Journal Article

Native whey protein with high levels of leucine results in similar post-exercise muscular anabolic responses as regular whey protein: a randomized controlled trial

Nordengen, Anne Lene, Holte, Kristin, Paulsen, Gøran, Cotter, Matthew, Hamarsland, Håvard, Benestad, Haakon B., Børsheim, Elisabet, Nyvik Aas, Sigve, Raastad, Truls, Garthe, Ina

2017

Overview

Background Protein intake is essential to maximally stimulate muscle protein synthesis, and the amino acid leucine seems to possess a superior effect on muscle protein synthesis compared to other amino acids. Native whey has higher leucine content and thus a potentially greater anabolic effect on muscle than regular whey (WPC-80). This study compared the acute anabolic effects of ingesting 2 × 20 g of native whey protein, WPC-80 or milk protein after a resistance exercise session. Methods A total of 24 young resistance trained men and women took part in this double blind, randomized, partial crossover, controlled study. Participants received either WPC-80 and native whey ( n  = 10), in a crossover design, or milk ( n  = 12). Supplements were ingested immediately (20 g) and two hours after (20 g) a bout of heavy-load lower body resistance exercise. Blood samples and muscle biopsies were collected to measure plasma concentrations of amino acids by gas-chromatography mass spectrometry, muscle phosphorylation of p70S6K, 4E–BP1 and eEF-2 by immunoblotting, and mixed muscle protein synthesis by use of [ 2 H 5 ]phenylalanine-infusion, gas-chromatography mass spectrometry and isotope-ratio mass spectrometry. Being the main comparison, differences between native whey and WPC-80 were analysed by a one-way ANOVA and comparisons between the whey supplements and milk were analysed by a two-way ANOVA. Results Native whey increased blood leucine concentrations more than WPC-80 and milk ( P  < 0.05). Native whey ingestion induced a greater phosphorylation of p70S6K than milk 180 min after exercise ( P  = 0.03). Muscle protein synthesis rates increased 1–3 h hours after exercise with WPC-80 (0.119%), and 1–5 h after exercise with native whey (0.112%). Muscle protein synthesis rates were higher 1–5 h after exercise with native whey than with milk (0.112% vs. 0.064, P  = 0.023). Conclusions Despite higher-magnitude increases in blood leucine concentrations with native whey, it was not superior to WPC-80 concerning effect on muscle protein synthesis and phosphorylation of p70S6K during a 5-h post-exercise period. Native whey increased phosphorylation of p70S6K and muscle protein synthesis rates to a greater extent than milk during the 5-h post exercise period. Trial registration This study was retrospectively registered at clinicaltrials.gov as NCT02968888 .

• Publisher: BioMed Central,BioMed Central Ltd,Taylor & Francis Ltd,Taylor & Francis Group
• Subject: Amino acids / Analysis / analysis of variance / biopsy / blood / blood sampling / Chromatography / Clinical Nutrition / Cross-Over Studies / Diet / Dietary Supplements / Double-Blind Method / Female / gas chromatography / Healthy Volunteers / Humans / immunoblotting / leucine / Leucine - analysis / Leucine - pharmacology / Male / Mass spectrometry / Medical research / Medical screening / Medicine / Medicine & Public Health / men / Milk / Milk proteins / muscle protein / Muscle Proteins - biosynthesis / Muscle, Skeletal - drug effects / Muscle, Skeletal - physiology / muscles / nutrition / Nutrition research / Phenylalanine / phosphorylation / Physical fitness / Protein Biosynthesis - drug effects / protein intake / protein quality / Protein synthesis / Proteins / randomized clinical trials / Research Article / Resistance Training / Skeletal muscle / Sports Medicine / sports nutrition / Sports Nutritional Physiological Phenomena / stable isotopes / strength training / supplementation / whey / whey protein / Whey Proteins - chemistry / Whey Proteins - pharmacology / women / Young Adult