Resistance training increases myofibrillar protein synthesis in middle-to-older aged adults consuming a typical diet with no influence of protein source: a randomized controlled trial.
Study Goal
The researchers aimed to determine the impact of protein source (animal vs. plant) and resistance exercise training (RET) on muscle anabolism and metabolic health in middle-to-older aged adults.
Results Summary
RET significantly increased daily integrated myofibrillar protein synthesis (iMyoPS) rates in both legs, regardless of protein source. The study found no differences in muscle architecture, strength, metabolic rate, or renal function between protein sources, but plant protein reduced non-HDL cholesterol.
Population
Middle-to-older aged adults (50-70 years old).
Effective Dosage
1.0g·kg BM-1·day-1 of protein from either animal (whey) or plant (pea) sources.
Duration
10 days.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
animal-focused whey protein-supplemented diet (AW-D) | increase | daily integrated myofibrillar protein synthesis (iMyoPS) rates | middle-to-older aged adults | 1.44 ± 0.26 vs 1.29 ± 0.27 %⋅day-1 | significantly greater | #1 |
plant-focused pea protein-supplemented diet (PP-D) | increase | daily integrated myofibrillar protein synthesis (iMyoPS) rates | middle-to-older aged adults | 1.50 ± 0.17 vs 1.34 ± 0.21 %⋅day-1 | significantly greater | #2 |
animal-focused whey protein-supplemented diet (AW-D) | no change | intracellular anabolic signalling, muscle architecture, strength, metabolic rate, renal function or whole-body nitrogen balance (WBNB) | middle-to-older aged adults | - | did not affect | #3 |
plant-focused pea protein-supplemented diet (PP-D) | no change | intracellular anabolic signalling, muscle architecture, strength, metabolic rate, renal function or whole-body nitrogen balance (WBNB) | middle-to-older aged adults | - | did not affect | #4 |
plant-focused pea protein-supplemented diet (PP-D) | decrease | serum non-HDL cholesterol | middle-to-older aged adults | pre: 3.89 ± 0.84, post 3.37 ± 0.78 mmol⋅L | significantly lower | #5 |
animal-focused whey protein-supplemented diet (AW-D) | no change | lipid profiles | middle-to-older aged adults | - | no other changes | #6 |
plant-focused pea protein-supplemented diet (PP-D) | no change | lipid profiles | middle-to-older aged adults | - | no other changes | #7 |
10-day provision of 1.0g·kg BM-1·day-1 from predominantly plant-derived or animal-derived protein | no change | daily iMyoPS rates | middle-to-older aged adults | - | does not influence | #8 |
10-day provision of 1.0g·kg BM-1·day-1 from predominantly plant-derived or animal-derived protein | no change | metabolic and renal health parameters | middle-to-older aged adults | - | has little impact on | #9 |
resistance exercise training (RET) | increase | rates of daily iMyoPS | middle-to-older aged adults consuming a typical protein-containing diet | - | enhances | #10 |
resistance exercise training (RET) | no change | protein source | middle-to-older aged adults consuming a typical protein-containing diet | - | no influence of | #11 |
BACKGROUND: The primary protein source of a diet may impact skeletal muscle maintenance with advancing age. The impact of the animal and plant protein content of a typical protein-containing diet on muscle anabolism in middle-to-older aged adults is unknown. OBJECTIVES: To determine muscle adaptive remodelling response to a 10-day dietary intervention containing divergent protein sources, with and without resistance exercise training (RET) in middle-to-older aged adults. METHODS: In a single-blind randomized control trial, twenty-seven 50-70-year-old participants consumed 1.0g·kg BM-1·day-1 of protein from an animal-focused whey protein-supplemented diet (AW-D) or plant-focused pea protein-supplemented diet (PP-D). Throughout the 10-day diet intervention, unilateral knee extensor RET was performed every other day. Deuterated water ingestion and skeletal muscle biopsies enabled measurement of daily integrated myofibrillar protein synthesis (iMyoPS) rates in the trained, and untrained legs. Changes in metabolic rate, body composition, lipid profiles, renal function, whole-body nitrogen balance (WBNB), strength and muscle architecture were also determined. RESULTS: Daily iMyoPS rates were significantly greater (P<0.001) in the trained compared to the untrained leg for AW-D (1.44 ± 0.26 vs 1.29 ± 0.27 %⋅day-1) and PP-D (1.50 ± 0.17 vs 1.34 ± 0.21 %⋅day-1) with no differences between groups, within leg. Training and diet did not affect intracellular anabolic signalling, muscle architecture, strength, metabolic rate, renal function or WBNB. Serum non-HDL cholesterol was significantly (P=0.014) lower following the intervention for PP-D only (pre: 3.89 ± 0.84, post 3.37 ± 0.78 mmol⋅L) with no other changes in lipid profiles. CONCLUSIONS: The 10-day provision of 1.0g·kg BM-1·day-1 from predominantly plant-derived or animal-derived protein does not influence daily iMyoPS rates in middle-to-older aged adults and has little impact on metabolic and renal health parameters. RET enhances rates of daily iMyoPS in middle-to-older aged adults consuming a typical protein-containing diet, with no influence of protein source. CLINICAL TRIAL REGISTRY NUMBER: ClinicalTrials.gov NCT05574205 https://clinicaltrials.gov/study/NCT05574205.