Plant Protein Blend and Milk Protein Supplements in Older Individuals (Blend-D2O)

The Effectiveness of Daily Protein Supplementation With a Plant Protein Blend or Milk Protein to Support Integrated Muscle Protein Synthesis Rates With and Without Exercise in Healthy Older Individuals

Background Protein intake is important for skeletal muscle mass maintenance with aging and the ingestion of specifically-timed protein supplements could increase overall protein intake and thereby contribute to skeletal muscle mass maintenance. Recently, more attention has been given to the ingestion of plant-based protein blends as a more sustainable high-quality alternative to milk protein, as a means to increase muscle protein build-up and, as such, support muscle maintenance, especially when consuming suboptimal amounts of protein in the regular diet.

Objective To assess the benefit of daily protein supplementation with either a plant-based protein blend or a milk protein on top of a standard diet to stimulate integrated muscle protein synthesis rates in healthy older individuals with and without exercise.

Hypotheses It is hypothesized that both the plant protein blend and the milk protein supplement will result in greater muscle protein build-up when compared with a standard diet control condition.

It is also hypothesized that exercise will result in greater muscle protein build-up when compared to the resting leg in all conditions, with similar effects of the protein supplements vs the control diet as in the non-exercised leg.

This study will show the potential benefit of protein supplementation with alternative protein sources to support skeletal muscle maintenance in older individuals.

Study Overview

• Status: Completed
• Conditions: Sarcopenia; Skeletal Muscle Atrophy; Protein Malnutrition
• Intervention / Treatment: Behavioral: Resistance exercise; Behavioral: Standardized diet; Dietary supplement: Maltodextrin supplement; Dietary supplement: Milk protein supplement; Dietary supplement: Plant protein supplement

• Study Type: Interventional
• Enrollment (Actual): 51
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Maastricht, Limburg, Netherlands, 6229ER
      • Maastricht University Medical Center+

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male or female sex
• Aged between 60 and 80 y inclusive
• BMI between 18.5 and 30 kg/m2

Exclusion Criteria:

• Following a self-reported vegetarian and vegan diet the 6 months prior to the study.
• Intolerant to milk products
• Corn allergy
• Pea allergy
• Participating currently or in the 3 months prior to the study in a structured (progressive) exercise program.
• Smoking regularly (i.e. >5 cigarettes/week)
• History of cardiovascular, respiratory, gastrointestinal, urogenital, neurological, psychiatric, dermatologic, musculoskeletal, metabolic, endocrine, haematological, immunologic disorders, allergy, major surgery and/or laboratory assessments which might limit participation in or completion of the study protocol, interfere with the execution of the experiment, or potential influence the study outcomes (to be decided by the principal investigator and responsible physician)
• Diagnosed with phenylketonuria (PKU)
• Uncontrolled hypertension (blood pressure above 160/100 mmHg)
• Donated blood 3 months prior to test day
• Use of any medications that interferes with study participation and/or outcomes (i.e. corticosteroids, non-steroidal anti-inflammatories, gastric acid suppressing medication) as assessed by the responsible medical doctor.
• Use of DOAC, vitamin-K-antagonist, or multiple anticoagulants
• Pregnancy

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Maltodextrin; daily 2 x 20g maltodextrin ingestion	Behavioral: Resistance exercise; 4 single-leg exercise sessions; Other Names: Resistance training; Strength exercise; Behavioral: Standardized diet; Fully standardized provided energy-balanced diet providing recommended daily allowance for protein.; Dietary supplement: Maltodextrin supplement; Dissolved in water with breakfast and prior to sleep.
Experimental: Milk protein; daily 2 x 20g milk protein ingestion	Behavioral: Resistance exercise; 4 single-leg exercise sessions; Other Names: Resistance training; Strength exercise; Behavioral: Standardized diet; Fully standardized provided energy-balanced diet providing recommended daily allowance for protein.; Dietary supplement: Milk protein supplement; Dissolved in water with breakfast and prior to sleep.
Experimental: Plant protein blend; daily 2 x 20g plant protein blend ingestion	Behavioral: Resistance exercise; 4 single-leg exercise sessions; Other Names: Resistance training; Strength exercise; Behavioral: Standardized diet; Fully standardized provided energy-balanced diet providing recommended daily allowance for protein.; Dietary supplement: Plant protein supplement; Dissolved in water with breakfast and prior to sleep.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Integrated muscle protein synthesis rates in the non-exercised leg.	Calculated by the changein deuterium labelled alanine in skeletal muscle protein	10 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dietary protein intake	Assessed by calculating the actual intakes from the provided diet	10 days
Dietary fat intake	Assessed by calculating the actual intakes from the provided diet	10 days
Dietary carbohydrate intake	Assessed by calculating the actual intakes from the provided diet	10 days
Step count	Assessed using a accelerometer	10 days
Muscle Crosssectional are	Assessed using Ultrasound	10 days
Integrated muscle protein synthesis rates in the exercised leg.	Calculated by the change in deuterium labelled alanine in skeletal muscle protein	10 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Age (year)	Interview question	At baseline
Body mass (kg)	Assessed using scale	At baseline
Height (m)	Assessed using stadiometer	At baseline
Body fat %	Assessed using Dexa scan	At baseline
Lean body mass (kg)	Assessed using Dexa scan	At baseline
Appendicular lean mass (kg)	Assessed using Dexa scan	At baseline
Sex	Biological sex checked using interview	At baseline
Systolic and diastolic blood pressure	Automated measurement	At baseline

Collaborators and Investigators

• Sponsor: Maastricht University Medical Center
• Collaborators: Cargill
• Investigators: Principal Investigator: Luc van Loon, PhD, Maastricht University

Study record dates

Study Major Dates

• Study Start (Actual): June 26, 2024
• Primary Completion (Actual): December 5, 2025
• Study Completion (Actual): December 5, 2025

Study Registration Dates

• First Submitted: May 3, 2024
• First Submitted That Met QC Criteria: May 6, 2024
• First Posted (Actual): May 7, 2024

Study Record Updates

• Last Update Posted (Actual): December 18, 2025
• Last Update Submitted That Met QC Criteria: December 10, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Muscle protein synthesis
• Additional Relevant MeSH Terms: Severe Acute Malnutrition; Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Nutrition Disorders; Pathological Conditions, Anatomical; Atrophy; Malnutrition; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Sarcopenia; Muscular Atrophy; Kwashiorkor; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Physical Conditioning, Human; Exercise; Resistance Training
• Other Study ID Numbers: NL85365.068.23 / METC23-050

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