This is a randomized study on healthy individuals. The study design includes the recruitment of 12 healthy male and female subjects (50-80 yr of age) randomized into 2 groups of 6 each (liposomal glutathione at 500 mg/day or liposomal glutathione at 1000 mg/day). Blood and urine samples will be obtained from all subjects 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, liposomal glutathione (500 mg daily), Group B, liposomal glutathione (1000 mg daily)
Eligible participants who sign the informed consent will be randomly assigned to either low dose or high 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 liposomal glutathione between subjects. Participants are to limit their consumption of alcohol in the study to no more than 5 oz. of alcohol per week. Supplementation will continue for 1 month with biological samples collected at 1, 2 and 4 weeks after baseline.
Levels of glutathione will be measured in whole blood, erythrocytes, lymphocytes and plasma. The biomarkers of oxidative stress will include urinary 8-isoprostane and urinary 8-hydroxydeoxyguanosine. Immune function biomarkers will be analyzed including lymphocyte proliferation and natural killer (NK) cell cytotoxicity.
