Mediterranean Diet and Cardiometabolic Biomarkers in Children and Adolescents: A Systematic Review and Meta-Analysis

Importance: No prior systematic review and meta-analysis has specifically verified the association of Mediterranean diet (MedDiet)-based interventions with biomarkers of cardiometabolic health in children and adolescents. Objective: To review and analyze the randomized clinical trials (RCTs) that assessed the effects of MedDiet-based interventions on biomarkers of cardiometabolic health among children and adolescents. Data Sources: Four electronic databases were searched (PubMed, Cochrane Library, Web of Science, and Scopus) from database inception to April 25, 2024. Study Selection: Only RCTs investigating the effect of interventions promoting the MedDiet on cardiometabolic biomarkers (ie, systolic blood pressure [SBP], diastolic blood pressure [DBP], triglycerides [TGs], total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], glucose, insulin, and homeostatic model assessment for insulin resistance [HOMA-IR]) among children and adolescents (aged ≤18 years) were included. Data Extraction and Synthesis: A systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data were extracted from the studies by 2 independent reviewers. Results across studies were summarized using random-effects meta-analysis. Main Outcome and Measures: The effect size of each trial was computed by unstandardized mean differences (MDs) of changes in biomarker levels (ie, SBP, DBP, TGs, TC, HDL-C, LDL-C, glucose, insulin, HOMA-IR) between the intervention and the control groups. The quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations approach. Results: Nine RCTs were included (mean study duration, 17 weeks; range, 8-40 weeks). These studies involved 577 participants (mean age, 11 years [range, 3-18 years]; 344 girls [59.6%]). Compared with the control group, the MedDiet-based interventions showed a significant association with reductions in SBP (mean difference, -4.75 mm Hg; 95% CI, -8.97 to -0.52 mm Hg), TGs (mean difference, -16.42 mg/dL; 95% CI, -27.57 to -5.27 mg/dL), TC (mean difference, -9.06 mg/dL; 95% CI, -15.65 to -2.48 mg/dL), and LDL-C (mean difference, -10.48 mg/dL; 95% CI, -17.77 to -3.19 mg/dL) and increases in HDL-C (mean difference, 2.24 mg/dL; 95% CI, 0.34-4.14 mg/dL). No significant associations were observed with the other biomarkers studied (ie, DBP, glucose, insulin, and HOMA-IR). Conclusions and Relevance: These findings suggest that MedDiet-based interventions may be useful tools to optimize cardiometabolic health among children and adolescents.