School-based physical activity interventions: which intervention characteristics are associated with participation and retention? A meta-analysis.

OBJECTIVE: Many school-based intervention studies are conducted to increase students' physical activity (PA). Recruitment and retention problems potentially impact the robustness of RCT findings. We conducted a meta-analysis to summarize recruitment and retention rates in long-term secondary school-based PA intervention studies and examined associated participant and intervention characteristics. METHODS: Web of Science, Pubmed, Medline, and PsychInfo were searched until March 20th 2023. We included studies on secondary school-based PA interventions ≥12 weeks, aimed at typically developing adolescents. We abstracted number of schools and students invited, randomized, and participating at follow-up to calculate pooled recruitment and retention rates; participant and intervention characteristics were abstracted to execute subgroup or meta-regression analyses. RESULTS: Recruitment rates were 51% for invited schools and 80% for invited students, the retention for schools was almost 100% and for students 91%. Interventions with fixed and flexible components, executed in Asia and South America, and from later publication years had higher student recruitment rates. Students' retention rates were lower for interventions which had flexible components, were theory/model-based, used an accelerometer, had a longer intervention duration, and included more females. CONCLUSION: Recruitment and retention rates in school-based PA interventions are high. Some participant and intervention characteristics influence these rates: flexibility of the intervention, theory/model-based intervention, accelerometer use, intervention duration, continent, and number of females. Researchers should consider these characteristics in intervention development to achieve optimal balance between intervention effectiveness, recruitment, and retention.

Effect of one year krill oil supplementation on depressive symptoms and self-esteem of Dutch adolescents: A randomized controlled trial.

INTRODUCTION: Observational studies have shown a relationship between omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) and depression in adolescents. However, n-3 LCPUFA supplementation studies investigating the potential improvement in depressive feelings in adolescents from the general population are missing. METHODS: A one-year double-blind, randomized, placebo controlled krill oil supplementation trial was conducted in two cohorts. Cohort I started with 400 mg eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) or placebo, after three months this increased to 800 mg EPA and DHA per day, whilst cohort II started with this higher dose. Omega-3 Index (O3I) was monitored via finger-prick blood measurements. At baseline, six and 12 months participants completed the Centre for Epidemiologic Studies Depression Scale (CES-D) and the Rosenberg Self Esteem questionnaire (RSE). Adjusted mixed models were run with treatment allocation/O3I as predictor of CES-D and RSE scores. RESULTS: Both intention-to-treat and assessing the change in O3I analyses did not show significant effects on CES-D or RSE scores. CONCLUSION: There is no evidence for less depressive feelings, or higher self-esteem after one year of krill oil supplementation. However, due to a lack of adherence and drop-out issues, these results should be interpreted with caution.

Correction to: Exploring the association between whole blood Omega-3 Index, DHA, EPA, DPA, AA and n-6 DPA, and depression and self-esteem in adolescents of lower general secondary education.

The original version of this article unfortunately contained a mistake. Title was incorrect.

[Nutrition and mental disorders during the life span: an overview of scientific evidence]. / Voeding bij psychische aandoeningen gedurende de levensloop; een overzicht van de evidentie.

BACKGROUND: Nutritional interventions are scarcely used in the prevention and treatment of mental disorders.
AIM: To summarize scientific evidence on the relation between nutrition and mental health, across the life span.
METHOD: An overview of the literature based on recent knowledge syntheses, meta-analyses and original studies.
RESULTS: Healthy dietary patterns are associated with a lower risk for depressive symptoms among adults and potentially also among children and adolescents. Dietary interventions can be effective in reducing depressive symptoms among high-risk groups and can have a beneficial effect in the treatment of depression. Meta-analyses of randomised studies have shown that omega-3 fatty acid supplements can be of added value in the treatment of adhd in children and of depression in adults.
CONCLUSION: Promotion of healthy dietary patterns in line with National guidelines for healthy diets is important in the entire spectrum from good mental health to a chronic disorder. More attention for improving healthy dietary patterns among patients with mental disorders can lead to important health gains.

Exploring the association between whole blood Omega-3 Index, DHA, EPA, DHA, AA and n-6 DPA, and depression and self-esteem in adolescents of lower general secondary education.

PURPOSE: Depression is common in adolescents and long-chain polyunsaturated fatty acids (LCPUFA) are suggested to be associated with depression. However, research in adolescents is limited. Furthermore, self-esteem has never been studied in relation to LCPUFA. The objective here was to determine associations of depression and self-esteem with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), Omega-3 Index (O3I), n-6 docosapentaenoic acid (n-6 DPA, also called Osbond acid, ObA), n-3 docosapentaenoic acid (DPA), and arachidonic acid (AA) concentrations in blood of adolescents attending lower general secondary education (LGSE). METHODS: Baseline cross-sectional data from a krill oil supplementation trial in adolescents attending LGSE with an O3I ≤ 5% were analysed using regression models built with the BayesFactor package in R. Fatty acids and O3I were determined in blood. Participants filled out the Centre for Epidemiologic Studies Depression (CES-D) scale and the Rosenberg Self-Esteem scale (RSE). RESULTS: Scores indicative of depression (CES-D ≥ 16) were found in 29.4% of the respondents. Of all fatty acids, we found extreme evidence [Bayes factor (BF) > 100] for a weak negative association between ObA and depression score [- 0.16; 95% credible interval (CI) - 0.28 to - 0.04; BF10 = 245], and substantial evidence for a weak positive association between ObA and self-esteem score (0.09; 95% CI, - 0.03 to 0.20; BF10 = 4). When all fatty acids were put in one model as predictors of CES-D or RSE, all of the 95% CI contained 0, i.e., no significant association. CONCLUSION: No evidence was found for associations of DHA, EPA and O3I with depression or self-esteem scores in LGSE adolescents with O3I ≤ 5%. The associations of higher ObA status with lower depression and higher self-esteem scores warrant more research.

Polyunsaturated fatty acid levels at birth and child-to-adult growth: Results from the MEFAB cohort.

BACKGROUND: Prenatal exposure to polyunsaturated fatty acids (PUFAs) may influence childhood growth. However, available evidence mostly derived from short-term studies is inconsistent. OBJECTIVE: To assess whether fetal PUFA exposure is associated with height and body mass index (BMI), a common measure of adiposity, from 6 months to 23 years of age. METHODS: In the MEFAB cohort, we assessed cord blood phospholipid n-3 and n-6 PUFA levels, reflecting fetal exposure in late pregnancy. For 250 (45.2% females) participants, we collected a total of 1770 (n= 802 for females) repeated growth measurements from infancy to young adulthood. We examined sex-specific associations of PUFAs with height and BMI at different developmental ages (infant: 6 months; toddler: 2 years; pre-schooler: 4 years; school-aged child: 7 years; adolescent: 12 years; and young adult: 23 years) using fractional polynomial mixed models adjusted for important covariates. RESULTS: Higher n-3 PUFA levels were associated with higher infant length in males (ß= 0.44cm [95% CI: 0.07, 0.82] per SD increase), whereas, for females, higher n-6 PUFA concentrations were associated with lower length in infancy (ß= -0.69cm [95% CI: -1.08, -0.30] per SD increase). A higher ratio of n-3 to n-6 PUFAs was associated with higher infant length in both sexes (ß= 0.40cm [95% CI: 0.01, 0.78] and 0.42cm [95% CI: 0.05, 0.79] per unit increase for males and females, respectively). These associations were not detectable later in childhood and young adulthood. No associations with BMI were found at any time point examined. CONCLUSIONS: Our findings suggest a small sex-specific influence of PUFA status at birth on length in infancy, but this does not persist in later life up to young adulthood. PUFA status at birth does not seem to affect BMI from infancy till young adulthood.

A protocol for a randomised controlled trial investigating the effect of increasing Omega-3 index with krill oil supplementation on learning, cognition, behaviour and visual processing in typically developing adolescents.

INTRODUCTION: The influence of n-3 long-chain polyunsaturated fatty acids (LCPUFA) supplementation on brain functioning is debated. Some studies have found positive effects on cognition in children with learning difficulties, elderly people with cognitive impairment and depression scores in depressed individuals. Other studies have found null or negative effects. Observational studies in adolescents have found positive associations between fish consumption (containing n-3 LCPUFAs) and academic achievement. However, intervention studies in typically developing adolescents are missing. OBJECTIVE: The goal of this study is to determine the influence of increasing Omega-3 Index on cognitive functioning, academic achievement and mental well-being of typically developing adolescents. METHODS AND DATA ANALYSIS: Double-blind, randomised, placebo controlled intervention; 264 adolescents (age 13-15 years) attending lower general secondary education started daily supplementation of 400 mg eicosapentaenoic acid and docosahexaenoic acid (EPA+DHA) in cohort I (n=130) and 800 mg EPA+DHA in cohort II (n=134) or a placebo for 52 weeks. Recruitment took place according to a low Omega-3 Index (<5%). The Omega-3 Index was monitored via a finger prick at baseline and after 3, 6 and 12 months. The supplement dose was adjusted after 3 months (placebo analogously) to reach an Omega-3 Index of 8-11%. At baseline, 6 and 12 months, a neuropsychological test battery, a number of questionnaires and a standardised math test (baseline and 12 months) were administered. School grades were collected. In a subsample, sleep quality and quantity data (n=64) and/or eye-tracking data (n=33) were collected. ETHICS AND DISSEMINATION: Food2Learn is performed according to Good Clinical Practice. All data collected are linked to participant number only. The results will be disseminated on group level to participants and schools. The results will be presented at conferences and published in peer-reviewed journals. The study is approved by the Medical Ethical Committee of Atrium-Orbis-Zuyd Hospital and is registered at the Netherlands Trial Register (NTR4082). TRIAL REGISTRATION NUMBERS: NTR4082 and NCT02240264; Pre-results.

Association between prenatal and current exposure to selected LCPUFAs and school performance at age 7.

INTRODUCTION: Long-chain polyunsaturated fatty acids (LCPUFAs) are important for brain functioning and might, thus, influence cognition and school performance. However, research investigating LCPUFAs relationships with school performance is limited. The objective of this study was to determine the association between levels of the LCPUFAs docosahexaenoic acid (DHA), arachidonic acid (AA), eicosapentaenoic acid (EPA) and n-6 docosapentaenoic acid (Osbond acid, ObA) at study entry, 22 weeks of pregnancy, 32 weeks of pregnancy, at partus, in umbilical cord plasma and child's plasma at age 7 and school performance scores at age 7. METHODS: Data from the Maastricht Essential Fatty Acid Birth cohort (MEFAB) were used for this study. Fatty acid levels of plasma phospholipids were measured in maternal blood plasma at study entry, 22 weeks of pregnancy, 32 weeks of pregnancy and partus. Childs fatty acid levels of plasma phospholipids were measured a in umbilical cord blood plasma, and in blood plasma of the child at age 7. Scores on national standardised tests for spelling, reading and arithmetic at age 7 were obtained via the school (scores were available for 149, 159 and 155 children, respectively). Associations between LCPUFA levels and school performance scores were analysed with categorical regression analyses with correction for covariates (smoking, maternal education, sex, breastfeeding, maternal intelligence, birth weight and BMI at age 7). RESULTS: Significant (p<0.001) associations between DHA level at age 7 and both reading (ß=0.158) and spelling (ß=0.146) were found. Consistent significant negative associations were observed between all maternal DHA plasma levels and arithmetic scores at age 7 (all p<0.001, all ß<-0.019). Additional significant negative associations were observed between maternal LCPUFA plasma levels at study entry and both reading and spelling scores at age 7; these associations were less consistent. CONCLUSION: Plasma DHA levels at age 7 were positively associated with reading and spelling scores at age 7. Consistent significant negative associations between maternal plasma DHA levels and arithmetic scores of the child at age 7 were found. Although this is an observational study, which cannot proof causality, the consistent negative associations observed between maternal plasma DHA levels and the arithmetic scores of the children at age 7 calls upon prudence when considering DHA supplementation during pregnancy.