Dietary Methionine and Cysteine Restriction in Healthy Adults

Study Overview
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Brief Summary
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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 .

Detailed Description
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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.

Official Title
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Dietary Methionine and Cysteine Restriction in Healthy Adults

Conditions
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Healthy

Intervention / Treatment
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* Other: Sulfur amino acid restricted diet


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 24 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Methionine restricted diet<br>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<br>* Methionine restricted diet: 70% or 90% restriction Methionine and cysteine restricted diet: 50% or 65% restriction<br>|
| Experimental: Methionine and cysteine restricted diet<br>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<br>* Methionine restricted diet: 70% or 90% restriction Methionine and cysteine restricted diet: 50% or 65% restriction<br>|

What is the study measuring?
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Primary Outcome Measures

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

Secondary Outcome Measures

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

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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methionine, cysteine, sulfur amino acid restriction