MA of Tryptophan in Cornmeal in Healthy Adults>60y

November 26, 2025 updated by: Glenda Courtney-Martin, The Hospital for Sick Children

Metabolic Availability of Tryptophan in Cornmeal in Healthy Adults >60 Yrs

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Protein quality evaluation assesses the capacity of food proteins to meet the EAA needs of the body. The DPQ of plant proteins have been little studied in humans despite their importance in the diet and their well-recognized positive effects on chronic diseases. Dietary guidelines are encouraging increased plant protein consumption due to the benefits of plant protein. With the increasing interest in vegetarian diets in North America, it is imperative that the DPQ of cereal grains be evaluated so that plant protein recommendations are accompanied by an empirical understanding of plant protein quality. The information gathered from this project will provide additional experimental data in humans on plant protein quality (have completed lentils and chickpeas), on which nutrition recommendations can be built. Globally, this will also help support the FAO's commitment to compile tables on AABA of foods for global distribution. The aim of the study is to apply the IAAO method to determine the MA of tryptophan in maize prepared by moist cooking method.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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
      • Toronto, Ontario, Canada, M5G 1X8
        • The Hospital for Sick Children

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: MA of tryptophan in maize
Apply the IAAO method to determine the metabolic availability of tryptophan in maize prepared by moist cooking method
Other: Tryptophan
4 different tryptophan test levels 0.5, 1, 1.5 and 2 mg.kg-1.day.1
Other Names:
  • maize

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
MA of tryptophan in maize
Time Frame: Up to 24 months
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

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The Hospital for Sick Children

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Glenda Courtney Martin, PhD, RD, The Hospital for Sick Children

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 29, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 2, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 26, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 26, 2025

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 9, 2025

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 9, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 26, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 3568

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

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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