Lifespan, healthspan, and what to aim at

Living longer is only appealing if the additional years are functional. Healthspan — years lived without major disability or disease — is the more useful target, and it is where the modifiable factors have the clearest influence.

Large cohort studies consistently find that people meeting several basic health behaviours live substantially longer, and more of those years are free of major chronic disease. The behaviours are the same ones that appear in every guideline: not smoking, being active, eating well, moderating alcohol, maintaining a healthy weight, and sleeping adequately.

  • Function — strength, balance, cognition, independence — is what determines quality of later life.
  • Risk-factor control compounds over decades, which is why starting earlier matters.
  • It is never too late; benefits from stopping smoking and starting activity appear at every age.

The evidence-backed foundations

These are the interventions with the strongest human evidence. None are proprietary.

  • Do not smoke — the single largest modifiable factor for premature death.
  • Move regularly — 150 to 300 minutes a week of moderate activity plus two strength sessions.
  • Eat a plant-forward pattern — Mediterranean or DASH style, high in fibre, low in ultra-processed food and added sugar.
  • Sleep 7 to 9 hours consistently.
  • Limit alcohol — less is better, and no amount is established as beneficial.
  • Manage blood pressure, blood sugar, and cholesterol — these do more work than most lifestyle tweaks.
  • Stay connected — social isolation is associated with higher mortality.
  • Keep up preventive care — screening, vaccination, and dental care.

Also underrated: seatbelts, helmets, home fall prevention, and firearm safety, which affect life expectancy through injury rather than disease.

Where the evidence is genuinely mixed

Several popular longevity ideas rest on animal data, short-term human markers, or observational patterns that have not been confirmed in outcome trials.

  • Caloric restriction — extends lifespan in several animal species; human trials show improvements in risk markers, with no lifespan data available.
  • Intermittent fasting and time-restricted eating — outcomes broadly similar to conventional calorie reduction; no evidence of a distinct longevity effect.
  • Metformin, rapamycin, NAD precursors, senolytics — active areas of research, currently without evidence of lifespan extension in healthy humans. Some are being formally trialled.
  • Cold plunges, saunas, red light — some plausible short-term physiological effects; sauna use has interesting observational data, but causal evidence is limited.
  • Most supplements — no consistent mortality benefit in people who are not deficient.

Describing these accurately is not scepticism for its own sake — it is what lets you spend effort and money where the return is real.

Biological age tests and tracking

Biological age products — epigenetic clocks, panels combining lab values, various proprietary algorithms — are an active research field. As consumer products they have real limitations: different tests give different answers for the same person, results can shift with day-to-day variation, and none have been validated as tools for guiding individual decisions or demonstrated to improve outcomes.

Standard measurements remain more useful: blood pressure, lipids, A1C, kidney and liver function, weight and waist, plus functional markers such as grip strength, walking speed, and sit-to-stand ability. These are cheap, interpretable, and actionable.

  • Track a small number of things you would actually act on.
  • Prefer trends over single readings.
  • Be cautious with panels sold direct to consumers without clinical interpretation.

How to evaluate a longevity claim

The longevity market moves faster than the evidence. A few questions filter most of it.

  • What is the outcome? A change in a biomarker is not the same as living longer or better.
  • What species? Many claims rest on worms, flies, or mice.
  • How many people, and for how long? Small, short studies rarely support big claims.
  • Compared with what? No control group means limited conclusions.
  • Who benefits financially? Products sold by the person citing the research deserve extra scrutiny.
  • Is it plausible that a single compound outperforms not smoking and exercising? Almost never.

Ask a clinician about anything you plan to take, especially alongside prescribed medicines. Do not stop prescribed treatment in favour of a longevity protocol.