An editorial argues geroscience should stop splitting hairs between lifespan and healthspan

Impact Journals LLC

Geroscience - the field that studies aging as the root driver of chronic disease - has a measurement problem. Researchers talk about extending lifespan. They talk about extending healthspan. They debate which matters more. And in the process, according to a new editorial, they have splintered a field that should be unified around a single objective.

The editorial, published March 10, 2026, in Volume 18 of Aging-US, is titled "Healthy life extension: Geroscience's north star." Its author, David A. Barzilai - affiliated with the Geneva College of Longevity Science, Healthspan Coaching LLC, and Harvard Medical School - argues that the field should stop treating lifespan and healthspan as competing priorities and instead adopt health-adjusted longevity as its single metric of success.

The gap between living longer and living well

Barzilai's argument starts with data. Global life expectancy has increased substantially over the past century, but healthy life expectancy has not kept pace. People are living longer, but the additional years often come burdened with disability, chronic disease, and loss of independence. The gap between total lifespan and healthy lifespan has widened.

Metrics like HALE (health-adjusted life expectancy) and QALYs (quality-adjusted life years) attempt to capture this distinction by weighting survival time against functional status. Barzilai argues these should be the primary endpoints for geroscience research rather than raw lifespan or isolated biomarkers of aging.

"We should treat healthy life extension as the goal and define success as health-adjusted longevity: extending lifespan while proportionally expanding function, resilience, and independence," Barzilai writes.

Rapamycin in mice, mTOR inhibition in humans

The editorial reviews specific evidence from the field. In animal research, targeting conserved aging pathways has produced replicable lifespan gains in mammals. Rapamycin, an mTOR inhibitor originally developed as an immunosuppressant, has consistently extended lifespan in mouse studies - one of the few interventions to do so with reproducible results across laboratories.

On the human side, the evidence is earlier-stage but suggestive. Barzilai highlights studies showing that mTOR inhibition improved immune responses to influenza vaccination in older adults - a finding that demonstrates aging-biology interventions can produce measurable clinical effects on shorter timelines than a full lifespan study would require.

This matters because human lifespan studies are nearly impractical. Following a cohort for decades to determine whether an intervention extends life is prohibitively expensive and slow. The field needs endpoints that are meaningful, measurable within realistic trial durations, and that map to the outcomes people actually care about: fewer years of disability, preserved cognitive function, maintained independence.

A tribute and a call to action

The editorial is written partly as a tribute to the late Mikhail Blagosklonny, a biologist whose work on mTOR signaling and the concept of "hyperfunction" in aging helped shape modern geroscience. Blagosklonny argued that aging is not simply wear and tear but an active continuation of growth-promoting pathways beyond their useful developmental window - a framework that has influenced how researchers think about interventions like rapamycin.

Barzilai builds on that foundation with specific calls for action. He urges the field to pursue "moonshot"-level investment in aging biology, including larger and better-funded basic research programs, clinical trials designed around health-adjusted survival endpoints, and translational pipelines capable of moving robust mammalian findings toward human studies.

The editorial also stresses the need for replicable mammalian lifespan data as the evidentiary standard before advancing to human trials. Too often, Barzilai suggests, early-stage findings generate excitement without the kind of rigorous, multi-site replication that should precede clinical translation.

What the editorial does not resolve

As an editorial rather than a primary research paper, the piece advocates a position rather than presenting new data. Several of the challenges it identifies - how to design affordable human trials, how to validate surrogate endpoints for healthy aging, how to secure sustained public funding for aging research - remain open problems without clear solutions.

The call for health-adjusted longevity as the primary metric is conceptually appealing but practically complex. HALE and QALYs are useful population-level statistics, but translating them into individual clinical trial endpoints requires defining what counts as "healthy" at different ages, accounting for subjective quality-of-life assessments, and standardizing measurements across diverse populations. These methodological challenges are acknowledged implicitly in the editorial but not addressed in detail.

The comparison to a "moonshot" also carries rhetorical weight but limited specificity. How much funding would constitute a moonshot for aging research? Which agencies or organizations should provide it? How should resources be allocated between basic science, translational research, and clinical trials? These are questions the editorial raises more than answers.

There is also an inherent tension in calling for both rapid translation and rigorous replication. The field has historically suffered from premature enthusiasm about interventions that looked promising in mice but failed to translate to humans. Balancing the urgency to act against the discipline to replicate remains an unresolved challenge.

A field in search of focus

Geroscience sits at an unusual inflection point. The basic science has advanced substantially - the role of mTOR, senescent cell accumulation, mitochondrial dysfunction, and other hallmarks of aging are better understood than ever. Several candidate interventions have strong preclinical evidence. Public interest in longevity has surged, driven partly by high-profile figures investing in aging research.

But the field lacks consensus on what it is trying to achieve and how to measure whether it has succeeded. Barzilai's editorial is a direct attempt to resolve that ambiguity: stop debating whether lifespan or healthspan matters more, combine them into a single metric, and organize the field's resources around extending years worth living.

Whether the field will rally around that framing remains to be seen. But the underlying argument - that adding sick years to the end of life is not a victory - is difficult to dispute.