New Study Says I Was Wrong About NMN and NR?

For weekly health research summaries and extra insights, sign up here 👉 https://drstanfield.com/pages/sign-up 🩺 Get your personalized health roadmap (free): https://drstanfield.com/pages/roadmap Timestamps: 00:00 The Discovery of Nicotinamide Riboside 01:22 NR vs NMN Debate 02:24 The New NR vs NMN (Bergen) Study 03:15 The Contradictory NR vs NN Nature Metabolism Study 03:51 The Hidden Truth in the Bervin Data 06:37 The Evidence Against NR and NMN 09:38 Conclusion & Key Takeaways ✔️ X: https://x.com/BradStanfieldMD ✔️ Patreon: https://www.patreon.com/bradstanfieldmd Here are the links to the research papers referenced in the video: Brenner 2004 (doi: 10.1016/S0092-8674(04)00416-7) — Discovery of NR as an NAD+ precursor in yeast and humans, establishing the NRK pathway. Brenner 2007 (doi: 10.1016/j.cell.2007.03.024) — NR extended yeast lifespan from ~13 to ~23 divisions via Sir2 silencing. Sinclair 2016 (doi: 10.1016/j.cmet.2016.09.013) — NMN in mice mitigated age-related decline: weight, energy, insulin sensitivity, eye function. Berven 2026 (doi: 10.1016/j.isci.2026.114764) — Phase I crossover trial (n=6): NR produced ~2.3x higher blood NAD increase vs NMN. Also showed elevated NAAD, implicating the Preiss-Handler pathway. Christen/Nature Metabolism 2025 (doi: 10.1038/s42255-025-01421-8) — RCT (n=65): NR and NMN comparably doubled NAD at 14 days; no significant difference between them. Ex vivo gut data showed NR rapidly converted to nicotinic acid by bacteria. Princeton 2022 (doi: 10.1016/j.cmet.2022.11.004) — Isotope-labeled NR tracing showed the primary route to host NAD is via gut microbiome conversion to nicotinic acid; antibiotic depletion completely eliminated this. Japanese 2025 (doi: 10.1126/sciadv.adr1538) — Even IV-administered NMN/NR was dumped into bile and converted to nicotinic acid by gut bacteria, bypassing the gut didn't help. Skeletal muscle meta-analysis 2025 (doi: 10.1002/jcsm.13799) — 10 RCTs in adults 60+: no significant effect on muscle mass, grip strength, gait speed, or chair stand. Concluded "negligible effect." Glucose/lipid meta-analysis (doi: 10.1007/s11892-024-01557-z) — 8 RCTs, 342 participants: no significant improvement in fasting glucose, insulin, HbA1c, or any lipid marker. Long-COVID RCT 2025 (doi: 10.1016/j.eclinm.2025.103633) — NR for 20 weeks tripled NAD levels in long-COVID patients; zero improvement in cognition, fatigue, sleep, anxiety, or depression. Exercise/NAD 2022 (doi: 10.1038/s43587-022-00174-3) — Exercise-trained older adults had NAD levels comparable to young people, suggesting NAD decline isn't inevitable. Thumbnail by James Kelly Video edited by Troy Young Script by John Milliken The content contained in this video, and its accompanying description, is not intended to replace viewers’ relationships with their own medical practitioner. Always speak with your doctor regarding the content of this channel, and especially before using any products, services, or devices discussed on this channel.