Dietary Protein Quality for Skeletal Muscle Anabolism in Older Adults

NCT05574205 | Completed

• 1 other identifier: RG_20-157
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Dietary proteins potently augment muscle protein synthesis. Because of poorer anabolic sensitivity with ageing, studies and guidelines recommend higher dietary protein intake for older adults. Although higher doses would benefit skeletal muscle remodelling, large protein consumption is not feasible for many older adults. To circumvent, high-protein quality which possesses a high amino acid profile and digestibility appears to have an emergent role for supporting anabolism. Since currently the best line of defence against age related muscle loss is resistance exercise training and regular protein consumption, emphasising high-quality protein ingestion, such as whey protein, within meals may be feasible and efficacious in supporting musculoskeletal remodelling in older adults, without requirement for large protein doses. The investigators propose that at low doses, high quality protein will have additive benefit to muscle protein synthesis compared to low-quality protein. Further, combining high-quality protein diets with resistance exercise training will have more profound benefits for muscle protein synthesis and muscle remodelling more so than low-quality protein diets.

Conditions

Sarcopenia; Dietary Protein; Resistance Exercise

Outcome Measures

Primary Outcomes (4)

• Muscle protein synthesis using muscle biopsies and deuterated water enrichment.

  Muscle protein synthesis will be assessed during the high-quality and low-quality intervention and compared between exercised and controlled leg.

  0-10 days

• Leg Strength using dynamometry

  Evaluating change in leg strength, of trained leg, pre- and post-intervention with high-quality and low-quality protein condition

  0-10 days

• Neural activation using interpolated twitch

  Assessing change in neural activation via non-invasive interpolated twitch technique of between exercised legs pre-and post intervention in both protein quality conditions

  0-10 days

• Muscle architecture using ultrasound

  Using non-invasive ultrasound to determine change of muscle structure with training between protein quality conditions.

  0-10 days

Secondary Outcomes (8)

• Appetite regulation using questionnaires

  0-10 days (3 hours postprandial)

• Appetite regulation, blood

  0-10 days (3 hours postprandial)

• Metabolic rate, metabolic cart

  0-10 days

• Nitrogen balance from urine and dietary protein intake

  0-10 days (24-hour urine collection)

• Body composition using Duel- energy x-ray absorptiometry (DXA) scan.

  0-10 days

Study Arms (2)

High Quality Protein

EXPERIMENTAL

Participants will consume four high-quality protein containing meals per day (amounting to 1g/kg/day of protein) over a 10-day period. Each meal will contain 75:25 animal:plant protein with most of the animal protein from supplemental high-quality protein powder.

Other: Resistance Exercise; Dietary Supplement: Protein supplementation

Low Quality Protein

EXPERIMENTAL

Participants will consume four low-quality protein containing meals per day (amounting to 1g/kg/day of protein) over a 10-day period. Each meal will contain 25:75 animal:plant protein with most of the plant protein from supplemental low-quality protein powder.

Other: Resistance Exercise; Dietary Supplement: Protein supplementation

Interventions

Resistance Exercise OTHER

Supervised single-leg (unilateral) exercise will be undertaken every other day throughout the dietary intervention

Also known as: Single-leg resistance exercise

High Quality Protein; Low Quality Protein

Protein supplementation DIETARY_SUPPLEMENT

Participants will consume a protein supplement alongside a provided diet to control protein amount and quality.

High Quality Protein; Low Quality Protein

Eligibility Criteria

• Age: 50 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Males and Females aged between 50-70 years
• Accustomed to normal physical activity levels (averaging at least 7000 steps a day)
• Healthy body mass (i.e., BMI 18-25 kg/m2)
• General good health indicated by health questionnaire
• Free from COVID-19 (SARS-CoV-2) symptoms.

You may not qualify if:

• Habitually high consumers of protein (\>1.6g/kg/day) assessed by habitual diet diary
• Food allergies
• Lidocaine allergy
• Smoker
• Bleeding Disorders
• Chronic/systemic illnesses (i.e., renal failure, rheumatoid arthritis, diabetes, poor lung function, heart disease, cancer, uncontrolled hypertension)
• Regular consumption of any analgesic or anti-inflammatory drugs. Taking medications mknown to affect muscle metabolis (e.g. beta-blockers, corticosteroids).

Sponsors & Collaborators

• University of Birmingham: lead
• Maastricht University: collaborator

Study Sites (1)

University of Birmingham, School of Sport, Exercise and Rehabilitation Sciences

Edgbaston, West Midlands, B15 2TT, United Kingdom

Location

Related Publications (1)

• Korzepa M, Quinlan JI, Marshall RN, Rogers LM, Belfield AE, Elhassan YS, Lawson A, Ayre C, Senden JM, Goessens JP, Glover EI, Wallis GA, van Loon LJ, Breen L. Resistance training increases myofibrillar protein synthesis in middle-to-older aged adults consuming a typical diet with no influence of protein source: a randomized controlled trial. Am J Clin Nutr. 2025 Jul;122(1):122-136. doi: 10.1016/j.ajcnut.2025.04.019. Epub 2025 Apr 25.

  PMID: 40288581 DERIVED

MeSH Terms

Conditions

Sarcopenia

Interventions

Resistance Training

Condition Hierarchy (Ancestors)

Muscular Atrophy; Neuromuscular Manifestations; Neurologic Manifestations; Nervous System Diseases; Atrophy; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: The participant will not know which condition they are under due to the contribution of animal and plant based elements within the diet, the conditions are not immediately obvious. Further, the higher and lower quality supplemental drinks have been made so the taste and texture of which are not discernible. The randomisation and counterbalancing will be done by a researcher separate to the project, using anonymised participant codes. The condition participants are under will be also completed before inducting participants. Researchers will be blinded to the condition and which leg was exercised during the analysis.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants will be randomly assigned to either the high-quality or low-quality condition. Within both conditions single-leg resistance exercise will be undertaken meaning the other non-exercise leg for each participant will act as their own internal control.

Study Record Dates

• First Submitted: September 29, 2022
• First Posted: October 10, 2022
• Study Start: November 1, 2021
• Primary Completion: December 1, 2023
• Study Completion: January 1, 2024
• Last Updated: August 1, 2024

Record last verified: 2021-09

Locations

GB (1)