Supplementation of a Leucine-enriched Protein Blend

June 18, 2024 updated by: Stuart Phillips, McMaster University

Supplementation of a Leucine-Enriched Dairy Protein Blend: Chronic and Acute Metabolic Responses in Young Men and Women

It is well known that dietary protein transiently stimulates muscle protein synthesis (MPS) whereby changes in MPS in response to feeding may be regulated by specific downstream target proteins of mammalian target of rapamycin signaling, such as S6K1, rpS6, and eIF2B. A meal deficient in protein, however, does not increase the rate of MPS because a rise in the bioavailability of amino acids does not occur. In addition, the source of dietary proteins has been shown to impact postprandial blood levels of amino acids. The concept that certain types of proteins are "fast acting" or "slow acting" has been shown to affect the postprandial profile of amino acids appearing in the systemic circulation. Native whey and micellar casein are both dairy proteins that contain a similar amount of essential (EAA), but blood EAA levels increase faster and to a higher level after the consumption of whey protein. Differences in gastric emptying, digestion and absorption kinetics between micellar casein and native whey are the underlying factors. Nonetheless, micellar casein protein has been shown to protract MPS in humans. Despite the significant amount of information gained with respect to both of these protein sources, the effects of combinatorial formulations on the postprandial profile of amino acids appearing in the blood is less well known.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

In a cross-over, randomized controlled trial, 10 healthy young participants (5 men and 5 women) will be recruited to undergo exercise resistance training randomized to habitual diet or habitual diet and supplementation (2 x per training session). For two of the training sessions the investigators will utilize a uni-lateral resistance exercise model to identify the acute effects of exercise and exercise + supplementation on the integrated rate of myofibrillar MPS within subject. This model enhances statistical power and eliminates between-subject differences impacting our outcomes. Throughout the study participants will record their macronutrient dietary intake. In addition, baseline body composition will be assessed with dual-energy x-ray absorptiometry.

Visit 1 (Day -7): Familiarization, strength testing and baseline body composition One week before the exercise trial, the investigators will ask participants to visit McMaster University to undergo a familiarization session with the exercise equipment and to perform 3-5 repetition maximum strength testing. This will allow the investigators to calculate the resistance (weight) participants will lift in their upcoming training sessions. The investigators will also perform a body composition scan using a dual-energy x-ray absorptiometry (DXA), assess participants' height and weight, and administer daily food logs with instructions to assess their habitual diet.

Visit 2 (Day 0): D2O administration and resting blood and saliva sampling One week after the familiarization visit, the investigators will ask participants to come to McMaster University in a fasted state and receive a dose of doubly labelled water D2O equal to 0.8mLs/kgBW and every hour for 3 hours after providing a blood and saliva sample. D2O is a safe, and widely used stable isotope, used to effectively measure the rate at which participants' muscle grow.

Visits 3 and 7 (Days 1 and 7): Resistance training program and muscle biopsy On these days participants will come to the lab in the morning following their habitual diet routine and will have a resting biopsy, blood and saliva samples taken. Next, participants may be asked to consume the supplement but will be asked to drink a small amount of D2O. Finally, participants will perform a combination resistance style exercise training session and immediately following training may be asked to consume the supplement.

Visit 4, 5, 8 & 9 (Days 2, 3, 8, 9): Resistance training program On these days participants will come to the lab in the morning following their habitual diet routine and have a saliva sample taken. Next, participants may be asked to consume the supplement but will be asked to drink a small amount of D2O. Finally, participants will perform a combination resistance style exercise training session and immediately following training participants may be asked to consume the supplement.

Visits 6 and 10 (Days 4 and 10): Uni-lateral acute training session and muscle biopsy On these days participants will come to the lab in the morning following their habitual diet routine. First, participants may be asked to consume the supplement immediately before performing a uni-lateral acute resistance training session. Participants will be asked to drink a small amount of D2O but only during Visit 6 (Day 4). Immediately following training, participants may be asked to consume the supplement. One hour following exercise participants will have a muscle biopsy, blood and saliva samples taken.

Days 5 and 6 (see attached study timeline): Washout period The investigators will ask that participants drink one aliquot of D2O on day 5 and one aliquot of D2O on day 6. One hour after participants drink the aliquot of D2O the investigators ask that participants take their own saliva sample at home (D2O aliquots and a sampling kit will be provided with instructions).

Study Type

Interventional

Enrollment (Actual)

8

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8S 4K1
        • Exercise Metabolism Research Laboratory, McMaster Univeristy

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 29 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Be between the ages of 18-29 years (inclusive)
  • Be able to maintain a habitual diet, physical activity patterns, and body mass throughout the trial
  • Be in general good health
  • Be able to participate in resistance training and aerobic training
  • Understand the study procedures and sign this form providing informed consent to participate in the study
  • Be able to consume a protein bar in the allotted time frame of 10 minutes

Exclusion Criteria:

  • Smoker
  • Excessive alcohol consumption (more than 21 units of alcohol / week; 1 unit of alcohol is approximately 25 mL of spirits (40% alcohol), 250 mL of beer (4% alcohol) or 75 mL of wine (13% alcohol))
  • Have health problems such as: renal or gastrointestinal disorders, metabolic disease, heart disease, vascular disease, rheumatoid arthritis, diabetes, poor lung function, uncontrolled blood pressure, dizziness, thyroid problems, or any other health conditions for which you are being treated that might put you at risk for this study
  • Have a known or suspected allergy to local anesthetics such as lidocaine
  • Have a dairy protein allergy
  • Participation in another nutrition or exercise research study
  • Do not understand English or have a condition the PI believes would interfere with a participants' ability to provide informed consent, comply with the study protocol, or which might confound the interpretation of the study results or put someone at undue risk
  • Use of medications known to affect protein metabolism (i.e. corticosteroids, or prescription strength acne medications)
  • Consuming a vegan diet
  • Use of an investigational drug product or nutraceutical within the last 30 days
  • Any concurrent medical, orthopedic, or psychiatric condition that, in the opinion of the Investigators, would compromise the ability to comply with the study requirements

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Leucine-enriched protein + exercise
whey protein- hydrolyzed whey protein-micellar casein blend (50:43:7 whey:hydrolyzed-whey:casein), vitamin D, and free leucine
Dietary supplement: Leucine-enriched protein
Supplement contains 16g of protein given twice per exercise session (4 total exercise sessions)
Sham Comparator: Habitual diet + exercise
habitual diet only
Behavioral: Habitual diet only
Habitual diet only (no supplementation) for 4 exercise sessions

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Integrated Muscle Protein Synthetic Rate
Time Frame: 10 days
oral deuterium consumption: Isotope protocol (See ref., PMID 23821570)
10 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

McMaster University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2019

Primary Completion (Actual)

March 1, 2020

Study Completion (Actual)

March 1, 2020

Study Registration Dates

First Submitted

January 7, 2019

First Submitted That Met QC Criteria

January 7, 2019

First Posted (Actual)

January 8, 2019

Study Record Updates

Last Update Posted (Actual)

June 20, 2024

Last Update Submitted That Met QC Criteria

June 18, 2024

Last Verified

June 1, 2024

More Information

Terms related to this study

Other Study ID Numbers

  • 5706

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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