MA of Tryptophan in Cornmeal in Healthy Adults>60y

NCT07272668 | Enrolling By Invitation

• 1 other identifier: 3568
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

The world's population will reach 12 billion by this century's end. As the human population increases, the world faces the continuous challenge of optimizing a limited food supply. Protein is the key determinant of growth and bodily function. Recently, our group showed that current protein recommendations for adults and children are underestimated by 30-50%. Animal protein production is "more resource intensive than any other form of food production" and their high saturated fat content is linked to chronic diseases in developed nations. Plant protein sources are important alternatives shown to "enhance ecosystem resilience and improve human health". Maize, commonly known as corn, is a staple food in the diets of more than 300 million Africans and ranks as the third most produced food globally. Maize supplies up to 80% of daily energy in sub-Saharan and Southern Africa alone. It is one of the main protein sources in these countries for vegetarians. Already, over 900,000 Canadians adults are vegetarians and globally plant protein consumption is encouraged. However, maize protein is limiting in the essential amino acid (EAA) tryptophan and anti-nutritional factors can affect tryptophan bioavailability (BA). Dietary protein quality (DPQ) depends on its amino acid (AA) composition and BA. Therefore, knowledge of tryptophan BA is fundamental to understand the extent to which cereal grains meet the body's requirement for protein synthesis (PS). Efforts aimed at increasing crop production and DPQ, should coincide with DPQ evaluation directly in humans so that the gap in knowledge between protein requirement and how best to provide it can be quickly and efficiently reconciled.

Conditions

Protein Absorption and Amino Acid Availability

Keywords

elderly; healthy; tryptophan; amino acid availability; metabolic availability; indicator amino acid oxidation; iaao; stable isotopes

Outcome Measures

Primary Outcomes (1)

• MA of tryptophan in maize

  To measure the tryptophan metabolic availability investigators will collect breath samples from participants. From these samples, investigators will measure the amount of amino acids oxidized and how much is retained in the body when graded intakes of tryptophan are consumed by the participants consuming a controlled diet.

  Up to 24 months

Study Arms (1)

MA of tryptophan in maize

EXPERIMENTAL

Apply the IAAO method to determine the metabolic availability of tryptophan in maize prepared by moist cooking method

Other: Tryptophan

Interventions

Tryptophan OTHER

4 different tryptophan test levels 0.5, 1, 1.5 and 2 mg.kg-1.day.1

Also known as: maize

MA of tryptophan in maize

Eligibility Criteria

• Age: 60 Years - 90 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 60 to 90 years old.
• In good general health as evidenced by medical history, physical health and blood draw.
• Fasting blood glucose, hemoglobin A1c (HbA1c), urea, creatinine.
• Willingness to participate in the study.
• BMI \<30 kg/m2.

You may not qualify if:

• Presence of chronic disease and/or acute illness known to affect protein/amino acid metabolism (e.g. HIV, diabetes, taking medications known to affect protein/AA metabolism (e.g. steroids).
• Inability to tolerate the diet (i.e. allergy).
• Significant weight loss during the past month or consumption of weight reducing diets.
• Significant caffeine consumption (\>2 cups per day).
• Significant consumption of alcohol (\>1 drink per day i.e. 1 beer or ½ glass of wine).
• Unwilling to have blood drawn from a venous access or using a ventilated hood indirect calorimeter for the purposes of the study.

Sponsors & Collaborators

• The Hospital for Sick Children: lead

Study Sites (1)

The Hospital for Sick Children

Toronto, Ontario, M5G 1X8, Canada

Location

MeSH Terms

Interventions

Tryptophan

Intervention Hierarchy (Ancestors)

Amino Acids, Aromatic; Amino Acids, Cyclic; Amino Acids; Amino Acids, Peptides, and Proteins; Amino Acids, Essential

Study Officials

• Glenda Courtney Martin, PhD, RD

  The Hospital for Sick Children

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Scientist

Study Record Dates

• First Submitted: November 26, 2025
• First Posted: December 9, 2025
• Study Start: November 29, 2025
• Primary Completion: March 1, 2026
• Study Completion: May 2, 2026
• Last Updated: December 9, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)