Oral Glutathione Supplementation on the Levels of Blood Glutathione

Not Applicable

Completed

• Conditions: Healthy Adults
• Interventions: Drug: Glutathione supplementation; Drug: Gluthathione peroxidases; Other: Placebo

• Registration Number: NCT01044277
• Lead Sponsor: Milton S. Hershey Medical Center

Brief Summary

This trial is designed to provide evidence of the efficacy of glutathione supplementation and health(GSH) and includes the assessment of both short term and long term effects. Based on previous laboratory animal studies and clinical data, the investigators anticipate that the effects of oral GSH supplementation will be progressive and cumulative. The study will also allow for the evaluation of effects of withdrawal of the supplement on the outcome variables.

Detailed Description

This is a randomized double-blind, placebo-controlled study in which the treatment allocations will be kept sealed until the final statistical evaluation. The design will include the recruitment of 60 healthy subjects (30-79 yr of age) randomized into 3 groups. A total of 48 subjects, 16 per group will be required based upon power calculations and results from a previous clinical trial with selenium. An additional 4 subjects per group will be placed on trial to account for possible attrition or non-compliance. Blood, urine and exfoliated buccal mucosal samples will be obtained from all subjects at baseline. Questionnaire data on usual dietary intake will also be obtained at baseline. Eligible subjects will be required to have not have taken any high dose antioxidant supplements for at least 1 month prior to the study. Subjects will then begin supplementation according to the following schedule:

Group A, GSH (500 mg, 2 times daily); Group B, GSH (125 mg, 2 times daily); Group C, placebo (2 times daily). Eligible participants who sign the informed consent will be randomly assigned to either placebo or high or low dose Glutathione groups. Participants will be asked not to consume any other high-dose vitamin, multi-vitamin, or mineral supplements containing glutathione throughout the study in order to prevent variation in dose of supplemental GSH between subjects. Supplementation will continue for 6 months with biological samples collected at 1, 3 and 6 months after baseline. At 6 months, supplementation will be discontinued. A final collection of biological samples will occur 1 month afterwards. Compliance will be monitored by pill count.

Levels of glutathione will be measured in plasma, lymphocytes, and red blood cells as well as in exfoliated buccal mucosal cells. Biomarkers of oxidative stress will include blood levels of glutathionylated proteins and 8-isoprostanes and urine levels of 8-hydroxydeoxyguanosine. Glutamylcystine ligase and GST activities, and C-reactive protein will be determined in blood. Immune function biomarkers will be analyzed including t-natural killer cell cytotoxicity, lymphoproliferation, neutrophils phagocytosis, neutrophil respiratory burst assays.

Study Timeline

• Study First Submitted: 2010-01-06
• Study First Submitted QC: 2010-01-06
• Study First Posted: 2010-01-07
• Study Start: 2010-02
• Primary Completion: 2011-09
• Study Completion: 2014-10
• Status Verified: 2022-08
• Last Update Submitted: 2022-08-31
• Last Update Posted: 2022-09-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 61

Inclusion Criteria

• Healthy male and females between the ages of 30 and 79 years of age
• Not taking glutathione as a dietary supplement
• Not taking high dose antioxidant supplement prior to 1 month
• Baseline blood glutathione level of < 1 mmol/L

Exclusion Criteria

• History or evidence of disease including cancer, diabetes, heart disease
• Subjects who smoke

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group A	Glutathione supplementation	Glutathione supplementation-Double-Blind - GSH 500 mg/GSH 125 mg/Placebo Other name Gluthathione peroxidases
Group B	Gluthathione peroxidases	Glutathione supplementation-Double-Blind - GSH 500 mg/GSH 125 mg/Placebo Other name Gluthathione peroxidases
Group C	Placebo	Placebo-Double-Blind - GSH 500 mg/GSH 125 mg/Placebo

Primary Outcome Measures

Name	Time	Method
Evaluation of the effect of glutathione on key biomarkers	6 to 7 months	Blood glutathione status

Secondary Outcome Measures

Name	Time	Method
Evaluations will be carried out to expand the above comparison by including adjustments for potential prognostic factors.	6 to 7 months	Biomarkers of oxidative stress and immune function

Trial Locations

Locations (1)

Penn State Milton S. Hershey Medical Center; 🇺🇸 Hershey, Pennsylvania, United States