Mediterranean Diet Interventions Show Positive Impact on Cardiometabolic Health in Youth: A Meta-Analysis

Interventions encouraging adherence to the Mediterranean diet were modestly linked to lower systolic blood pressure (SBP), triglycerides (TGs), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL C) levels, as well as higher levels of high-density lipoprotein cholesterol (HDL C) in youth, the researchers reported in JAMA Network Open.

The Mediterranean diet, characterized by high consumption of fruits, vegetables, whole grains, legumes, nuts, and healthy fats, particularly olive oil, has been associated with reduced risks of chronic diseases in adults. No systematic review and meta-analysis to date have specifically confirmed the association between Mediterranean diet (MedDiet) interventions and cardiometabolic health biomarkers in children and adolescents.

Against the above background, José Francisco López-Gil, One Health Research Group, Universidad de Las Américas, Quito, Ecuador, and colleagues aimed to review and analyze the randomized clinical trials (RCTs) that evaluated the effects of MedDiet-based interventions on biomarkers of cardiometabolic health among children and adolescents.

For this purpose, the researchers searched four electronic databases from the database inception to April 25, 2024. It included RCTs investigating the effect of interventions promoting the MedDiet on cardiometabolic biomarkers (SBP, diastolic blood pressure, TGs, TC, HDL C, LDL C, insulin, glucose, and homeostatic model assessment for insulin resistance [HOMA-IR]) among children and adolescents (aged ≤18 years).

This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent reviewers extracted data from the selected studies, and the results were summarized using a random-effects meta-analysis.

The effect size for each trial was determined by calculating unstandardized mean differences (MDs) in biomarker levels, including systolic blood pressure (SBP), diastolic blood pressure (DBP), triglycerides (TGs), total cholesterol (TC), HDL cholesterol (HDL-C), LDL cholesterol (LDL-C), glucose, insulin, and HOMA-IR, between intervention and control groups. The quality of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach.

Based on the study, the researchers reported the following findings:

• Nine RCTs were included (mean study duration, 17 weeks). These studies involved 577 participants (mean age, 11 years; 59.6% girls).
• Compared with the control group, the MedDiet-based interventions showed a significant association with reductions in SBP (mean difference, −4.75 mm Hg), TGs (mean difference, −16.42 mg/dL), TC (mean difference, −9.06 mg/dL), and LDL-C (mean difference, −10.48 mg/dL) and increases in HDL-C (mean difference, 2.24 mg/dL).
• There were no significant associations with the other biomarkers studied (i.e., DBP, glucose, insulin, and HOMA-IR).

"These findings highlight the critical need to encourage healthy eating habits among youth, as such practices can significantly enhance cardiometabolic health from an early age. Specifically, Mediterranean diet-based interventions in various settings—such as schools and hospitals—could serve as effective strategies for improving cardiometabolic health in young populations," the researchers concluded.

Reference:

López-Gil JF, García-Hermoso A, Martínez-González MÁ, Rodríguez-Artalejo F. Mediterranean Diet and Cardiometabolic Biomarkers in Children and Adolescents: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024;7(7):e2421976. doi:10.1001/jamanetworkopen.2024.21976