The Study
Glycine promotes longevity in Caenorhabditis elegans in a methionine cycle-dependent fashion
This study found that when scientists gave glycine to tiny worms, the worms lived longer and their genes acted differently. But this doesn't mean glycine will do the same thing in people — it only shows what happened in these specific worms under lab conditions.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists found that giving tiny worms extra glycine or serine makes them live longer, but only if given right after they become adults.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 514 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This was tested in worms, not humans — so it doesn't prove the same effect happens in people, but it suggests a biological pathway that might be relevant.
- 2Glycine made worms live 19.2% longer; serine made them live 20.8% longer.
- 3These effects only happened when given during the first 3 days of adulthood.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PLoS Genetics
Year
2018
Authors
Yasmine J. Liu, G. Janssens, Rashmi Kamble, Arwen W. Gao, A. Jongejan, M. V. Weeghel, Alyson W. MacInnes, R. Houtkooper
Related Content
Claims (5)
In animals, increasing the amount of glycine relative to methionine in the diet reduces the shortening of lifespan that occurs with high methionine intake.
Adding glycine to the diet of the nematode Caenorhabditis elegans at concentrations between 5 and 500 micromolar increases its median lifespan by up to 19.2% in laboratory settings, and this increase depends on the function of two specific enzymes involved in one-carbon metabolism.
In the worm Caenorhabditis elegans, supplementation with glycine and serine reduces the activity of thousands of genes related to growth and development, and this reduction is associated with extended lifespan through decreased anabolic activity.
Adding serine at a concentration of 5 mM increases the average lifespan of the nematode Caenorhabditis elegans by 20.8%, and this effect requires the same enzymes involved in glycine’s lifespan extension, suggesting both amino acids act through a shared metabolic pathway related to one-carbon metabolism.
During aging in the worm Caenorhabditis elegans, glycine builds up because genes that break down glycine become less active, not because more glycine is made.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.