The science and industry of extending healthy human lifespan. The hallmarks of aging, the contemporary intervention candidates, the longevity-economy companies, and the empirical evidence on what actually works.
The technical and clinical effort to slow, halt, or reverse biological aging — distinct from treating individual age-related diseases.
The conceptual shift, articulated by Aubrey de Grey in the 1990s and now mainstream, is that aging itself is the upstream cause of most chronic disease. Treating cancer, Alzheimer's, cardiovascular disease, and diabetes one at a time has produced incremental gains in lifespan but minimal gains in healthspan — the years lived without major disability. Targeting aging mechanisms directly might compress morbidity into a shorter end-of-life period.
The field is young. Modern molecular gerontology dates from roughly 1993 (Kenyon's daf-2 paper showing single-gene mutations doubling C. elegans lifespan). Most of the contemporary excitement is post-2013 (the Hallmarks of Aging framework). Most of the contemporary commercial activity is post-2018.
Average US life expectancy at birth in 2024: ~76 years (down from 78.8 in 2019, partly COVID-related, partly chronic-disease drift). The maximum recorded human lifespan: Jeanne Calment, 122 years (1875–1997). The empirical maximum has been roughly stable across decades — the curve is rectangularising (more people reaching old age) without the right tail extending much.
Healthspan — years lived without major chronic disease — is what most longevity research targets. The US healthspan-lifespan gap is currently about 9 years; people spend roughly the last decade of life in significant disability.
Heritability of lifespan: about 25%, with most of the heritable component coming from extreme-old-age genetics. Most variation is environmental and behavioural — diet, exercise, smoking, education, social connection, healthcare access.
The López-Otín, Blasco, Partridge, Serrano, Kroemer 2013 paper "The Hallmarks of Aging" gave the field its organising framework. Originally nine hallmarks; revised to twelve in 2023.
The original nine: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication.
The 2023 update added: disabled macroautophagy, chronic inflammation, dysbiosis (microbiome disruption).
The framework's structural value: each hallmark is a candidate intervention target. Most contemporary longevity research focuses on one or more hallmarks. Whether they are independent processes or reflections of a deeper unified mechanism is unsettled.
The longest-studied intervention. Reducing caloric intake by 20–40% (without malnutrition) extends lifespan in yeast, worms, flies, and rodents — typically by 30–50% in lab strains, less in genetically diverse populations.
The 2009 Wisconsin and NIA primate studies on rhesus monkeys produced contradictory results (Wisconsin showed lifespan extension; NIA, less). The combined 2017 reanalysis suggested benefits depend on baseline diet quality and timing.
CALERIE-2 (2007–2012) — the first randomised CR trial in non-obese humans. Modest CR (12% reduction over 2 years) showed favourable cardiometabolic markers but not yet definitive lifespan effects.
Intermittent fasting / time-restricted eating: easier to maintain than continuous CR; some animal evidence of benefit; human evidence less clear than the popular literature suggests. Krista Varady's research and Mark Mattson's NEJM review (2019) are the major sources.
Rapamycin (sirolimus) is the most-studied geroprotective drug candidate. Originally developed as an immunosuppressant for organ transplantation. The 2009 NIA Interventions Testing Program showed rapamycin extended median lifespan in mice by 9–14% — the first drug intervention to do so in mammals.
Mechanism: inhibition of mTOR (mechanistic target of rapamycin), the cellular nutrient-sensing complex. mTOR inhibition mimics aspects of caloric restriction.
Human use is off-label and contested. Matt Kaeberlein at the University of Washington runs the Dog Aging Project (rapamycin trial in domestic dogs). Anecdotal use among the longevity-research community is widespread but not formally tested at low intermittent doses.
Side effects at organ-transplant doses are substantial (immunosuppression, glucose intolerance). The longevity hypothesis is that lower intermittent doses might capture benefit without significant side effects. Properly powered human trials are still missing.
Senescent cells — cells that have stopped dividing but resist apoptosis and secrete inflammatory factors (the senescence-associated secretory phenotype, SASP) — accumulate with age and contribute to multiple chronic diseases.
Senolytics are drugs that selectively kill senescent cells. The pioneering work: James Kirkland at Mayo Clinic with the dasatinib + quercetin combination (2015) — showed lifespan extension in mice. Subsequent agents: navitoclax, fisetin (a flavonoid in fruits), UBX0101 (Unity Biotechnology, failed phase II for osteoarthritis 2020).
The 2024 picture: human trials are early-stage. Fisetin trials at the University of Minnesota and Mayo are ongoing for diabetic kidney disease, osteoarthritis, and frailty. Effects are modest where found.
The longevity-medicine question is whether one-time or intermittent senolytic dosing can produce durable health benefits. Most agents have specificity issues — they kill senescent cells but also some healthy ones. The risk-benefit at population scale remains uncertain.
Nicotinamide adenine dinucleotide (NAD+) levels decline with age. NAD+ is a substrate for sirtuins (a family of regulatory proteins) and PARPs (DNA-repair proteins). The hypothesis: restoring NAD+ levels improves cellular function in aged tissues.
NAD+ precursors — nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) — are the major intervention candidates. Both are sold as supplements; both have produced positive cellular biomarker effects in human trials. Whether the cellular biomarker improvements translate to clinical health benefits is unclear.
David Sinclair's lab at Harvard popularised the NAD+ pathway through Lifespan (2019) and significant commercial advocacy. The mechanistic claims have generated substantial controversy in academic gerontology — Charles Brenner has been a prominent critic.
The current empirical state: NAD+ precursor supplementation is safe at typical doses; modest cellular effects are real; clinical benefits remain unproven; the supplement industry has substantially outrun the science.
Metformin is a 60-year-old type-2 diabetes drug. Multiple observational studies have suggested diabetics on metformin have lower all-cause mortality than non-diabetics — an unusual finding that prompted geroprotective interest.
The proposed TAME trial (Targeting Aging with Metformin) — led by Nir Barzilai at Albert Einstein — would be the first major US trial designed to test aging-as-target. The trial has been seeking FDA approval and funding since 2015. As of 2026, partial funding has been secured but the trial has not yet enrolled patients at full scale.
The 2017 Glint study (large UK cohort) confirmed metformin's mortality benefit even in non-diabetics. Mechanisms include AMPK activation, mTOR inhibition, and effects on the gut microbiome.
Off-label use among the longevity-medicine community is substantial; the empirical case is real but the sample sizes for non-diabetic populations remain small.
The Horvath clock (2013) showed that DNA methylation patterns at specific CpG sites predict chronological age within 3–4 years across human tissues. Subsequent clocks — Hannum (2013), GrimAge (2019), DunedinPACE (2022) — improved prediction and added health-outcome correlations.
The clinical promise: measure biological age, intervene, re-measure, see if biological age slowed or reversed. The TruDiagnostic, Elysium Health, and Tally Health consumer products offer clock-based testing.
The technical caveat: the clocks were trained on chronological age; whether shifts produced by interventions reflect actual aging biology or just methylation marker changes is contested. Steve Horvath has emphasised the second-generation clocks (GrimAge, DunedinPACE) trained on health outcomes are more clinically meaningful.
For trial design, epigenetic clocks have become a near-universal endpoint. Whether they can replace mortality endpoints in regulatory contexts remains an open question.
Shinya Yamanaka's 2006 paper showed that four transcription factors (Oct4, Sox2, Klf4, c-Myc) could reprogram adult cells back to a stem-cell-like state. The Nobel followed in 2012.
The longevity application: partial reprogramming. Brief exposure to reprogramming factors might reset cellular age without fully dedifferentiating cells. The 2016 Belmonte paper showed in vivo partial reprogramming extended lifespan in progeroid mice.
Altos Labs (founded 2022 with $3 billion in initial funding from Bezos and others; recruited Belmonte, Steve Horvath, and other senior researchers) is the major commercial bet on cellular reprogramming as longevity therapy.
The technical question: can partial reprogramming be controlled tightly enough to reset age without inducing tumorigenesis? Pluripotent stem cells form teratomas; the reprogramming process must be stopped before that point. The therapeutic window is narrow.
2026 status: animal proof-of-concept robust; safe human delivery still distant.
Surgically connecting circulatory systems of young and old mice (parabiosis) restores some aging hallmarks in older animals. The 1956 McCay studies first showed this; the 2005 Conboy lab work and subsequent Saul Villeda research at UCSF identified specific pro-youth and pro-aging factors.
Specific candidate factors: GDF11 (proposed rejuvenating factor; the empirical case is contested — opposing labs have published positive and negative findings); oxytocin; plasma proteome differences between young and old.
Ambrosia Health (2016–2019) sold young-donor plasma transfusions for aging at $8,000 per treatment; FDA warned against the practice in 2019 and the company closed.
The serious version of this research: identifying specific factors in young plasma that produce rejuvenation, then synthesising or producing them as drugs. Active areas: blood-derived exosomes, specific growth factors, plasma fractionation. Multiple academic labs and companies (Alkahest, since acquired) are working in this space.
Telomeres are the protective end-caps of chromosomes. They shorten with each cell division. When too short, cells senesce or die. Elizabeth Blackburn, Carol Greider, and Jack Szostak won the 2009 Nobel for the underlying discoveries.
Telomerase — the enzyme that lengthens telomeres — is highly active in stem cells, germ cells, and most cancers; suppressed in most adult somatic cells. The longevity aspiration: activate telomerase therapeutically to extend cellular replicative capacity without inducing cancer.
Maria Blasco's lab in Madrid has shown telomerase gene therapy extends lifespan in mice. BioViva (2015) — Liz Parrish controversially self-administered telomerase gene therapy. Bioethics community broadly considered the act premature.
The cancer concern is real. About 90% of human cancers express telomerase. Telomerase activation must be precisely targeted to avoid tumour promotion. Current clinical translation is cautious; therapeutic telomerase activation is not yet a proven safe human intervention.
The empirically best-supported longevity interventions are the unglamorous ones.
Exercise. The most robust geroprotective intervention available. Cardiorespiratory fitness predicts mortality more strongly than smoking, diabetes, hypertension, or hyperlipidaemia (Mandsager et al. 2018). Recommendation: 150+ minutes/week of moderate-intensity aerobic activity plus 2 sessions of resistance training.
Sleep. Sleep duration of 7–9 hours and consistent timing. Chronic insufficient sleep is associated with elevated dementia risk, cardiovascular disease, and all-cause mortality (Walker, Why We Sleep; the specific dose-response curves are debated).
Diet. Mediterranean dietary pattern has the strongest causal evidence (PREDIMED trial, 2013). Avoid ultra-processed foods. Plant-forward but not necessarily vegan. Moderate alcohol benefit claims have largely collapsed (Mendelian randomisation, 2023).
Social connection. Loneliness and social isolation are major mortality risk factors (Holt-Lunstad meta-analyses). Effect sizes comparable to smoking.
Smoking cessation. Single largest preventable cause of premature mortality.
Peter Attia (physician, podcast host) has popularised an aggressive preventive-medicine framework he calls Medicine 3.0. Outlive (2023) is the central text.
The framework's components: early detection (CT colonoscopy, advanced imaging), tight metabolic control (CGM use; ApoB lowering as a primary cardiovascular target), "the four horsemen" framing (cardiovascular disease, cancer, neurodegenerative disease, type 2 diabetes — the disease categories that account for most premature death), and aggressive intervention before disease becomes clinical.
The empirical merits: aggressive ApoB lowering has strong cardiovascular evidence; resistance training and protein adequacy have strong sarcopenia-prevention evidence; cancer screening at younger ages remains controversial.
The criticisms: most of the protocol is unaffordable; some interventions (advanced imaging, frequent labs) lack population-scale benefit evidence; the practice tends toward over-screening for some patients.
The intersection with longevity science: Attia is more conservative than the longevity-bio community. He emphasises proven preventive interventions over experimental geroprotection.
Bryan Johnson, founder of Braintree (sold to PayPal for $800M in 2013), has spent ~$2M/year since 2021 on his "Project Blueprint" longevity protocol — an aggressive multi-intervention experimental regimen with public data sharing. He calls the project "Don't Die."
The protocol involves ~100 supplements and pharmaceuticals daily, dozens of biomarkers tracked monthly, plasma exchanges with his teenage son (briefly, before discontinued), and participation in multiple experimental therapies.
The scientific opinion is divided. Johnson's biomarkers have improved substantially across many measures (epigenetic age, cardiovascular fitness, metabolic markers). Whether the gains are due to specific interventions or to extreme dedication to general health is unclear. The protocol is unreplicable for almost everyone.
The cultural significance: Johnson has demonstrated that aggressive personal investment in longevity is now possible at the individual level. The model — quantified-self extremism plus public data — has inspired a community. The medical establishment remains skeptical of single-person n=1 experiments as evidence for population intervention.
The 2018–2024 period saw the emergence of a longevity industry. Major companies:
Altos Labs (founded 2022, $3B initial; cellular reprogramming). Calico Labs (Google/Alphabet, founded 2013, ~$2B in research; broad geroscience). Retro Biosciences (founded 2021, OpenAI's Sam Altman invested; partial reprogramming, autophagy). NewLimit (founded 2021, Brian Armstrong from Coinbase; epigenetic reprogramming). Loyal (canine longevity drug development; LOY-001 received FDA conditional approval 2025 for large-breed dogs). Insilico Medicine (AI-driven drug discovery for aging-related disease).
BioAge Labs, Unity Biotechnology, Resilience Bio, Life Biosciences, Juvenescence, Hevolution Foundation (Saudi-backed, $1B/year in longevity research grants from 2022).
The 2024–2025 funding climate has cooled compared to 2021's peak but remains substantial. The structural question — whether the industry will produce approved therapies that meaningfully extend healthspan, or whether the work will primarily yield treatments for specific age-related diseases — is still being decided.
Hevolution Foundation (Riyadh, founded 2021) — Saudi Arabian-funded longevity research foundation. Pledges $1 billion per year through 2031 in grants. Has become a major non-NIH funder of geroscience research, particularly for early-career investigators and projects too speculative for traditional grants.
XPRIZE Healthspan — $101M competition launched 2023, sponsored by Hevolution and others. Goal: a single intervention that demonstrably reverses 10 years of biological age in adults aged 65+. Trials must demonstrate function (cognitive, immune, physical) restoration. The judging criteria favour rigorous trial design over single-biomarker results.
The shift is structural. The 2010s longevity research was largely venture-funded (which favours commercial speed) or NIH-funded (which favours conservative endpoints). Hevolution and XPRIZE represent a third channel: large-scale prize and grant funding willing to take the field seriously without the constraints of the standard models.
Cryonics — preservation of legally-dead bodies at -196°C in liquid nitrogen, with the hope of future revival. Two main organizations: Alcor Life Extension Foundation (Arizona, founded 1972; ~1,800 members, ~200 patients in cryostasis) and Cryonics Institute (Michigan, founded 1976).
The procedure: at legal death, vitrification chemicals replace blood; body is cooled to liquid-nitrogen temperatures; long-term storage. Membership costs ~$200K (whole-body) or ~$80K (neuro-only). Both organisations operate as nonprofits.
The scientific case is uncertain. Vitrification of small organ samples works (corneas, tissue biopsies). Whole-body vitrification at temperatures that preserve neuronal microstructure has not been demonstrated; cracking and freezing damage at the macroscopic scale are routine.
The philosophical position: even modest probability of future revival, combined with very long potential time horizon, may make the bet rational under certain assumptions. The empirical position: nobody has been revived. Most mainstream gerontology remains skeptical; the field has occupied a marginal position in serious longevity science.
The hypothesis: human cognitive identity could in principle be transferred to a non-biological substrate, achieving a form of immortality independent of biological aging.
The technical requirements: a sufficiently detailed brain scan; a computational substrate capable of running the resulting model; a process for transferring identity that preserves continuity of consciousness.
None of these is currently solved. Whole-brain emulation (Sandberg & Bostrom, 2008 Oxford report) outlined what would be required: nanometer-scale connectomic mapping, simultaneous capture of synaptic states, computational requirements likely beyond current hardware. Connectome projects have so far mapped C. elegans (302 neurons, 1986), Drosophila larva, partial mouse brain. The first mammalian whole-brain connectome (a mouse) is expected in the late 2020s.
The philosophical questions — whether a copy is "you," whether continuity matters — remain unresolved. The position has substantial advocacy in the rationalist and transhumanist communities; mainstream cognitive science treats it as speculation.
The dietary-supplement industry has aggressively marketed longevity-related products. Most lack rigorous human evidence. The most-discussed:
NMN / NR (NAD+ precursors) — modest cellular evidence; clinical benefits unproven.
Resveratrol — sirtuin-activator hypothesis; the David Sinclair-promoted molecule; clinical benefits in humans largely unsupported by current evidence (the 2023 meta-analyses have been negative).
Spermidine — autophagy inducer; modest observational support; intervention trials small.
Fisetin — senolytic candidate; promising animal data; human trials ongoing.
Berberine — metformin-like glucose-lowering effects; broader claims undertested.
Omega-3s, vitamin D, magnesium — established cardiovascular and metabolic roles; longevity-specific claims often overstated relative to evidence.
The honest summary: outside of correcting deficiencies, supplement-based longevity interventions have minimal rigorous human evidence as of 2026. The supplement industry's marketing has substantially exceeded the science.
The longevity-medicine practice now includes a routine battery of diagnostic measurements. The major categories:
Cardiovascular: ApoB, lipoprotein(a), high-sensitivity C-reactive protein, coronary CT angiography or calcium score, advanced lipid panel.
Metabolic: continuous glucose monitor (Dexcom, Levels), HOMA-IR, fasting insulin.
Body composition: DEXA scans for bone density and lean-mass estimation; whole-body MRI (Prenuvo, Ezra) for early cancer screening — controversial; the case for routine asymptomatic MRI is weak.
Functional: VO2 max measurement, grip strength, gait speed, reaction time. Functional measures predict mortality more reliably than most molecular ones.
Biological-age clocks: epigenetic clock (TruDiagnostic), proteomic-age clocks, glycan-age.
The clinical question is which of these provide actionable information vs which produce expensive false-positive findings. The evidence base is uneven.
The longest-running gerontology data come from centenarians and supercentenarians. Major studies: New England Centenarian Study (Tom Perls, since 1995), Long Life Family Study (NIH), Ashkenazi Jewish Longevity Genes Project (Nir Barzilai), Okinawa Centenarian Study.
The findings: most centenarians have unusual genetic profiles (FOXO3, APOE2, particular mitochondrial haplotypes). They have not, in general, lived particularly clean lives — many smoked, many drank, many were overweight at points. What they share is delayed disease onset rather than disease avoidance.
The "Blue Zones" (Loma Linda CA, Sardinia, Okinawa, Nicoya in Costa Rica, Ikaria in Greece) — popularised by Dan Buettner since 2008 — claim cluster effects. Saul Justin Newman's 2024 paper raised serious questions about the underlying data quality (uneven birth-record reliability across these regions; some apparent "long-lived" populations may reflect record-keeping artefacts rather than actual age).
The cautious takeaway: extreme longevity is partly genetic, partly lifestyle, partly luck, and partly measurement error.
Longevity technology, if it works, will be expensive at first. The current longevity-medicine practices ($30–80K/year in some clinics) are accessible only to the wealthy. The risk is amplification of an already-substantial life-expectancy gap by socioeconomic status — currently ~10 years between top and bottom income deciles in the US.
The ethical positions:
Permissive: longevity technology, like other medical technology, will start expensive and become accessible. Trickle-down is the standard pattern.
Restrictive: longevity gains threaten intergenerational fairness and pension/social-security systems. The default should be skepticism until population-scale benefits are demonstrated.
Egalitarian: longevity research should prioritise interventions deliverable at population scale (vaccines, lifestyle medicine) over high-cost individual interventions.
The political-economy question is largely unaddressed in the field. Most longevity research is privately funded; the access trajectory is determined more by venture-capital incentives than by deliberate policy.
Reasonable predictions for 2030:
1. At least one geroprotective drug will reach FDA approval, almost certainly for a specific age-related disease (frailty, sarcopenia, age-related macular degeneration) rather than aging itself. Senolytics or senomorphics are the leading candidates.
2. Epigenetic clocks will become routine in clinical research as endpoints, though probably not yet as regulatory endpoints.
3. The TAME trial or its successor will report results, providing the strongest evidence yet on aging-as-target trial design.
4. Cellular reprogramming therapies will likely have human trials running but unlikely to have approvals.
5. The longevity-medicine practice will mature toward more standardised protocols. The Bryan Johnson-style extreme experimentation will continue but will not be the mainstream path.
What's unlikely by 2030: substantial extension of healthy lifespan from a single intervention; reversal of aging in any meaningful sense; cryonics revival; mind uploading. The bigger gains will come from better preventive medicine and incremental treatments, not from a "longevity drug."
↑ David Sinclair · The science behind why we age
Watch · Peter Attia · What is longevity?
Watch · Hallmarks of aging · López-Otín lecture
The strongest-evidence longevity moves available to most people in 2026:
1. Build cardiorespiratory fitness. Get to a VO2 max in the top quartile for your age. The single largest modifiable mortality risk factor.
2. Build muscle. Resistance training 2–3 sessions per week. Sarcopenia is the slow killer most people ignore until it becomes irreversible.
3. Sleep 7–9 hours consistently. Treat sleep as the most important biological intervention you control daily.
4. Mediterranean-pattern diet; minimise ultra-processed foods; sufficient protein (1.2–1.6 g/kg body weight for adults over 40).
5. Don't smoke. Reduce alcohol substantially; the recent cancer-risk evidence has eliminated previous "moderate-drinking benefit" claims.
6. Maintain social connection. Cultivate close relationships actively. Loneliness is a major mortality factor.
7. Cardiovascular risk monitoring. Know your ApoB, blood pressure, fasting glucose. Treat early and aggressively if elevated.
8. Don't waste money on most supplements. Vitamin D if deficient; omega-3s if low fish intake; B12 if vegetarian. Most other supplements lack rigorous evidence.
Longevity technology in 2026 is a scientific field with a real research base, a venture-funded industry, a celebrity-medicine layer, and a much larger commercial supplement industry making claims well beyond the evidence.
The genuine science is real and exciting. The hallmarks framework has organised the field. Senolytics, partial reprogramming, NAD+ biology, and epigenetic clocks are productive research areas with plausible therapeutic potential. Multiple companies have legitimate technology platforms.
The honest near-term expectation: the next decade will produce specific drugs for specific age-related conditions, modest healthspan improvements through better preventive medicine, and gradual integration of biological-age measurement into routine care. It is unlikely to produce a single dramatic intervention that adds many years of healthy life.
The honest long-term expectation: aging biology is genuinely tractable in ways the field has only begun to demonstrate. By 2050, the medicine of aging will look meaningfully different from what we have now. By 2100, possibly very different. The path between is mostly unglamorous incremental work.
Longevity Technology — Volume X, Deck 12 of The Deck Catalog. Set in IBM Plex Sans and Tiempos Text. Off-white #f4f0e8; teal, coral, and gold accents.
Twenty-eight leaves on the science of extending healthy life. The field is real. The marketing has outrun it.
↑ Vol. X · Future · Deck 12