Dietary Methionine and Cysteine Restriction in Healthy Adults

Penn State Health

Status: Completed

Conditions: Healthy

Treatments: Other: Sulfur amino acid restricted diet

Study type: Interventional

Funder types: Other

Identifiers

NCT02192437

03-13-2014

Details and patient eligibility

About

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 .

Full 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.

Enrollment: 20 patients

Sex: All

Ages: 24 to 65 years old

Volunteers: Accepts Healthy Volunteers

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)

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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20 participants in 2 patient groups

Methionine restricted diet

Experimental group

Description:

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.

Treatment:

Other: Sulfur amino acid restricted diet

Methionine and cysteine restricted diet

Experimental group

Description:

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.

Treatment:

Other: Sulfur amino acid restricted diet