Whey protein but not collagen peptides stimulate acute and ...

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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.

Keywords:

muscle protein synthesis

whey protein

collagen peptides

protein quality

resistance exercise

older women

Abbreviations used:

AA

amino acid

AKT

protein kinase B

Cmax

concentration max

CP

collagen peptide

CPS

collagen protein synthesis

EAA

essential amino acid

Exercise

feeding plus exercise leg

LBM

lean body mass

MCPS

muscle collagen protein synthesis

MPS

muscle protein synthesis

mTOR

mechanistic target of rapamycin

MyoPS

myofibrillar muscle protein synthesis

RE

resistance exercise

Rest

feeding leg

S6

ribosomal protein S6

Tmax

time to concentration maximum

WP

whey protein

1RM

1-repetition maximum.

Supported by Canadian Institutes of Health Research grant 399384 (to SMP).

Data described in the article will be made available upon request pending filing of any IP and patent claims.

Copyright © 2020 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.