Nutrition Education Program and Physical Activity Improve the Adherence to the Mediterranean Diet: Impact on Inflammatory Biomarker Levels in Healthy Adolescents From the DIMENU Longitudinal Study

Abstract

Adherence to Mediterranean diet (MD) and physical activity (PA) in adolescence represent powerful indicators of healthy lifestyles in adulthood. The aim of this longitudinal study was to investigate the impact of nutrition education program (NEP) on the adherence to the MD and on the inflammatory status in healthy adolescents, categorized into three groups according to their level of PA (inactivity, moderate intensity, and vigorous intensity). As a part of the DIMENU (Dieta Mediterranea & Nuoto) study, 85 adolescents (aged 14-17 years) participated in the nutrition education sessions provided by a team of nutritionists and endocrinologists at T0. All participants underwent anthropometric measurements, bio-impedentiometric analysis (BIA), and measurements of inflammatory biomarkers such as ferritin, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels. Data were collected at baseline (T0) and 6 months after NEP (T1). To assess the adherence to the MD, we used KIDMED score. In our adolescents, we found an average MD adherence, which was increased at T1 compared with T0 (T0: 6.03 ± 2.33 vs. T1: 6.96 ± 2.03, p = 0.002), with an enhanced percentage of adolescents with optimal (≥8 score) MD adherence over the study period (T0: 24.71% vs. T1: 43.52%, p = 0.001). Interestingly, in linear mixed-effects models, we found that NEP and vigorous-intensity PA levels independently influenced KIDMED score (β = 0.868, p < 0.0001 and β = 1.567, p = 0.009, respectively). Using ANOVA, NEP had significant effects on serum ferritin levels (p < 0.001), while either NEP or PA influenced ESR (p = 0.035 and 0.002, respectively). We also observed in linear mixed-effects models that NEP had a negative effect on ferritin and CRP (β = -14.763, p < 0.001 and β = -0.714, p = 0.02, respectively). Our results suggest the usefulness to promote healthy lifestyle, including either nutrition education interventions, or PA to improve MD adherence and to impact the inflammatory status in adolescence as a strategy for the prevention of chronic non-communicable diseases over the entire lifespan.

Keywords: C-reactive protein; Mediterranean diet; body composition parameters; ferritin; healthy lifestyle; physical activity.

Figure 1

Compliance with items from KIDMED test according to the three physical activity (PA) groups (PAi: inactive; PAm: moderate; PAv: vigorous) at baseline (T0) and after 6 months (T1). The radar chart plots the values of each item of Mediterranean diet score along a separate axis that starts in the center of the chart (0% compliance) and ends at the outer ring (100% compliance). KIDMED score is presented as Mean ± SD; statistical differences were evaluated by two-way repeated-measures ANOVA. NEP, Nutrition Education Program.

Figure 2

Correlations between interleukin-10 and interleukin-1β, interleukin-6, or tumor necrosis factor (TNF)-α in all sample at baseline (T0) and after 6 months (T1). Association of interleukin (IL)-10 with IL-1β (A,D), IL-6 (B,E), and TNF-α (C,F) in all samples at baseline (T0) and after 6 months (T1) were analyzed by Spearman's correlation test. For each linear regression graph, the linear equation (Y), the correlation coefficient (r), and the statistical significance (p) are reported.