Dietary Methionine and Cysteine Restriction in Healthy Adults

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02192437

Enrollment

Registered

2014-07-16

Start date

2014-07-16

Completion date

2017-07-31

Last updated

2020-09-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

methionine, cysteine, sulfur amino acid restriction

Brief summary

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

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.

Interventions

OTHERSulfur amino acid restricted diet

Methionine restricted diet: 70% or 90% restriction Methionine and cysteine restricted diet: 50% or 65% restriction

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

24 Years to 65 Years

Healthy volunteers

Yes

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)

Design outcomes

Primary

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

Secondary

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

Other

Measure	Time frame
Plasma IGF1, insulin	Baseline, four weeks

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026