Protein-enriched soup and weekly exercise improve muscle health: A randomized trial in mid-to-old age with inadequate protein intake.

Abstract

Prior research has highlighted the synergistic impact of protein supplementation on muscle function post-exercise in adults; however, evidence supporting the combined effects were less robust and inconsistent on those with protein insufficiency. This investigation aims to explore efficacy of protein-enriched soup coupled with exercise on muscle health and metabolism in middle-aged and older adults with suboptimal protein intake. An open-label, 12-week, randomized controlled trial involving participants with insufficient protein intake (<1.0g/kg/day) was done. The intervention group consumed protein-enriched soup (24-30g protein daily) and 1-h weekly exercise, while controls received health education. Assessments included laboratory tests, functional assessments, and body composition. In this trial, 97 out of 100 randomized participants (mean age: 64.65±4.84years, 81.8% female) completed the study (47 in intervention group and 50 in control group). Compared results of baselines, at 1 and 3months of intervention, significant improvements in waist circumference (83.48±10.22 vs. 82.5±9.88 vs. 82.37±9.42cm, P for trend=0.046), 6-min walking distance (525.65±58.46 vs. 534.47±51.87 vs. 552.02±57.66m, P for trend=0.001), five-time sit-to-stand time (7.63±1.63 vs. 6.81±1.8 vs. 6.4±1.42s, P for trend <0.001), grip strength (26.74±6.54 vs. 27.53±6.99 vs. 28.52±7.09kg, P for trend <0.001), and MNA score (26.8±2.14 vs. 27.73±1.74 vs. 27.55±1.72, P for trend <0.001) were discerned within the intervention group. The intervention demonstrated a significant reduction in serum triglyceride (105.32±49.84 vs. 101.36±42.58 vs. 93.43±41.49mg/dL, P for trend=0.023), increased HDL-C (60.04±16.21 vs. 60±17.37 vs. 62.55±18.27mg/dL, P for trend=0.02), and DHEA-S levels (97.11±54.39 vs. 103.39±56.75 vs. 106.83±60.56μg/dL, P for trend=0.002). Serum myostatin did not differ in both groups, but serum leptin levels significantly increased (9118.88±5811.68 vs. 11508.97±7151.08 vs. 11220.80±7190.71pg/mL, P for trend=0.016) in controls. The intervention group showed greater improvements in 6min walking distance (β=0.71, 95% CI: 6.88 to 40.79, P=0.006), five-time sit-to-stand test (β=-0.87, 95% CI: -1.59 to -0.15, P=0.017), MNA score (β=0.96, 95% CI: 0.20 to 1.71, P=0.013), serum triglycerides (β=-15.01, 95% CI: -27.83 to -2.20, P=0.022), LDL-C (β=-9.23, 95% CI: -16.98 to -1.47, P=0.020), and DHEA-S levels (β=9.98, 95% CI: 0.45 to 19.51, P=0.04) than controls. Protein-enriched soup with weekly exercise over 12weeks significantly improved physical performance, lipid profile, and DHEA-S levels among middle-aged and older adults with inadequate protein intake, while studies assessing long-term benefits of the intervention are needed.