Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial.

Study answer

What this study found

GlyNAC produced broad, clinically meaningful improvements in older adults, whereas placebo did not. Over 16 weeks, insulin resistance fell substantially, with HOMA-IR down 31% at 2 weeks and 64% at 16 weeks, and fasting insulin down 34% and 65%, respectively. Inflammation and endothelial markers also improved, including IL-6 down 57% at 2 weeks and 78% at 16 weeks, TNF-alpha down 30% and 54%, hs-CRP down 25% and 41%, sICAM-1 down 27% and 57%, and sVCAM-1 down 21% and 44%. Oxidative stress and mitochondrial measures improved as well, with 8-OHdG decreasing by 57% at 2 weeks and 73% at 16…

Study & population

This was a randomized controlled clinical trial in older adults with overweight BMI criteria (> 27) and no major confounding diseases.

Intervention

Older adults received oral GlyNAC capsules containing glycine 100 mg/kg/day plus N-acetylcysteine 100 mg/kg/day once daily for 16 weeks.

Key limitation

The active arm was small, with only 12 older adults, which limits precision and generalizability.

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Original abstract