Glutathione and immune function

Understanding exactly how glutathione supports immune function at the cellular level is critical for clinical application. This authoritative review by Droge and Breitkreutz, published in the Proceedings of the Nutrition Society, laid out the mechanistic foundations.

The authors synthesized evidence from multiple human and animal studies examining the relationship between intracellular glutathione concentrations and immune cell function. They focused particularly on lymphocyte activity, NK cell cytotoxicity, and the T-cell response, examining how GSH depletion and repletion affect these critical immune parameters.

The review established a key principle: lymphocytes require balanced intermediate GSH levels for optimal function, and even moderate changes in intracellular glutathione profoundly affect their activity. In immunocompromised patients with documented cysteine and GSH deficiency, NAC treatment nearly completely restored NK cell activity across two randomized controlled trials. Importantly, healthy individuals with normal GSH levels showed less dramatic improvements, suggesting the greatest benefit comes from correcting deficiency rather than pushing levels above normal.

This work provides the mechanistic rationale for glutathione optimization in clinical practice. For patients with compromised immunity — whether from aging, chronic illness, or environmental stress — ensuring adequate GSH levels may be one of the most impactful interventions available. The dose-response relationship also guides clinical decision-making: test, replete if deficient, and monitor response.