Metabolic Availability of Tryptophan From White Maize

NCT02402179 | Completed

• 1 other identifier: 1000048461
• Study Type: interventional
• Target: 7
• Locations: 1 country
• Sites: 1

Brief Summary

Our objective is to determine the metabolic availability of Tryptophan in white maize using the indicator amino acid oxidation (IAAO) technique in adult men.

Conditions

Healthy

Keywords

protein quality

Outcome Measures

Primary Outcomes (1)

• Metabolic Availability of Tryptophan in Corn

  The quality of corn protein will be assessed by measuring the amount of its tryptophan available for protein synthesis (metabolic availability) using the slope ration method. The oxidation of the indicator amino acid phenylalanine will be measured in response to feeding graded intakes of tryptophan in a reference protein patterned after egg protein, and provided as a crystalline amino acid mixture. The pattern of oxidation of phylalanine in response to tryptophan provided in corn will be compared to the pattern of oxidation obtained from feeding the reference protein. On each study day, subjects will be fed 8 hourly meals and breath samples will be taken to measure the oxidation of phenylalanine. Samples will be collected at baseline after the fourth meal, and half hourly, beginning 2.5 hrs after the 5th meal. Breath samples will be analyzed for 13CO2 enrichment.

  9 hours

Study Arms (1)

Tryptophan Amino Acid

EXPERIMENTAL

13.2, 26.4, 39.7, 52.9% of the mean tryptophan requirement of 3.78 mg/kg/d will be given to subjects.

Other: Tryptophan

Interventions

Tryptophan OTHER

Tryptophan will be supplied at 13.2, 26.4, 39.7, or 52.9% of requirement; sourced from crystalline amino acid and white cornmeal maize.

Tryptophan Amino Acid

Eligibility Criteria

• Age: 20 Years - 49 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy Adult males (20-49years old).
• Stable body weight
• Not on any medications that could affect protein and amino acid metabolism e.g. steroids.

You may not qualify if:

• Recent weight loss within the last 3 months or on weight reducing diet.
• Unwillingness to participate or unable to tolerate the diet.

Sponsors & Collaborators

• The Hospital for Sick Children: lead

Study Sites (1)

The Hospital for Sick Children

Toronto, Ontario, Canada

Location

Related Publications (1)

• Rafii M, Elango R, Ball RO, Pencharz PB, Courtney-Martin G. Metabolic Availability of the Limiting Amino Acids Lysine and Tryptophan in Cooked White African Cornmeal Assessed in Healthy Young Men Using the Indicator Amino Acid Oxidation Technique. J Nutr. 2018 Jun 1;148(6):917-924. doi: 10.1093/jn/nxy039.

  PMID: 29741697 DERIVED

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

• Paul Pencharz, MD, PhD,

  Senior Scientist

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: HEALTH SERVICES RESEARCH
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor, Faculty of Kinesiology and Physical Education, U of Toronto; Project Investigator, Research Institute The Hospital for Sick Children

Study Record Dates

• First Submitted: March 19, 2015
• First Posted: March 30, 2015
• Study Start: March 1, 2015
• Primary Completion: April 1, 2016
• Study Completion: May 1, 2016
• Last Updated: November 15, 2016

Record last verified: 2016-11

Locations

CA (1)