Longevity & Aging
Does falling cell fuel scramble how cells power themselves with age?
The claim, precisely: cellular NAD+ attenuates nuclear-mitochondrial communication
No — it held in mice, but human trials that raised the molecule showed no benefit.
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: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
Sinclair's Gomes-2013 mechanism: age-related NAD+ DECLINE induces a pseudohypoxic HIF-1a state disrupting nuclear-mitochondrial OXPHOS communication. Real in mice; independent human RCTs that raised muscle NAD did NOT reproduce the predicted mitochondrial rescue.
The evidence (12)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Remie 2020 · Am J Clin Nutr | RCT | mixed | moderate | Independent human RCT: NR raised muscle acetylcarnitine but did not improve mitochondrial/metabolic function as the mechanism predicts |
| Elhassan 2019 · Cell Rep | RCT | contradicts | high | NR raised aged-muscle NAD+ metabolome but did NOT alter mitochondrial bioenergetics; downregulated mito pathways - predicted human mito benefit absent. |
| Dollerup 2020 · J Physiol | RCT | contradicts | moderate | Independent human RCT: 12wk NR did not alter muscle NAD metabolites, mitochondrial respiration, content or morphology |
| Gomes 2013 · Cell | animal | supports | moderate | Origin: NAD+ decline induces pseudohypoxic HIF-1a state disrupting nuclear-mito OXPHOS; reversed by raising NAD+ in old mice (SIRT1-dependent) |
| Zhang H 2016 · Science | animal | supports | high | NAD+ repletion (NR) restored mitochondrial function & muscle stem-cell rejuvenation and extended lifespan in aged mice, supporting the NAD->mito-communication mechanism. |
| Ahmadi 2023 · JCI Insight | RCT | contradicts | moderate | RCT of NR (and CoQ10) in CKD: no improvement in VO2peak or work efficiency vs placebo despite mitochondrial-targeting rationale. |
| Whitson JA 2020 · Aging Cell | animal | supports | moderate | NMN normalized age-related cardiac energetic (PCr/ATP) decline and increased NAD+ under workload in old mouse hearts, supporting NAD-dependent mito communication. |
| Martens 2018 · Nat Commun | RCT | mixed | moderate | Chronic NR raised NAD+ and was well tolerated but produced no broad physiological/mitochondrial benefit; only a suggestive BP/arterial-stiffness signal. |
| Dollerup 2018 · Am J Clin Nutrition | RCT | contradicts | high | 12wk NR in obese insulin-resistant men: no improvement in insulin sensitivity, mitochondrial or metabolic parameters despite NAD+ precursor delivery. |
| Dollerup OL 2019 · J Clin Endocrinol Metab | RCT | contradicts | moderate | NR in nondiabetic men with obesity did not affect beta-cell/alpha-cell function or incretin secretion; predicted NAD/SIRT1 metabolic benefit not seen. |
| Chen 2024 · Current Diabetes Reports | meta-analysis | contradicts | moderate | Meta-analysis of 8 NMN RCTs: no significant benefit on fasting glucose, insulin, HbA1c, HOMA-IR or lipids - human metabolic effect of raising NAD+ unsupported. |
| Prokopidis 2025 · J Cachexia Sarcopenia Muscle | meta-analysis | contradicts | moderate | Meta-analysis: NMN/NR showed no significant effect on muscle mass index, grip strength or gait speed in older adults - predicted muscle/mito benefit absent. |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.