Actively Recruiting
Effect of a Vegetarian Diet on the Bioavailability of Amino Acids From Plant Protein in Healthy Young and Elderly Volunteers (VEGAA)
Led by Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Updated on 2026-04-09
48
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are investigating how plant proteins, especially pea proteins, are digested and used in the body by young and older adults who follow vegetarian or omnivorous diets. The study focuses on understanding protein digestion and metabolism differences between these groups, which is important as plant proteins typically have lower digestibility than animal proteins. This research aims to provide insights into how aging might affect the availability of plant proteins, which is valuable for nutritional strategies targeting populations with higher protein needs, such as the elderly. Volunteers are divided into four groups based on age and diet: young vegetarians, young omnivores, older vegetarians, and older omnivores. Each participant attends two clinical investigation days separated by 4 weeks to 2 months. On the first day, they consume a pea-based meal labeled with a safe isotope (15N), and nitrogen retention and protein metabolism are measured through blood and urine samples over 8 hours. On the second day, participants eat portions of a pea-based meal labeled with another isotope (2H) every 30 minutes for 7.5 hours, combined with labeled amino acids (13C). Blood, breath, and respiratory samples are collected to evaluate amino acid digestibility and metabolism. Throughout the study, researchers collect blood samples, urine, breath, and measure respiratory exchanges to assess amino acid bioavailability, protein metabolism markers, and gut hormones. Participants' diets are characterized via an online questionnaire. The primary outcome is pea amino acid bioavailability measured over 8 hours on the second investigation day. Secondary outcomes include protein desamination and plasma kinetics of pea protein measured on the first day. The total participation spans two clinical visits separated by several weeks, ensuring detailed metabolic assessment under controlled conditions.
CONDITIONS
Brief Title
Effect of Vegetarien Diet on Protein Digestibility in Young and Elderly Volunteers
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Normal weight or overweight (BMI between 18 and 30 kg/m²)
- Male or female
- Age between 18-23 years (young groups) or 65-75 years (older groups)
- Following an omnivorous diet with meat intake more than 3 times per week and over 70% of protein from animal sources, or a vegetarian diet excluding meat and fish with over 70% of protein from plant sources
- In good general health (WHO = 0)
- Affiliated with a social security system
- Provided free and informed written consent after receiving required information
You will not qualify if you...
- Adults under legal protection or unable to give informed consent
- Known food allergies
- Positive serology for HBsAg, anti-HBc, HCV, or HIV
- Anemia with hemoglobin less than 13 g/dL in men or less than 12 g/dL in women
- Pregnant women or those who may be pregnant
- Excessive alcohol consumption (more than 2 drinks per day)
- Hypertension, diabetes, gastrointestinal, liver, kidney, or severe heart diseases
- High-level athletes training more than 8 hours per week
- Blood donation within 8 weeks prior to study
- Not affiliated with a social security system
- Lack of free, informed, written consent after receiving required information
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 1 day
Participants consume a pea-based meal labeled with 15N to measure dietary nitrogen kinetics through blood and urine samples collected over 8 hours.
1 clinical investigation day with blood samples taken regularly over 8 hours and urine collected every 2 hours
Duration - 1 day
Participants consume a pea-based meal labeled with 2H in portions every 30 minutes for 7.5 hours, along with doses of 13C-labeled amino acids, to determine amino acid digestibility and metabolic bioavailability using blood, breath, and respiratory measurements.
1 clinical investigation day with blood samples and breath samples collected regularly over 8 hours, and respiratory exchanges measured every hour
Trial Site Locations
Total: 1 location
1
Centre de Recherche sur Volontaire, Hopital Avicenne (AP-HP)
Bobigny, France
Actively Recruiting
Research Team
J
Juliane Calvez, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
SEQUENTIAL
Primary Purpose
BASIC_SCIENCE
Number of Arms
4
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