Key people, competing theories, ranked interventions, and the honest evidence base for extending human healthspan and lifespan.
The longevity field sits at a remarkable inflection point. Billions of dollars are flowing into aging research from Altos Labs ($3B+), Retro Biosciences, and Hevolution Foundation. Epigenetic clocks can now estimate your biological age from a blood sample. GLP-1 agonists may be the first unintentional longevity drugs. And yet the single most powerful intervention remains what it has always been: regular exercise. The gap between exciting mouse data and proven human benefit remains enormous for almost everything else.
This index maps the landscape — the theories, the interventions, the key figures, and the honest state of the evidence. It is designed for a reader who wants to understand both the science and the sociology of a field where Nobel laureates, biohackers, venture capitalists, and wellness influencers all compete to define what "anti-aging" means.
Every claim has been reviewed for accuracy and bias. Where evidence is contested, we say so. Where we found errors in our original research, we corrected them. Confidence levels are shown throughout. Note that this content was AI-generated and has been primarily AI fact-checked, not personally verified by the author.
The boring stuff works best. Exercise, sleep, not smoking, metabolic health, and social connection have the strongest evidence by far.What Actually Works — Research Finding
Why do we age? Nine competing frameworks, from evolutionary logic to molecular mechanisms. Modern geroscience increasingly views them as interconnected.
12 hallmarks organized as primary, antagonistic, and integrative. The dominant organizing framework. Updated from 9 to 12 hallmarks in 2023, adding dysbiosis, disabled macroautophagy, and chronic inflammation.
MainstreamAging as accumulation of 7 types of molecular damage. An engineering approach: periodically repair damage rather than slow its creation. Influential but the SENS framework has produced limited translational results to date.
Influential / ContestedAging as progressive loss of epigenetic information. DNA is intact but cell readout degrades. The ICE mouse model (Cell 2023) was published then corrected. Charles Brenner called it "not even wrong." Controversial within the field.
ContestedAging driven by continued growth-promoting programs (especially mTOR) that were beneficial in youth. Rapamycin's consistent lifespan extension across species is the strongest validation. Rising influence in the field.
Rising InfluenceGenes enhancing fitness early in life have deleterious effects later. The foundational evolutionary "why" of aging. Explains why aging exists but not its mechanisms. Supported by examples like IGF-1 and testosterone.
MainstreamChronic, sterile, low-grade inflammation increases with age and drives disease. Driven by senescent cell SASP, gut dysbiosis, and accumulated damage. Elevated to its own hallmark in the 2023 update.
MainstreamDNA methylation changes systematically with age. Clocks predict mortality, but whether drift is cause or consequence remains debated. The most measurable aspect of aging, but mechanism unclear.
EmergingOriginally: free radicals cause aging. Antioxidant trials failed. The original theory is largely falsified, but a nuanced version (mitochondrial signaling dysfunction) survives. A cautionary tale about supplement hype.
RevisedSomatic mutations accumulate inescapably. Cross-species mutation rates inversely correlate with lifespan. Vijg argues this imposes a hard ceiling (~115 years). CHIP links mutations to cardiovascular and cancer risk.
MainstreamThe synthesis: Modern geroscience rejects the programmed-vs-damage dichotomy. The field converges on an integrated network view where hallmarks interact bidirectionally. No single theory captures the whole picture.
25 interventions evaluated by evidence quality. Rigorous honesty: distinguishing "exciting mouse result" from "replicated human RCT."
| # | Intervention | Evidence | Effect Size | Rating | Confidence |
|---|---|---|---|---|---|
| 1 | Exercise (all types) | Multiple RCTs, mega-cohorts | 30-40% mortality reduction | High | |
| 2 | Not Smoking | Massive epidemiological | +10 years life expectancy | High | |
| 3 | Sleep Optimization (7-8h) | Large prospective cohorts | 14-34% mortality risk from imbalanced | High | |
| 4 | Dietary Patterns (Mediterranean) | RCTs + large cohorts | 8-25% mortality reduction | High | |
| 5 | Social Connection | 148 studies (Holt-Lunstad) | OR 1.50 survival (95% CI 1.42-1.59) | High | |
| 6 | No/Moderate Alcohol | Large meta-analyses | Up to 10 years if quitting heavy use | High | |
| 7 | Caloric Restriction / IF / TRE | 1 RCT (CALERIE) + animal | 2-3% slowed aging pace (DunedinPACE) | Medium | |
| 8 | Rapamycin / Rapalogs | ITP (mice) + PEARL trial | 14-26% lifespan in mice; safe in humans | Medium | |
| 9 | GLP-1 Agonists (semaglutide) | Large RCTs (SELECT) | 20% MACE; HR 0.81 mortality (CI 0.71-0.93) | Corrected | |
| 10 | Metformin | Observational + diabetic RCTs | Modest; TAME trial underfunded | Medium | |
| 11 | Omega-3 Fatty Acids | RCTs (HR 0.92, CI 0.85-0.99) | 8% CV mortality reduction | Medium | |
| 12 | Vitamin D (if deficient) | RCTs + observational | 16% cancer mortality reduction | Medium | |
| 13 | Acarbose | ITP (mice) | ~10% lifespan in males | Low | |
| 14 | Canagliflozin (SGLT2i) | ITP (mice) + CV RCTs | 14% lifespan in male mice | Low | |
| 15 | Spermidine | Observational + animal | Epidemiological association | Low | |
| 16 | NAD+ Precursors (NMN/NR) | Small RCTs | Raises NAD+; clinical benefits unclear | Low | |
| 17 | Senolytics (D+Q, fisetin) | Phase I/II trials | Safe; efficacy unproven in humans | Low | |
| 18 | Epigenetic Reprogramming (OSK) | Animal studies | 109% remaining lifespan in old mice* | Low | |
| 19 | Resveratrol | Failed pharma program | No consistent benefit | High (debunked) | |
| 20 | Young Plasma / Parabiosis | Animal + tiny pilots | No human evidence of benefit | Low |
Strong = Replicated human evidence · Promising = Some human data · Early = Primarily animal · Speculative = Animal/in-vitro only · Debunked = Failed/contradicted
*OSK 109% is extension of remaining lifespan in 124-week-old mice (Macip et al., Cellular Reprogramming 2024), not total lifespan. These mice were equivalent to ~77 human years.
An honest assessment for a person today. Four tiers from "do this immediately" to "don't waste your money."
30-40% all-cause mortality reduction (BJSM 2025). CRF is the single strongest predictor of mortality. Each 1-MET increase = 13-15% mortality reduction. Zone 2 cardio (150-180+ min/week), resistance training (2-3x/week), VO2max intervals (1-2x/week). Peter Attia's "Centenarian Decathlon": train for what you want to do at 90.
Short sleep (<7h) increases mortality 14%; long sleep (>9h) increases it 34%. Sleep regularity may matter more than duration. Cool room (65-68°F), complete darkness, morning light exposure, no caffeine after noon.
Quitting smoking adds ~10 years of life expectancy. WHO position: no safe level of alcohol. The "J-curve" for moderate drinking was an artifact of sick-quitter bias (JAMA Network Open meta-analysis, 2023).
Key metrics: waist circumference, HbA1c (<5.7%), fasting insulin, blood pressure (<120/80), ApoB (best single lipid metric). Each 10 mg/dL ApoB decrease = ~9% heart disease risk reduction. Annual bloodwork is cheap insurance.
OR 1.50 survival for strong social ties (95% CI 1.42-1.59, Holt-Lunstad 2010). Mortality risk from isolation equivalent to smoking 15 cigarettes/day. The most underrated longevity intervention.
14-26% lifespan extension in mice (ITP). PEARL trial (n=114): safe at low doses, but compounded rapamycin was ~3.5x less bioavailable than expected. Growing off-label community. Human longevity evidence remains thin despite strong animal data.
Cheap ($50/year), safe, widely used. Diabetics on metformin may outlive non-diabetic controls (observational). TAME trial chronically underfunded despite importance; ARPA-H now involved. May blunt exercise adaptations.
CALERIE RCT: 2-3% slowed aging pace (DunedinPACE) with 12% CR. Extends lifespan 10-30% in mice. TRE (16:8) is more sustainable. No direct evidence fasting extends human lifespan; benefits limited to surrogate endpoints.
SELECT trial: 20% MACE reduction, HR 0.81 all-cause mortality (CI 0.71-0.93) in obese non-diabetics. Strong for those with obesity/metabolic dysfunction. For lean, healthy individuals: entirely speculative. Muscle loss concern for aging populations.
Omega-3 (HR 0.92 CV death, CI 0.85-0.99), vitamin D (if deficient: 16% cancer mortality reduction), magnesium, creatine (muscle + cognitive). Most other supplements are a waste of money.
Compelling mouse data. Unity Biotechnology dissolved after clinical failures. D+Q in Phase I/II — safe but efficacy unproven. The most exciting mechanistic target, but years from knowing if it works in humans.
Raises NAD+ reliably. Clinical benefits elusive despite strong mouse data. The supplement industry has far outpaced the science. Sinclair takes 1g NMN daily; Kaeberlein and Brenner are skeptical.
Induces autophagy. Epidemiological association with reduced mortality. Available in wheat germ. Eating spermidine-rich foods is free and likely harmless; supplementation is speculative.
Debunked. The sirtuin-activation assay was an artifact. GSK paid $720M for Sirtris (2008) and shut it down. 2024 systematic review: "no conclusive clinical evidence" in any healthcare setting.
Conboy lab: dilution of old blood may matter more than adding young factors. Ambrosia received FDA warning. Bryan Johnson's plasma exchange with his son showed no benefit.
TA-65 lacks evidence. Stem cell clinics carry real risks (infection, tumors). Red light panels, hyperbaric oxygen, peptide stacks — marketing ahead of evidence. Do not confuse consumer enthusiasm for science.
The equity problem: The most effective interventions (exercise, sleep, not smoking) are free. The most speculative ones cost thousands per year. The longevity field risks becoming a luxury market. A society serious about longevity would invest in making healthcare, nutrition, and safe exercise accessible to everyone.
The key fault lines that shape regulation, funding, and what millions put in their bodies.
Should aging be classified as a treatable medical condition? Without disease status, the FDA cannot approve drugs "for aging."
De Grey, Sinclair, Zhavoronkov. Aging causes disease, therefore aging is the root disease. Classification would unlock drug pipelines and insurance coverage.
Hayflick, Olshansky, Ramakrishnan. Aging is a fundamental biological process. Medicalizing everyone over 60 reinforces ageism. Disease implies deviation from normal; aging is universal.
A recurring pattern: Sinclair makes exciting claims, media amplifies them, then the scientific community finds problems. Resveratrol (assay artifact, $720M failure), NMN (clinical benefits elusive), ICE paper (correction), Leap Years (dog supplement controversy).
Prolific researcher (200+ papers), popularized NAD+ biology, driving public interest in aging research. Some findings confirmed broadly.
Pattern of commercially-driven hype outpacing evidence. 12+ companies, many failed (OvaScience, CohBar, Sirtris). Brenner: the Information Theory is "not even wrong."
Vijg: ceiling at ~115 based on supercentenarian plateaus. Olshansky (2024 Nature Aging): life expectancy gains decelerating since 1990. Rebuttals: mortality plateau above 105, negligible senescence in some species, de Grey's LEV argument.
De Grey, Barbi. Mortality plateaus suggest no fixed wall. Biotech could break historical patterns.
Vijg, Olshansky, Hayflick. Supercentenarian gains plateaued. Multiple organ systems have concordant limits. Evolution never selected for extreme longevity.
CALERIE showed 2-3% slowed aging pace — real but modest. CR Society members show impressive biomarkers but longevity data is decades away. A Nature 2024 study in genetically diverse mice showed individual genetic variation matters enormously.
$2M+/year protocol, Netflix documentary, $20M first-day product sales. Credits: unprecedented transparency, mainstreaming longevity, Rejuvenation Olympics. Concerns: N=1 conflated with science, gene therapy in Honduras, accessibility gap, "Don't Die" as ideology.
Ezekiel Emanuel ("Why I Hope to Die at 75"): extended old age often means decline, not vitality. Ramakrishnan's "Why We Die" questions whether immortality would satisfy us. Disability rights perspectives, environmental concerns, generational equity. The longevity movement's implicit assumption that death is always bad deserves scrutiny.
The boring truth: Across all these debates, lifestyle fundamentals have a larger evidence base and effect size than any pharmacological or experimental intervention. The exciting research gets the attention; the mundane protocols deliver the results.
How do we know if an anti-aging intervention works? The central challenge of longevity science is measurement.
353 CpG sites from 8,000 samples across 51 tissues. Median error: 3.6 years. Multi-tissue applicability. Trained on chronological age, so limited for health prediction.
Two-step: 9 blood biomarkers predicting mortality, then CpGs predicting the composite. Each 1-year increase = ~9% mortality increase. Free blood-biomarker version available.
The "death clock." DNA methylation surrogates for 12 plasma proteins + smoking. Best mortality predictor of all epigenetic clocks. 81% increased hazard per SD of acceleration.
Measures pace of aging (rate of change), not static age. Trained on 20 years of longitudinal data. Used in the Rejuvenation Olympics. Responds to interventions, making it useful for clinical trials.
Separates CpGs into those causally linked to aging (DamAge) vs. adaptive responses (AdaptAge). Aims to distinguish clocks that measure aging from those measuring the body's response to it.
VO2max: strongest mortality predictor. Grip strength: independent predictor across all ages. ApoB: best single lipid metric. These are cheaper and more actionable than epigenetic testing.
The validation gap: We can measure biological age with increasing precision, but we don't yet know if changing your clock score actually changes your health outcomes. Step 1 (build clocks that predict mortality) is done. Step 2 (prove that interventions changing clock scores also change outcomes) remains the gap.
Who pays for longevity research? An estimated $8.5B flowed into the sector in 2024, but the details reveal important biases.
Of the NIA's ~$4.5B total, roughly $3.5B goes to Alzheimer's. Basic biology of aging gets a fraction — far less than any single disease category.
First major US government program explicitly targeting aging. Funding Buck Institute, Stanford, and Cambrian Bio for 3-year aging trials. Established 2022.
Saudi-backed, largest single commitment to aging research. Actual disbursements ~$200-400M so far. Includes $230M for geroscience, $40M XPRIZE Healthspan.
Largest longevity company ever. Bezos, Milner, ARCH. Epigenetic reprogramming focus. Recruited Nobel laureates. No products yet. Moving toward clinical development (2025).
Sam Altman's personal investment. Raising $1B Series A at $5B valuation. AI+longevity convergence with OpenAI partnership. Three pillars: reprogramming, autophagy, plasma.
11 years, no products. AbbVie partnership dissolved Nov 2025. The cautionary tale of longevity funding. Extreme secrecy, limited output despite enormous spend.
Backed by Bezos, Thiel, ARCH. First senolytic trials failed. Stockholders voted to liquidate Sept 2025. Mouse logic doesn't always translate to humans.
First FDA-approved drug for lifespan extension (dogs). STAY study: 1,300 dogs, 70 clinics. If approved, establishes precedent that "longevity" is an approvable endpoint.
25 important people in longevity science. Scientists, clinicians, entrepreneurs, communicators — and skeptics.