The Study
Glycine supplementation extends lifespan of male and female mice
This study saw that mice who ate extra glycine lived a little longer and got less lung cancer, but it didn't randomly assign them to groups or hide who got what. So we can't say glycine definitely caused the longer life—maybe something else was different.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists gave mice extra glycine (a harmless amino acid) in their food to see if it helped them live longer and stay healthier.
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 516 / 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.
- 1The effect is small — like adding a few extra weeks to a human’s 80-year life — but consistent and specific to lung cancer and longevity, not general health.
- 2Mice with extra glycine lived 4%-6% longer on average, had 78% fewer lung cancer deaths (2 vs.
- 39), and female mice stayed lighter, but no other diseases changed.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Aging Cell
Year
2019
Authors
Richard A. Miller, David E. Harrison, C. M. Astle, Molly A. Bogue, J. Brind, Elizabeth Fernandez, K. Flurkey, M. Javors, W. Ladiges, C. Leeuwenburgh, F. Macchiarini, James F. Nelson, Alexey G. Ryazanov, J. Snyder, T. Stearns, Douglas E. Vaughan, R. Strong
Related Content
Claims (6)
In mice with genetic variation, a diet containing 8% glycine was linked to fewer deaths from lung cancer compared to a normal diet, with 2 deaths in the glycine group versus 9 in the control group.
Female mice given 8% glycine in their diet lose 7% to 10% of their body weight between 12 and 24 months of age, while male mice given the same diet do not lose weight.
In a specific strain of mice, giving aspirin, inulin, or TM5441 starting at 11 months of age does not change how long the mice live on average or at their maximum lifespan.
In genetically heterogeneous mice, feeding a diet containing 8% glycine for 12 to 24 months is associated with a 4% to 6% longer median lifespan and a 6% longer maximum lifespan in males, and a 2% longer maximum lifespan in females, with consistent results across three separate research laboratories.
In mice with diverse genetics, a diet containing 8% glycine does not change the rate of 40 common age-related diseases such as tumors and degenerative conditions, but it is associated with longer lifespan and fewer pulmonary adenocarcinomas.
In animals, increasing the amount of glycine relative to methionine in the diet reduces the shortening of lifespan that occurs with high methionine intake.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.