Effects of protein-rich multi-nutrient intervention on bone mineralization and development: insights from a randomized controlled trial in prepubertal children and a zebrafish experiment

Abstract

High-protein foods and physical activity are crucial for bone growth in early life. This study first examined whether a protein-rich multi-nutrient intervention combined with rope-skipping training could prevent bone loss during winter in prepubertal children. A 10 week randomized controlled trial involving 120 children aged 9–12 years in rural northwestern China was conducted. Participants were assigned to a treatment group (protein-rich multi-nutritional drink plus rope-skipping training) or a control group (rope-skipping training only). Forearm bone mineral density (BMD) was measured at the baseline and week 10 of the trial, along with serum calcium, parathyroid hormone (PTH), insulin-like growth factor 1 (IGF-1), and bone turnover biomarkers. Second, we estimated the effects of three protein sources enriched in the drink, milk protein concentrates (MPC), collagen peptides (CP), and whey protein hydrolysates (WPH), on zebrafish backbone development. In children, BMD decreased in both groups, but the treatment group showed a smaller reduction and a positive intervention effect (relative change: 0.023 g cm⁻², P = 0.037). The treatment group also had a smaller increase in PTH (relative change: −8.53 ng L⁻¹, P = 0.012) and a smaller decrease in IGF-1 (relative change: 20.75 ng mL⁻¹, P = 0.076). No significant differences were found in bone turnover biomarkers. In zebrafish, MPC, CP, and WPH individually and synergistically promoted bone growth without adverse effects, as shown by dose-dependent increases in the backbone fluorescence intensity. These findings suggest that protein-rich multi-nutrient supplementation combined with rope-skipping training could prevent bone loss in prepubertal children during winter, potentially through changes in serum PTH and IGF-1, and highlight the synergistic effects of these proteins on bone development.