Effects of Soy Milk in Conjunction With Resistance Training on Physical Performance and Skeletal Muscle Regulatory Markers in Older Men

Abstract

Purpose: We aimed to determine the effects of 12 weeks of soy milk consumption combined with resistance training (RT) on body composition, physical performance, and skeletal muscle regulatory markers in older men. Methods: In this randomized clinical trial study, 60 healthy elderly men (age = 65.63 ± 3.16 years) were randomly assigned to four groups: resistance training (RT; n = 15), soy milk consumption (SMC; n = 15), resistance training + soy milk (RSM; n = 15), and control (CON; n = 15) groups. The study was double-blind for the soy milk/placebo. Participants in RT and RSM groups performed resistance training (3 times/week) for 12 weeks. Participants in the SMC and RSM groups consumed 240 mL of soy milk daily. Body composition [body mass (BM), body fat percent (BFP), waist-hip ratio (WHR), and fat mass (FM)], physical performance [upper body strength (UBS), lower body strength (LBS), VO2max, upper anaerobic power, lower anaerobic power, and handgrip strength], and serum markers [follistatin, myostatin, myostatin-follistatin ratio (MFR), and growth and differentiation factor 11 (GDF11)] were evaluated before and after interventions. Results: All 3 interventions significantly (p < 0.05) increased serum follistatin concentrations (RT = 1.7%, SMC = 2.9%, RSM = 7.8%) and decreased serum myostatin (RT = −1.3% SMC = −5.4%, RSM = −0.5%) and GDF11 concentrations (RT = −1.4%, SMC = −1.4%, RSM = -9.0%), and MFR (RT = −2.6%, SMC = −3.2%, RSM = −12%). In addition, we observed significant reduction in all 3 intervention groups in BFP (RT = −3.6%, SMC = −1.4%, RSM = −6.0%), WHR (RT = −2.2%, SMC = −2.1%, RSM = −4.3%), and FM (RT = −9.6%, SMC = −3.8%, RSM = −11.0%). Moreover, results found significant increase only in RT and RSM groups for muscle mass (RT = 3.8% and RSM = 11.8%), UBS (RT = 10.9% and RSM = 21.8%), LBS (RT = 4.3% and RSM = 7.8%), upper anaerobic power (RT = 7.8% and RSM = 10.3%), and lower anaerobic power (RT = 4.6% and RSM = 8.9%). Handgrip strength were significantly increased in all 3 intervention groups (RT = 7.0%, SMC = 6.9%, RSM = 43.0%). VO2max significantly increased only in RSM (1.7%) after 12 weeks of intervention. Additionally, significant differences were observed between the changes for all variables in the RSM group compared to RT, SMC, and CON groups (p < 0.05). Conclusions: There were synergistic effects of soy milk and RT for skeletal muscle regulatory markers, body composition, and physical performance. Results of the present study support the importance of soy milk in conjunction with RT for older men.

Serum myostatin as a candidate disease severity and progression biomarker of spinal muscular atrophy

“…The increase in the follistatin:myostatin ratio appears to be a consequence of the reduction in myostatin levels in SMA and is associated with positive regulators of muscle growth in healthy individuals, promoting muscle hypertrophy. 48 While not directly demonstrated, it can be inferred that the study involving four cases of SMA also showed an increase in the follistatin:myostatin ratio, considering the slightly elevated levels of follistatin and the reduced levels of myostatin observed. 40 These findings differ from a study conducted in amyotrophic lateral sclerosis, where a decrease in the follistatin:myostatin ratio was observed in patients compared to controls.…”

Effects of Plant-Based Protein Interventions, with and without an Exercise Component, on Body Composition, Strength and Physical Function in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…The included study characteristics are reported in Table 3 . The studies were conducted in United States ( n = 3, [ 47 , 48 , 49 ]), Japan ( n = 3, [ 50 , 51 , 52 ]), Iran ( n = 2, [ 53 , 54 ]), Netherlands ( n = 1, [ 46 ]), China ( n = 1, [ 55 ]), and Brazil ( n = 1, [ 56 ]). In total, there were 806 participants included from studies published between 2002–2022.…”

“…The overall daily dose of protein varied from 0.6 g to 60 g. Most studies provided protein supplementation daily, except for Imaoka et al [ 50 , 51 ] which provided one 4.4 g dose of soy peptide drink once per week. Six studies included an exercise component of either resistance training (RT), aerobic training or both [ 47 , 50 , 51 , 52 , 54 , 56 ]. Bijeh et al [ 54 ] was the only study to include a soy only arm, and a soy + RT arm, which could be compared separately to a control (no intervention) and RT only arm, respectively.…”

“…Six studies included an exercise component of either resistance training (RT), aerobic training or both [ 47 , 50 , 51 , 52 , 54 , 56 ]. Bijeh et al [ 54 ] was the only study to include a soy only arm, and a soy + RT arm, which could be compared separately to a control (no intervention) and RT only arm, respectively. Comparisons included animal protein [ 46 , 47 , 48 , 49 , 52 , 54 , 55 , 56 ], no intervention control [ 53 , 55 ], and exercise only controls [ 50 , 51 , 54 , 56 ].…”

The value of dietary plant protein in older people

“…For example, soy proteins are generally considered a high-quality source of dietary proteins with favourable EAAs content. Several authors showed that consumption of isolated soy protein or soy milk combined with resistance exercise improve muscle strength and mass in older persons [17][18][19]. Finally, enriching plant-based protein sources with dairy proteins is another nutritional strategy that could be used to enhance nutritional benefits.…”