Dietary Methionine and Cysteine Restriction in Healthy Adults

Studies in laboratory models indicate that dietary methionine restriction (MR) enhances longevity and produces short- and long-term metabolic changes that are consistent with a healthy lifespan. The present study was designed to establish levels of dietary methionine or methionine and cysteine that induce physiological changes in healthy adults like those observed in rodent studies .

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: Sulfur amino acid restricted diet

Detailed Description

In this controlled feeding study, subjects will be randomized to one of two experimental. Group A (N=10): will start with control diet (31 mg/kg/day Met; 31 mg/kg/day Cys) for 4 weeks followed by a washout for 3-4 weeks, then a 70% MR diet (9.3 mg/kg/day Met; 40.3 mg/kg/day SAA) for 4 weeks, followed by 3-4 weeks washout period and then a 90% MR diet (3.1 mg/kg/day Met; 34.1 mg/kg/day SAA) for 4 weeks. Group B (N=10): will start with control diet (31 mg/kg/day Met; 31 mg/kg/day Cys) for 4 weeks followed by a washout for 3-4 weeks then a 50% methionine and cysteine restricted (M/CR) diet (15.5 mg/kg/day Met; 15.5 mg/kg/day Cys; 31 mg/kg/day SAA), followed by 3-4 weeks washout period and then a 65% M/CR diet (10.8 mg/kg/day Met; 10.8 mg/kg/day Cys; 21.6 mg/kg/day SAA) for 4 weeks.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • State College, Pennsylvania, United States, 16802
      • Penn State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 24 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Healthy English speaking male and female volunteers
• May or may not be students
• Age range 24-65 years
• Subjects will need to be of normal weight or moderately overweight (BMI 18.5-35 kg/m2)
• Subjects will be non-smokers

Exclusion Criteria:

• No use of medications known to impact the biomarkers of interest
• Pregnancy and lactating women
• Persons with documented diabetes
• No use of high dose dietary antioxidant supplements or fish oil/flax seed oil for n-acetylcysteine for at least 1 month prior to the study
• Use of tobacco products over the past 6 months
• Unstable weight
• Individuals with allergies to eggs, wheat, nuts, soy and latex
• Individuals with phenylketonuria (PKU)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Methionine restricted diet; Intervention will be a Sulfur amino acid restricted diet (methionine). Control diet for 4 weeks followed by a washout for 3-4 weeks, then a methionine restricted diet (70%) for 4 weeks, followed by 3-4 weeks washout period and then a methionine restricted diet (90%) for 4 weeks.	Other: Sulfur amino acid restricted diet; Methionine restricted diet: 70% or 90% restriction Methionine and cysteine restricted diet: 50% or 65% restriction
EXPERIMENTAL: Methionine and cysteine restricted diet; Intervention will be a Sulfur amino acid restricted diet (methionine and cysteine). Control diet for 4 weeks followed by a washout for 3-4 weeks then a methionine and cysteine restricted diet (50%) followed by 3-4 weeks washout period and then a methionine and cysteine restricted diet (65%) for 4 weeks.	Other: Sulfur amino acid restricted diet; Methionine restricted diet: 70% or 90% restriction Methionine and cysteine restricted diet: 50% or 65% restriction

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Body weight, plasma sulfur amino acids	Baseline, four weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Biomarkers of oxidative stress, blood lipids	Baseline, four weeks

Other Outcome Measures

Outcome Measure	Time Frame
Plasma IGF1, insulin	Baseline, four weeks

Collaborators and Investigators

• Sponsor: Milton S. Hershey Medical Center
• Collaborators: Orentreich Foundation for the Advancement of Science, Inc.
• Investigators: Principal Investigator: John P Richie, PhD, Penn State University; Principal Investigator: Sailendra Nichenametla, Ph.D., Orentreich Foundation for the Advancement of Science, Inc.

Study record dates

Study Major Dates

• Study Start (ACTUAL): July 16, 2014
• Primary Completion (ACTUAL): July 1, 2016
• Study Completion (ACTUAL): July 1, 2017

Study Registration Dates

• First Submitted: July 14, 2014
• First Submitted That Met QC Criteria: July 14, 2014
• First Posted (ESTIMATE): July 16, 2014

Study Record Updates

• Last Update Posted (ACTUAL): September 7, 2020
• Last Update Submitted That Met QC Criteria: September 4, 2020
• Last Verified: September 1, 2020

More Information

Terms related to this study

• Keywords: methionine; cysteine; sulfur amino acid restriction
• Other Study ID Numbers: 03-13-2014