The Effect of a Plant Protein Isolate on Muscle Protein Synthesis in Humans at Rest and After Resistance Exercise

The Effect of a Plant Protein Isolate on Muscle Protein Synthesis in Humans at Rest, and After Resistance Exercise: A Randomized Controlled Trial

Plant-based proteins contain several amino acids that are essential to signal growth, reconditioning, maintenance and preservation of skeletal muscle mass. This study aims to inform on the nutrient activation of muscle protein synthesis (MPS) by feeding a plant protein isolate equivalent to 0.33 g of protein per kilogram of body mass.

Study Overview

• Status: Completed
• Conditions: Exercise; Dietary Supplements; Metabolism
• Intervention / Treatment: Dietary supplement: NEAA; Dietary supplement: PPI

Detailed Description

Participants: 32 young, healthy men and women aged 18 - 35 years. Intervention: Plant protein isolate (PPI) and nonessential amino acid control (NEAA) Study Design: Block randomised control trial. Two group parallel design. Primary outcome: Myofibrillar fractional synthetic rate (myoFSR).

Preliminary screening/familiarization consists of: medical history, dietary assessment and examination by a medical doctor and a qualified dietician, blood sample to be evaluated for health-related contraindications, body composition measurement by dual energy x-ray absorptiometry (DXA), isokinetic knee extensor strength tests.

Pre-trial: A metered dose of deuterium oxide (5ml/kg) will be ingested and blood and/or saliva (~5ml) samples will be collected pre/post ingestion.

Experimental trial: Blood, saliva and bilateral m.vastus lateralis microbiopsies (~100 mg) collected. A unilateral resistance-training session consisting of knee extensor contractions will be completed. Following exercise cessation participants will ingest 0.33 g/kg body mass of either: a nonessential amino acid formulation or a plant-protein isolate. A saliva sample and a 2nd set of bilateral m.vastus lateralis microbiopsies are collected 3 h postingestion.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Ireland
  • Munster
    • Limerick, Munster, Ireland, V94 T9PX
      • University of Limerick

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

- Men and women aged 18 to 35 years

Exclusion Criteria:

• Known intolerance to any item contained in the protein products.
• Blood borne disease risk, current illness or medication that would adversely affect participation
• Known adverse reaction to venepuncture and/or biopsy
• Inability to undertake resistance exercise
• Inability to adhere to protocol guidelines

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Nonessential amino acid formulation (NEAA); Novel non-essential amino acid blend dosed at 0.33 g/kg body mass in 400 ml of water. Postprandial muscle protein synthesis at rest, and after resistance exercise to be measured by deuterium incorporation in to skeletal muscle sampled by bilateral microbiopsies. Product Number: NEAA56812	Dietary supplement: NEAA; Food grade mixture of non-essential amino acids in powdered form to be dissolved in water. Supplied by Marigot Ltd, Cork, Ireland
Active Comparator: Plant Protein Isolate (PPI); Plant protein isolate (Fava bean) dosed at 0.33 g/kg body mass in 400 ml of water. Postprandial muscle protein synthesis at rest, and after resistance exercise to be measured by deuterium incorporation in to skeletal muscle sampled by bilateral microbiopsies. Product Number: FP2011273	Dietary supplement: PPI; Food grade plant (legume - Fava) protein isolate to be dissolved in water. Supplied by Marigot Ltd, Cork, Ireland; Other Names: Plant Protein Isolate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Myofibrillar fractional synthetic rate change	The fractional rate of myofibrillar protein synthesis measured by deuterium incorporation into skeletal muscle sampled by microbiopsy	4 hours

Collaborators and Investigators

• Sponsor: University of Limerick
• Collaborators: Marigot Ltd.; Enterprise Ireland
• Investigators: Principal Investigator: Robert W Davies, PhD, University of Limerick

Study record dates

Study Major Dates

• Study Start (Actual): September 14, 2021
• Primary Completion (Actual): June 20, 2022
• Study Completion (Actual): June 20, 2022

Study Registration Dates

• First Submitted: August 17, 2021
• First Submitted That Met QC Criteria: August 24, 2021
• First Posted (Actual): August 25, 2021

Study Record Updates

• Last Update Posted (Actual): June 22, 2022
• Last Update Submitted That Met QC Criteria: June 20, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Keywords: humans; protein synthesis; skeletal muscle; resistance training; amino acids; deuterium oxide; plant proteins
• Other Study ID Numbers: 2020_04_07_EHS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No