A major review paper just dropped in Nature Aging (March 24, 2026). More than 25 scientists from the University of Oslo, Akershus University Hospital, and international collaborators published a comprehensive analysis of NAD+ metabolism and its role in aging, Alzheimer's, and Parkinson's disease.
This isn't a supplement company blog post. This is the scientific community putting its full weight behind the idea that NAD+ augmentation could change how we age.
Here's what they actually found — and what it means for your protocol.
What Is NAD+ and Why Does It Decline?
NAD+ (nicotinamide adenine dinucleotide) is called the cell's "fuel regulator." It's involved in:
- Energy production (ATP synthesis in mitochondria)
- DNA repair (PARP enzyme activation)
- Cellular stress response (SIRT1-7 sirtuins)
- Circadian rhythm regulation
- Inflammation modulation
The problem: NAD+ levels decline approximately 50% between ages 40 and 60. This drop has been linked to memory problems, reduced muscle strength, metabolic dysfunction, and a higher risk of age-related neurodegenerative diseases.
The question the Nature Aging review tried to answer: can we reverse this decline, and does reversing it actually help?
The Nature Aging 2026 Review: Key Findings
Source: University of Oslo + 25 international scientists, Nature Aging, published March 24, 2026
1. NAD+ and Neurodegeneration (Alzheimer's + Parkinson's)
This is the headline finding. The review identifies NAD+ augmentation as a promising avenue for both Alzheimer's and Parkinson's prevention — not treatment, but prevention and slowing of progression.
The mechanism: NAD+ supports mitochondrial health in neurons. In both Alzheimer's and Parkinson's, mitochondrial dysfunction is a core pathology. Maintaining higher NAD+ levels may reduce this dysfunction and the resulting neuroinflammation.
2. Memory, Movement, Metabolic Health — Early Human Data
The review summarizes multiple clinical trials showing improvements in:
- Memory and cognitive function (mild improvements in MCI patients)
- Physical performance and muscle function (particularly in older adults)
- Metabolic markers (insulin sensitivity, lipid profiles)
Key expert quote: "Fine-tuning NAD+ metabolism holds promise for delaying age-related health decline as well as disease such as premature ageing diseases. But to truly unlock its potential, we need to better understand the right doses, long-term safety, and interindividual variability." — Dr. Jianying Zhang, lead author
3. The Open Questions
The review is honest about gaps. More data is needed on:
- Optimal dosing (varies significantly by individual)
- Long-term safety (most trials are 4-10 weeks; we need year-long data)
- Which delivery route is best (oral NMN/NR vs. IV NAD+)
- Whether tissue-level NAD+ actually increases with oral supplementation
NMN vs. NR: The 2026 State of Play
Both NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are NAD+ precursors — molecules your body converts into NAD+. The debate about which is superior has been ongoing for years.
| Factor | NMN | NR |
|---|---|---|
| Human trials | Multiple (250-1,250mg) | Multiple (300-2,000mg) |
| Blood NAD+ elevation | Confirmed dose-dependent | Confirmed dose-dependent |
| Brain penetration (emerging) | Slightly better evidence | Less studied |
| Stability | Less stable (requires cool storage) | More stable |
| FDA status | Still being reviewed for Rx exclusion | Generally recognized dietary supplement |
| Cost | $30-80/month (500mg) | $30-60/month (300mg) |
| Safety profile | No severe adverse events up to 1,250mg | No severe adverse events up to 2,000mg |
2026 practical guidance: Both work. NMN shows slightly more promising neurological data (relevant for Alzheimer's/Parkinson's protection). NR has more extensive long-term data. Either is reasonable to take while waiting for more definitive trial results.
High-dose NMN depletes methyl groups as your body converts it. This can affect DNA methylation patterns, mood, and gene expression. Always pair NMN supplementation with 500mg/day of TMG (betaine). Cost: ~$10/month. This is a critical safety point that most supplement articles miss.
The 2026 Longevity Stack: What the Evidence Actually Supports
Here's how to think about NAD+ supplementation within the broader evidence base:
| Tier | Intervention | Evidence Grade | Notes |
|---|---|---|---|
| Foundation | Exercise (resistance + cardio) | A+ | Raises NAD+ naturally. Non-negotiable. |
| Foundation | Sleep 7-8h/night | A | NAD+ recycling happens during sleep |
| Foundation | Urolithin A 500mg/day | A | Mitophagy, cognitive aging prevention (Nature 2026) |
| Augmentation | NMN 500mg/day + TMG 500mg | B+ | Nature Aging reviewed; safe, measurable effect |
| Augmentation | Caloric restriction 10-15% | A | mTOR inhibition, NAD+ efficiency |
| Medical only | SGLT2i (with doctor) | A | RCT: telomere elongation. Not OTC. |
| Avoid for now | Rapamycin | Mixed | Bryan Johnson dropped March 2026. Side effects. |
Dosing Protocol: The Evidence-Based Starting Point
Based on the clinical trial data summarized in the Nature Aging review:
Conservative Start (250-500mg NMN/day)
- NMN: 250-500mg in the morning (with breakfast)
- TMG: 500mg with NMN
- Duration: 8-12 weeks minimum to assess
- Monitor: Energy levels, cognitive clarity, exercise performance
What NOT to Do
- Don't take NMN at night (it's energizing, may disrupt sleep)
- Don't skip TMG — methyl donor depletion is a real risk at higher doses
- Don't combine high-dose NMN with high-dose NAD IV on the same day
- Don't take rapamycin without medical supervision (and reconsider given Bryan Johnson's March 2026 drop)
Who Should Seriously Consider NAD+ Supplementation
Based on the evidence, NAD+ precursors are most likely to benefit:
- Adults 40+ — This is when NAD+ decline accelerates most meaningfully
- People with family history of Alzheimer's/Parkinson's — The Nature Aging data makes this particularly compelling for prevention
- Athletes/high-output professionals — NAD+ supports mitochondrial efficiency; energy and recovery are commonly reported benefits
- People under high cognitive load — Consistent with the memory/cognition data
Who should wait for more evidence: people under 35, those with cancer (NAD+ may theoretically support cancer cell metabolism — consult oncologist), anyone on medications with NAD+ pathway interactions.
AI-Powered Longevity Protocols
This is where we come in. At ABC AI Lab, we've built an AI-powered longevity protocol generator that takes your age, health goals, biomarkers, and risk tolerance — and builds a personalized, tiered protocol based on the current evidence (including this Nature Aging data).
It's not a generic "take these 10 supplements" list. It's:
- Evidence-graded recommendations (A/B/C tier)
- Interactions checking (like the NMN + TMG pairing above)
- Updated monthly with new research
- Priced at $29 one-time — less than a month of NMN
🧬 Get Your AI Longevity Protocol
Built on current evidence including the 2026 Nature Aging review. Personalized to your age, goals, and budget. Includes NMN/NR dosing, interactions, and safety warnings.
Generate My Protocol →What's Coming Next in NAD+ Research
Clinical trials are actively recruiting (2026-2027):
- MADRINAS trial (Norway) — NMN vs. placebo in MCI patients, 24-week, primary endpoint cognitive tests
- TRITON trial — NR in early Parkinson's, 52-week, examining mitochondrial function
- SLAM trial — Metabolic benefits in metabolic syndrome, 1,000mg NMN vs. placebo
Results expected 2026-2027. If positive, NAD+ precursors could become standard care recommendations — not just biohacker supplements.
Disclaimer: This content is for educational purposes only. Nothing here constitutes medical advice. Consult your physician before starting any supplementation protocol, particularly if you have existing health conditions or take medications.