Longevity & Aging
Does a key cellular energy molecule fall with age?
The claim, precisely: aging decreases cellular NAD+
Strong support Longevity & Aging
RefutedContestedStrong support
consensus score 0.73
Yes, agreed across many labs, though it's an observed link and the human drop varies by tissue.
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)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
12 support 0 contradict 0 tested null 3 mixed · 15 sources, 12 independent groups
What the evidence shows
Tissue/blood NAD+ falls with age across multiple independent labs - one of Sinclair's better-evidenced premises, though the human magnitude is heterogeneous and tissue-specific (more robust in rodents).
The evidence (15)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Migliavacca 2019 · Nat Commun | observational | supports | moderate | Muscle NAD+ biosynthesis (NAMPT) and mitochondrial capacity reduced in human sarcopenia across three independent cohorts (n=119) |
| Benjamin 2024 · Nutrients | observational | mixed | low | Reviews NMN trials; notes age-related NAD+ decline is real but human magnitude is variable and inconsistently measured |
| Yusri 2025 · npj Metab Health Dis | mechanism | supports | low | Review synthesizing multi-lab evidence that tissue NAD+ metabolism declines with age and modulates mitochondrial function |
| Zhu 2018 · Front Aging Neurosci | observational | supports | low | In-vivo 31P-MRS finds intracellular NAD+ and NAD+/NADH redox decline in the aging human brain |
| Katsyuba 2018 · Nature | animal | supports | moderate | De novo NAD+ synthesis (ACMSD inhibition) raises NAD+ and improves mitochondrial function - supports functional importance of declining NAD+ |
| Chini 2020 · Nat Metab | animal | supports | moderate | CD38 ecto-enzyme rises in aging immune cells and drives age-related NAD+ and NMN decline - mechanism for tissue NAD+ fall |
| Tran 2022 · JAIDS | observational | supports | low | [FT-verified] JAIDS 2022 muscle NAD decline driven by HIV/HCV/CMV NOT age; tangential confounded-by-infection |
| Roichman 2021 · Nat Commun | animal | mixed | moderate | SIRT6 over-expression restores NAD+-linked energy homeostasis and extends healthy lifespan in mice - supports declining NAD+ economy with age |
| Cuenoud 2020 · Front Aging Neurosci | observational | supports | moderate | In-vivo 31P-MRS shows brain NAD declines and tracks ATP production in humans - independent human measurement of NAD decline |
| Oblong 2020 · Aging Cell | observational | supports | low | Aging human skin shows declining mitochondrial/metabolic output; nicotinamide restores integrity - consistent with cutaneous NAD+ decline |
| Bertoldo 2020 · Cell Rep | animal | supports | moderate | Oocyte NAD+ falls with reproductive aging in mice; NAD+ repletion rescues fertility - tissue-specific age decline |
| de Picciotto 2016 · Aging Cell | animal | supports | moderate | NMN supplementation reverses age-associated vascular dysfunction in mice, consistent with an age-related NAD+ deficit |
| Elhassan 2019 · Cell Rep | RCT | mixed | moderate | [FT-verified] Elhassan 2019 NR RCT raises muscle NAD+ but human age-decline data sparse; indirect |
| Chubanava 2023 · Exp Gerontol | mechanism | supports | low | [FT-verified] Chubanava 2023 REVIEW citing PRECLINICAL NAD decline not observational; regrade->mechanism ANIMAL-derived |
| Massudi 2012 · PLoS ONE | observational | supports | moderate | [FT-verified] Massudi 2012 direct human tissue NAD+ neg correlated with age + PARP/oxidative link |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.