychological and behavioural development of adolescents. The study took place between 04/01/2016 and 06/30/2017 in twelve different high schools in Barcelona, Spain (ClinicalTrials.gov Identifier: NCT02590848). A total of 771 healthy teenagers aged 11–16 years were randomised into two equal groups (intervention or control). The intervention group received 30 g/day of raw walnut kernels to be incorporated into their diet for 6 months. Multiple primary endpoints concerning neuropsychological (working memory, attention, fluid intelligence, and executive function) and behavioural (socio-emotional and attention deficit hyperactivity disorder [ADHD] symptoms) development were assessed at baseline and after intervention. Red blood cell (RBC) ALA status was determined at baseline and 6 months as a measure of compliance. Main analyses were based on intention-to-treat using a linear mixed-effects model. A per-protocol effect of the intervention was analysed using inverse-probability weighting to account for post-randomisation prognostic factors (including adherence) using generalised estimating equations. Findings: In intention-to-treat analyses, at 6 months there were no statistically significant changes between the intervention and control groups for all primary endpoints. RBC ALA (%) significantly increased only in the intervention group, coefficient = 0.04 (95% Confidence Interval (CI) = 0.03, 0.06; p < 0.0001). The per-protocol (adherence-adjusted) effect on improvement in attention score (hit reaction time variability) was −11.26 ms (95% CI = −19.92, −2.60; p = 0.011) for the intervention group as compared to the control group, improvement in fluid intelligence score was 1.78 (95% CI = 0.90, 2.67; p < 0.0001), and reduction of ADHD symptom score was −2.18 (95% CI = −3.70, −0.67; p = 0.0050). Interpretation: Our study suggested that being prescribed eating walnuts for 6 months did not improve the neuropsychological function of healthy adolescents. However, improved sustained attention, fluid intelligence, and ADHD symptoms were observed in participants who better complied with the walnut intervention. This study provides a foundation for further clinical and epidemiological research on the effect of walnuts and ALA on neurodevelopment in adolescents. Funding: This study was supported by Instituto de Salud Carlos III through the projects ‘CP14/00108, PI16/00261, PI21/00266’ (co-funded by European Union Regional Development Fund ‘A way to make Europe’). The California Walnut Commission (CWC) has given support by supplying the walnuts for free for the Walnuts Smart Snack Dietary Intervention Trial.
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spelling doaj.art-a1dde5e1c28f43a8a90010c5e1cce20c2023-04-08T05:14:13ZengElsevierEClinicalMedicine2589-53702023-05-0159101954Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in contextAriadna Pinar-Martí0Florence Gignac1Silvia Fernández-Barrés2Dora Romaguera3Aleix Sala-Vila4Iolanda Lázaro5Otavio T. Ranzani6Cecilia Persavento7Anna Delgado8Albert Carol9Jaume Torrent10Judith Gonzalez11Eduard Roso12Jose Barrera-Gómez13Mónica López-Vicente14Olivier Boucher15Mark Nieuwenhuijsen16Michelle C. Turner17Miguel Burgaleta18Josefina Canals19Victoria Arija20Xavier Basagaña21Emilio Ros22Jordi Salas-Salvadó23Jordi Sunyer24Jordi Julvez25Institut d'Investigació Sanitària Pere Virgili (IISPV), Clinical and Epidemiological Neuroscience Group (NeuroÈpia), 43204 Reus (Tarragona), Catalonia, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain; ISGlobal, Barcelona, SpainUniversitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain; ISGlobal, Barcelona, SpainISGlobal, Barcelona, Spain; Agència de Salut Pública de Barcelona, Pl. Lesseps 1, 08023, Barcelona, SpainInstitut d'Investigació Sanitària Pere Virgili (IISPV), Clinical and Epidemiological Neuroscience Group (NeuroÈpia), 43204 Reus (Tarragona), Catalonia, Spain; ISGlobal, Barcelona, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Hospital Universitari Son Espases, Palma de Mallorca, Spain; Consorcio CIBER, M.P. Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III (ISCIII), Madrid, SpainThe Fatty Acid Research Institute, Sioux Falls, SD, USA; Cardiovascular Risk and Nutrition, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Catalonia, SpainCardiovascular Risk and Nutrition, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Catalonia, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainISGlobal, Barcelona, SpainCentre de Recherche du Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, CanadaISGlobal, Barcelona, SpainUniversitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain; ISGlobal, Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III (ISCIII), Madrid, SpainUniversity of Barcelona, Barcelona, SpainNutrition and Public Health Unit, Research Group on Nutrition and Mental Health (NUTRISAM), Faculty of Medicine and Health Science, Universitat Rovira I Virgili, 43201 Reus, SpainNutrition and Public Health Unit, Research Group on Nutrition and Mental Health (NUTRISAM), Faculty of Medicine and Health Science, Universitat Rovira I Virgili, 43201 Reus, SpainUniversitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain; ISGlobal, Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III (ISCIII), Madrid, SpainLipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Biomedical Research Institute August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, SpainConsorcio CIBER, M.P. Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III (ISCIII), Madrid, Spain; Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari Sant Joan de Reus, 43204 Reus, Catalonia, Spain; Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, Unitat de Nutrició Humana, Reus, SpainUniversitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain; ISGlobal, Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III (ISCIII), Madrid, SpainInstitut d'Investigació Sanitària Pere Virgili (IISPV), Clinical and Epidemiological Neuroscience Group (NeuroÈpia), 43204 Reus (Tarragona), Catalonia, Spain; ISGlobal, Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III (ISCIII), Madrid, Spain; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA; Corresponding author. Institut d'Investigació Sanitària Pere Virgili (IISPV), NeuroÈpia Group, Hospital Universitari Sant Joan de Reus, 43204 Reus (Tarragona), Catalonia, Spain.Summary: Background: Omega-3 fatty acids are critical for neuropsychological functioning. Adolescence is increasingly believed to entail brain vulnerability to dietary intake. The potential benefit on adolescent neurodevelopment of consuming walnuts, a source of omega-3 alpha-linolenic acid (ALA), remains unclear. Methods: We conducted a 6-month multi-school-based randomised controlled nutrition intervention trial to assess whether walnut consumption has beneficial effects on the neuropsychological and behavioural development of adolescents. The study took place between 04/01/2016 and 06/30/2017 in twelve different high schools in Barcelona, Spain (ClinicalTrials.gov Identifier: NCT02590848). A total of 771 healthy teenagers aged 11–16 years were randomised into two equal groups (intervention or control). The intervention group received 30 g/day of raw walnut kernels to be incorporated into their diet for 6 months. Multiple primary endpoints concerning neuropsychological (working memory, attention, fluid intelligence, and executive function) and behavioural (socio-emotional and attention deficit hyperactivity disorder [ADHD] symptoms) development were assessed at baseline and after intervention. Red blood cell (RBC) ALA status was determined at baseline and 6 months as a measure of compliance. Main analyses were based on intention-to-treat using a linear mixed-effects model. A per-protocol effect of the intervention was analysed using inverse-probability weighting to account for post-randomisation prognostic factors (including adherence) using generalised estimating equations. Findings: In intention-to-treat analyses, at 6 months there were no statistically significant changes between the intervention and control groups for all primary endpoints. RBC ALA (%) significantly increased only in the intervention group, coefficient = 0.04 (95% Confidence Interval (CI) = 0.03, 0.06; p < 0.0001). The per-protocol (adherence-adjusted) effect on improvement in attention score (hit reaction time variability) was −11.26 ms (95% CI = −19.92, −2.60; p = 0.011) for the intervention group as compared to the control group, improvement in fluid intelligence score was 1.78 (95% CI = 0.90, 2.67; p < 0.0001), and reduction of ADHD symptom score was −2.18 (95% CI = −3.70, −0.67; p = 0.0050). Interpretation: Our study suggested that being prescribed eating walnuts for 6 months did not improve the neuropsychological function of healthy adolescents. However, improved sustained attention, fluid intelligence, and ADHD symptoms were observed in participants who better complied with the walnut intervention. This study provides a foundation for further clinical and epidemiological research on the effect of walnuts and ALA on neurodevelopment in adolescents. Funding: This study was supported by Instituto de Salud Carlos III through the projects ‘CP14/00108, PI16/00261, PI21/00266’ (co-funded by European Union Regional Development Fund ‘A way to make Europe’). The California Walnut Commission (CWC) has given support by supplying the walnuts for free for the Walnuts Smart Snack Dietary Intervention Trial.http://www.sciencedirect.com/science/article/pii/S2589537023001311Adolescent healthCognitive functionNeuropsychologyRandomised nutritional interventionPublic healthWalnut intake
spellingShingle Ariadna Pinar-Martí
Florence Gignac
Silvia Fernández-Barrés
Dora Romaguera
Aleix Sala-Vila
Iolanda Lázaro
Otavio T. Ranzani
Cecilia Persavento
Anna Delgado
Albert Carol
Jaume Torrent
Judith Gonzalez
Eduard Roso
Jose Barrera-Gómez
Mónica López-Vicente
Olivier Boucher
Mark Nieuwenhuijsen
Michelle C. Turner
Miguel Burgaleta
Josefina Canals
Victoria Arija
Xavier Basagaña
Emilio Ros
Jordi Salas-Salvadó
Jordi Sunyer
Jordi Julvez
Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context
EClinicalMedicine
Adolescent health
Cognitive function
Neuropsychology
Randomised nutritional intervention
Public health
Walnut intake
title Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context
title_full Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context
title_fullStr Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context
title_full_unstemmed Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context
title_short Effect of walnut consumption on neuropsychological development in healthy adolescents: a multi-school randomised controlled trialResearch in context
title_sort effect of walnut consumption on neuropsychological development in healthy adolescents a multi school randomised controlled trialresearch in context
topic Adolescent health
Cognitive function
Neuropsychology
Randomised nutritional intervention
Public health
Walnut intake
url http://www.sciencedirect.com/science/article/pii/S2589537023001311
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