Enhanced Glutathione Levels in Blood and Buccal Cells by Oral Glutathione Supplementation

Abstract

Glutathione (GSH) is the major antioxidant in nearly all cells and plays numerous roles in protection against diseases and biological insults. Previous studies in laboratory animals indicate that orally administered GSH is bioavailable and effective at enhancing tissue GSH levels. The current objective was to determine the efficacy of GSH supplementation at enhancing body stores of GSH in healthy adults. We conducted a 6‐mo randomized, double‐blind, placebo controlled trial to determine the impact of GSH administration at 250 mg/day and 1000 mg/day on GSH levels in different blood components and exfoliated buccal mucosal cells. Subjects were 54 healthy adults (41 females/13 males), 28–72 yr of age (mean=46.6 yr). Compliance was >;90% by pill count. After 6 mo in the high dose group, GSH levels were increased 30–35% in RBC, plasma, and lymphocytes and 260% in buccal cells (P<0.05). In most cases, the increases were dose and time dependent and levels returned to baseline after a 1‐month washout. No significant changes were observed in levels of protein bound GSH. A battery of immune function markers was also examined after 3 mo of GSH supplementation and Natural Killer (NK) cytotoxicity was enhanced >; 2‐fold in the high dose group (P<0.05). Altogether, these findings are consistent with previous pre‐clinical studies and indicate that long‐term oral administration GSH is an effective means of enhancing body stores of GSH.