Glycine and N-acetylcysteine (GlyNAC) supplementation in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, insulin resistance, endothelial dysfunction, genotoxicity, muscle strength, and cognition
Introduction
This pilot clinical trial suggests that GlyNAC supplementation could play a valuable role in supporting longevity. By increasing glutathione levels – the body’s master antioxidant – this combination of glycine and N-acetylcysteine (NAC) helped older adults reduce oxidative stress, enhance mitochondrial function, and improve cognitive function, muscle strength, and metabolic health. When supplementation stopped, these benefits started to diminish.
What did the study examine?
As we get older, our bodies undergo gradual changes that can negatively impact cellular function, increasing oxidative stress, mitochondrial dysfunction, and inflammation. These factors contribute to common age-related concerns like insulin resistance, muscle loss, and cognitive impairment.
The researchers sought to answer the following question: Can GlyNAC supplementation counteract age-related decline and improve overall health?
To explore this, they conducted a 36-week open-label clinical trial with two groups:
- 8 older adults (ages 71-80) who took GlyNAC for 24 weeks, followed by a 12-week washout period.
- 8 younger adults (ages 21-30) serving as a reference group.
Findings
Older adults supplementing with GlyNAC experienced significant improvements across multiple physiological functions:
Cellular and metabolic health
- Glutathione levels rose by 200%, restoring them to levels comparable to younger adults.
- Oxidative stress markers fell by 75%, indicating reduced cellular damage.
- Mitochondrial function significantly improved, boosting energy metabolism.
Inflammatory markers
- IL-6 decreased by 77%, a key driver of chronic inflammation.
- TNFα dropped by 57%, lowering systemic inflammation.
- CRP levels declined by 49%, a sign of reduced chronic inflammation.
Cognitive performance and brain health
- Scores on the Montreal Cognitive Assessment (MoCA) improved, indicating better cognition.
- Brain-derived neurotrophic factor (BDNF) increased, a key neurotrophic factor associated with cognitive function and memory.
Physical performance and strength
- Gait speed increased, a clinically recognised marker of mobility and functional independence.
- Grip strength improved in both dominant and non-dominant hands.
- Stamina and endurance increased in a 6-minute walk test.
Metabolic and cardiovascular health
- Insulin resistance dropped by 59%, suggesting enhanced glucose regulation.
- Vascular function improved, supporting heart and circulatory health.
- Reductions in waist circumference and body fat were observed.
What happened after GlyNAC was discontinued?
After 12 weeks without GlyNAC, many of these improvements began to diminish, indicating that consistent supplementation may be needed to sustain these benefits.
Why is this important?
While ageing is inevitable, how we age depends on cellular function. GlyNAC supplementation appears to support several critical aspects of healthy ageing, including oxidative stress management, mitochondrial function, inflammation control, and cognitive health. GlyNAC was found to be safe and well-tolerated, with no reported adverse effects.
