Tier 4 — mechanistic

Plasma glycine decelerates biological aging via the redox-inflammatory axis: A large-scale study modulated by sex and dietary patterns

Xu H, Pan S, Qi H, Liu X, Geng G, Qi X, Wei W, Li Y, Wang X
Free radical biology & medicine 2026 252:286-294

Bibliography

PubMed
PMID 42105789
DOI
10.1016/j.freeradbiomed.2026.04.163
Funding
Indexed support: Harbin Medical University. See the publication for grant and funder details.
Competing interests
The accessible abstract does not establish the authors' competing interests; absence of a statement is not evidence of no conflicts.

Study snapshot

DesignHuman observational study
ModelAdult humans
SampleLarge UK Biobank analysis; exact analytic n not specified in the indexed abstract
InterventionMeasured plasma glycine related to biological-age metrics and diet; no glycine intervention
DurationObservational analysis; no dosing period
EndpointsKlemera-Doubal biological-age residuals; Redox and inflammatory markers; Sex-by-diet interactions

What the study showed, in plain terms

Despite its causal-sounding title, this 2026 paper reports associations between plasma glycine and biological-aging metrics. It does not show that glycine supplements slow aging.

Key findings

  • Higher glycine correlated with lower KDM residuals.
  • Statistical mediation and sex-specific diet interactions were reported.

What this study can and cannot tell us

Observational mediation cannot establish a causal redox-inflammatory mechanism.

Biological-age associations are not demonstrated lifespan or healthspan benefits from supplementation.

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Glycine ameliorates aging-related dysfunctions associated with Nmdmc-mediated mitochondrial one-carbon metabolism
Yu J et al. · Free radical biology & medicine · 2026
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Mechanisms of amino acid-mediated lifespan extension in Caenorhabditis elegans
Edwards C et al. · BMC genetics · 2015
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The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review
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Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction