Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial

Abstract

Background Aging appears to attenuate the response of skeletal muscle protein synthesis (MPS) to anabolic stimuli such as protein ingestion (and the ensuing hyperaminoacidemia) and resistance exercise (RE). Objectives The purpose of this study was to determine the effects of protein quality on feeding- and feeding plus RE–induced increases of acute and longer-term MPS after ingestion of whey protein (WP) and collagen protein (CP). Methods In a double-blind parallel-group design, 22 healthy older women (mean ± SD age: 69 ± 3 y, n = 11/group) were randomly assigned to consume a 30-g supplement of either WP or CP twice daily for 6 d. Participants performed unilateral RE twice during the 6-d period to determine the acute (via [13C6]-phenylalanine infusion) and longer-term (ingestion of deuterated water) MPS responses, the primary outcome measures. Results Acutely, WP increased MPS by a mean ± SD 0.017 ± 0.008%/h in the feeding-only leg (Rest) and 0.032 ± 0.012%/h in the feeding plus exercise leg (Exercise) (both P < 0.01), whereas CP increased MPS only in Exercise (0.012 ± 0.013%/h) (P < 0.01) and MPS was greater in WP than CP in both the Rest and Exercise legs (P = 0.02). Longer-term MPS increased by 0.063 ± 0.059%/d in Rest and 0.173 ± 0.104%/d in Exercise (P < 0.0001) with WP; however, MPS was not significantly elevated above baseline in Rest (0.011 ± 0.042%/d) or Exercise (0.020 ± 0.034%/d) with CP. Longer-term MPS was greater in WP than in CP in both Rest and Exercise (P < 0.001). Conclusions Supplementation with WP elicited greater increases in both acute and longer-term MPS than CP supplementation, which is suggestive that WP is a more effective supplement to support skeletal muscle retention in older women than CP. This trial was registered at clinicaltrials.gov as NCT03281434.

Potato Protein Isolate Stimulates Muscle Protein Synthesis at Rest and with Resistance Exercise in Young Women

“…Performance of RE serves to sensitize skeletal muscle to the anabolic effects of protein ingestion, such that rates of MPS are further enhanced when protein is consumed in temporal proximity to performance of RE [8,29]. Our finding that high repetition RE and supplementation with PP increased rates of MPS above the consumption of PP isolate alone is in line with previous acute measurements from our laboratory in healthy young men [8,29] as well as previous investigations measuring integrated rates of MPS in healthy older women [9,30,31]. Burd et al reported that both higher repetition (lower weight) and lower repetition (higher weight) RE when performed to volitional fatigue and combined with protein ingestion, facilitated elevations in MPS and the Akt/mTOR pathway for 24 h [29].…”

“…The MPS response to amino acid feeding can vary markedly depending on the quality of the protein source. Specifically, complete proteins (a protein containing all of the essential amino acids [EAA]), and protein sources higher in leucine, augment rates of MPS to a greater extent than incomplete proteins and those lower in leucine [6][7][8][9][10]. Leucine is able to independently stimulate MPS through its interaction with mTORC1 [11], and thus, is critical for the determination of feeding-induced rates of MPS.…”

Animal, Plant, Collagen and Blended Dietary Proteins: Effects on Musculoskeletal Outcomes

“…Moreover, in the western population, there is an apparent shift towards increased consumption of plant-derived protein (in lieu of animal), due to perceived health benefits (e.g., reduced cardiovascular mortality [22]) and environmental sustainability [6]. Reflecting this shift, while the majority of prior research investigations have focused upon characterising the effects of animal-derived proteins in relation to musculoskeletal metabolism and health, there has been a recent surge of studies investigating the influence of plant-derived (e.g., References [4,[23][24][25]), collagen-derived (e.g., References [26][27][28][29]) and blended (e.g., References [30][31][32]) protein sources.…”

“…As such, collagen supplementation, in the form of collagen hydrolysates or gelatin, has recently gained popularity as an alternative or adjunct protein source to animal-and/or plant-derived sources for maintaining or even potentiating muscle and/or bone health (i.e., mass/function). This may seem counterintuitive since dietary collagen is rich in non-essential amino acids (NEAA's; e.g., proline, glycine), low in EAA's (e.g., methionine, leucine) and lacks tryptophan, rendering a DIAAS of 0 [27]. Expectedly, this has led to some questioning the anabolic potential of dietary collagen, at least compared to high-quality protein sources such as whey protein, which contain high levels of leucine and have a DIAAS of >1 [123].…”

“…Other data shows blunted RE-induced increases in anabolic signalling (p70S6K) (collagen vs. whey protein) [129] and muscle sub-fraction (myofibrillar and sarcoplasmic) MPS (collagen vs. α-lactalbumin) [130], with collagen protein, albeit in the context of short-term (3-days) aerobic exercise. The lack of tryptophan and low methionine and leucine content [27] in dietary collagen may explain the non-hypertrophic responses when used in an unblended fashion (i.e., when not blended with other dietary protein sources). Instead, it has been suggested that increased connective tissue/extracellular matrix (ECM) remodelling may contribute to the favourable changes in fat-free mass that are observed [128].…”