Longevity & Aging · Diets
sirtuins enables caloric-restriction lifespan extension
In plain terms: Do sirtuins, the so-called 'longevity' proteins, explain why eating less extends life?
Part of: • Aging
Unclear — evidence is mixed, only in yeast and worms, and a careful study saw it largely vanish.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Population patterns (Observational)
How the studies fall
What the evidence shows
Foundational yeast/worm support (Guarente lab) that SIR2/SIRT1 mediate CR longevity, but the strong causal form is contested: Burnett 2011 found the prior overexpression effects collapse on controlled genetic backgrounds and DR can work independently of Sir2.
The evidence (14)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Bruner KR 2025 · Geroscience | mechanism | tested-null | low | Glucagon-receptor signaling was indispensable for the healthspan benefits of caloric restriction — identifies a NON-sirtuin mediator of CR benefits, arguing sirtuins are not the sole/necessary mediator (mixed for the sirtuin-mediation claim). |
| Wu LE 2023 · Aging Cell | animal | contradicts | moderate | SIRT2 transgenic overexpression did NOT impact lifespan in normal mice (benefit only in a progeria model) - undercuts sirtuins as general longevity mediators. |
| Rogina B 2024 · Front Genet | observational | supports | low | Review by a sirtuin proponent: SIRT1/resveratrol links to CR and aging, but acknowledges contested resveratrol/SIRT1 lifespan data - net supportive-but-qualified. |
| Lin 2000 · Science | animal | supports | moderate | CR-induced lifespan extension in yeast requires SIR2 and NAD synthesis (NPT1) |
| Yang H 2007 · Aging Cell | animal | supports | low | Designed STAC compounds activating Sir2 extended yeast replicative lifespan, reinforcing the sirtuin-activation route to lifespan extension (in-vitro/yeast). |
| Maissan P 2021 · Biology (Basel) | mechanism | supports | low | Systematic review: sirtuin activity extends lifespan across organisms via NAD+-dependent regulation at the metabolism/cell-cycle interface (supportive synthesis). |
| Tissenbaum 2001 · Nature | animal | supports | moderate | Extra copy of sir-2.1 extends C. elegans lifespan up to 50%, upstream of daf-16 |
| Wu P 2025 · J Gerontol A Biol Sci Med Sci | animal | supports | moderate | C. elegans axenic dietary restriction: large lifespan extension shown to genetically require sir-2.1 — direct evidence sirtuins mediate a caloric/dietary-restriction longevity effect (invertebrate). |
| Qu Q 2025 · Nature | animal | supports | high | Lithocholic acid (accumulated during CR) binds TULP3 to activate sirtuins and AMPK and slow ageing in mice - recent mechanistic support linking CR to sirtuin activation. |
| Lin SJ 2004 · Genes Dev | animal | supports | moderate | CR extends yeast replicative lifespan by lowering NADH and activating the NAD-dependent deacetylase Sir2 - core mechanistic support for sirtuin-mediated CR longevity. |
| Wood 2004 · Nature | animal | supports | moderate | Sirtuin-activating compounds (STACs) mimicked CR and delayed ageing in yeast, worms and flies in a Sir2-dependent manner, supporting sirtuins as CR effectors. ⚠️ correction-on-file (Crossref) - kept, corrigendum not retraction |
| Brenner C 2022 · Life Metab | observational | contradicts | moderate | Argues sirtuins are NOT conserved longevity genes; cross-species lifespan claims fail the conservation test - directly contests the CR-sirtuin thesis. |
| Burnett 2011 · Nature | animal | contradicts | high | With controlled genetic background, Sir2 overexpression does NOT extend lifespan in worms/flies; DR works independently of dSir2 |
| Moroz N 2014 · Aging Cell | animal | supports | moderate | Dietary restriction acted through NAD+-dependent (sirtuin) mechanisms and an oxidative-metabolism shift, supporting sirtuin involvement in DR longevity (independent lab). |
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