A biogerontologist at the University of Birmingham argues that aging is less like a car rusting and more like a factory that never shuts down its production line. The paper traces the history of “programmatic” theories of aging, centered on the late Mikhail Blagosklonny’s hyperfunction theory, which holds that the same growth and developmental programs that build a young body keep running past their useful window and, in doing so, drive the diseases of old age. The strongest evidence cited is that rapamycin, a drug that dials down the growth-signaling mTOR pathway, remains the most reliable life-extending compound known, alongside the finding that turning down growth hormone and IGF-1 signaling extends lifespan in mice. The piece is a conceptual argument and an appreciation of Blagosklonny’s legacy, not a new experiment.
For most of the last century, the textbook story of why we grow old has been a story of damage. Free radicals nick our DNA, proteins misfold, mitochondria falter, and the accumulated wreckage eventually overwhelms the body’s ability to repair itself. It is an intuitive picture, and it is almost certainly part of the truth. But a competing idea has been gaining ground, and this paper by João Pedro de Magalhães is both a history of that idea and a case for taking it seriously.
The competing idea is called the hyperfunction theory, and its central claim is provocative: much of aging is not caused by damage at all. It is caused by biological programs working too hard for too long. The programs that drive growth and development in youth do not politely switch themselves off once the job is done. They keep running. In a young organism this signaling builds tissues and drives reproduction. In an old one, the same continued signaling manifests as enlarged organs, overgrown cells, chronic activation, and eventually the familiar diseases of age. Blagosklonny called this a quasi-program, meaning a program that was never selected to produce aging but does so as a side effect because evolution had no reason to turn it off after reproduction.
The theory rests on a piece of evolutionary logic from George Williams called antagonistic pleiotropy: traits that help you when you are young and fertile can hurt you later, and natural selection will still favor them because it cares mostly about the young. The mechanistic heart of the modern version is the mTOR pathway, a master regulator of cellular growth. The single most persuasive piece of supporting evidence is pharmacological. Rapamycin, which inhibits mTOR, is the most effective and reproducible lifespan-extending drug found to date. Add to that the observation that mice with reduced growth hormone or IGF-1 signaling live substantially longer, and that lifelong caloric restriction extends lifespan, and a pattern emerges: turn down the growth programs, and animals live longer.
De Magalhães is careful and, to his credit, not triumphant. He argues mTOR alone cannot explain why a mouse ages roughly thirty times faster than a human, and he proposes that the genome and epigenome act as the true master regulators, an idea he calls the software design flaw hypothesis. He also concedes the theory’s biggest weakness plainly: its direct relevance to human disease is far from established, and clear examples of hyperfunction-driven pathology, such as presbyopia and thymic involution, remain exceptions rather than the rule. Aging, he concludes, is probably a hybrid of programmatic and damage-based processes, and working out their relative contributions is the real task ahead.
Actionable Insights
Read honestly, this paper offers a framework rather than a protocol, so the take-home messages are indirect. The practical thread is that the interventions the author treats as the strongest empirical support are ones a longevity-minded reader already knows: mTOR inhibition, reduced growth signaling, and caloric restriction. The magnitude of these effects, drawn from the studies the paper cites rather than from the paper itself, is what makes them worth attention.
Rapamycin is the headline. In the NIA Interventional Testing Program (Harrison et al., Nature 2009, cited here as reference 38), rapamycin started late in life raised median lifespan by roughly 14 percent in female and 9 percent in male genetically heterogeneous mice. In human terms that framing would be an extra several years, though no human lifespan data exist and this remains a rodent effect.
Reduced growth hormone and IGF-1 signaling produces the largest effects in the mouse literature the author leans on, with some dwarf and growth-hormone-receptor-knockout models living on the order of 40 to 50 percent longer than controls. That is a very large effect size for a lifespan intervention, but it comes with the trade-off of a small body and altered metabolism.
The unifying, low-cost, human-relevant lever remains blunting chronic growth signaling: not overeating, avoiding sustained high protein and insulin excursions, and not aggressively maximizing growth. The theory reframes why this helps. You are not just cleaning up damage, you are turning down a program that is running past its window.
Context and Source
- Open Access Paper: A brief history of the hyperfunction theory of aging and future directions.
- Author and institution: João Pedro de Magalhães, Genomics of Ageing and Rejuvenation Lab, Department of Inflammation and Ageing, University of Birmingham, United Kingdom.
- Journal: Aging (also styled Aging-US), published July 24, 2026.
- Article type: Research Perspective (review and opinion), single author.
- Impact evaluation: The most recent Journal Impact Factor on record for Aging-US is 3.9 (2023 JIF), with a 2025 CiteScore of approximately 5. Historically the JIF has ranged from roughly 3.9 to 6.4 over the past decade. Using the standard framing: the impact score of this journal is approximately 3.9 to 5, evaluated against a typical high-end range of 0 to 60+ for top general science journals, therefore this is a Low-to-Medium impact journal.