A survey of experts convened at a major scientific conference revealed a surprising lack of consensus on even the most basic questions surrounding aging, prompting debate about the field’s future direction and the potential for therapeutic interventions. The Gordon Research Conference on Energetic Materials, held in Newry, Maine, posed nine questions to 103 attendees, ranging from defining aging itself to identifying its causes and determining when it begins. Results, published in the journal PNAS Nexus and highlighted by Nature, showed that no single answer garnered support from more than 30% of respondents on any given question.
The ambiguity extends to whether a unified understanding of aging is even necessary. The study’s authors noted that the lack of agreement could hinder research and potentially fragment funding, while some experts argue that a rigid definition may stifle progress. “The most prevalent human mortality risk factor — aging — seems to still be hidden in the mist,” the PNAS Nexus article states. The study involved 82 co-authors and acknowledged that no treatment has yet been proven to slow the aging process in humans.
Despite the survey’s findings, some researchers expressed surprise at the level of disagreement. Manuel Collado, group leader of the cell senescence, cancer and aging laboratory at the Spanish National Research Center’s National Center for Biotechnology (CNB-CSIC) and Center for Research in Molecular Medicine and Chronic Diseases (CiMUS) at the University of Santiago de Compostela, argued that a substantial consensus already exists. “This study aims to shake things up, but it stems from a desire to self-punish. Of course Notice variations, but there is great consensus on aging,” he said. Mariona Jové, professor at the University of Lleida and scientist at the Lleida Biomedical Research Institute, echoed this sentiment, stating she was “surprised” by the results, as “pretty much everyone involved explains it in a similar way.”
However, Juan Manuel Pérez Castejón, a geriatrician and vice-president of the Spanish Society of Geriatrics and Gerontology (SEGG), cautioned that the ambiguity could have practical consequences. “While there is a consensus that aging can be studied experimentally, the ambiguity evident in the research may hinder studies and fragment project funding, due to the lack of a common roadmap,” he said.
The survey revealed a wide range of perspectives on what constitutes aging. While the most common response – selected by 30% of respondents – defined it as “a loss of functionality of the cells and tissues with the passage of time,” other definitions focused on the accumulation of damage, overall changes, health status, or increased risk of disease, and mortality. Some offered a broad definition as a “deviation from the ideal state.”
Similarly, identifying the causes of aging proved contentious. Approximately 30% of respondents attributed it to the accumulation of damage, while others pointed to evolutionary factors, molecular mechanisms, or more general influences. Notably, six participants simply responded, “I don’t know.” The authors suggest this lack of consensus points to divergent research strategies and objectives.
The question of when aging begins also elicited varied responses. The most popular answer, chosen by 22% of respondents, was age 20. However, significant portions believed it began much earlier – in the third week after conception (18%), at conception itself (16%), or even before, with the formation of specialized sex cells (13%).
The survey also touched on the controversial question of whether aging is a disease. Responses were nearly evenly split between those who affirmed it was, those who denied it, and those who remained neutral. Collado and Jové both stated unequivocally that aging is not a disease.
The study’s authors also explored the validity of “molecular clocks” – biomarkers used to measure aging – and whether improvements in these markers after lifestyle changes, such as quitting smoking, equate to actual rejuvenation. There was no consensus on this point.
Ironically, when asked whether reaching a consensus on the definition of aging was necessary, just over 50% of respondents answered in the affirmative, while the remainder expressed doubt or uncertainty. A 2023 article by two of the study’s authors argued that consensus was crucial for enhancing the field’s credibility and preventing the proliferation of pseudoscientific treatments. Collado, however, cautioned against “exaggerated reevaluation,” suggesting it could breed mistrust and create opportunities for unsubstantiated claims.
Despite the lack of consensus on fundamental definitions, researchers have identified at least 10 known interventions that can extend the lifespan of laboratory animals, including pharmaceuticals like metformin and rapamycin, senolytics, cell reprogramming using Yamanaka factors, and calorie restriction. However, the study’s authors emphasize that no effective treatment has yet been proven to slow or reverse aging in humans.
Collado attributes the scarcity of human breakthroughs to the relative newness of aging research, noting that it was largely considered immutable until the late 1980s. He believes that significant progress has been made in understanding aging mechanisms in the past two decades. A landmark article co-authored by Spanish researchers Carlos López Otín, María Blasco, and Manuel Serrano has identified 12 “canonical mechanisms” of aging.
The conference itself, where the survey was conducted, was primarily scientific in nature, with limited discussion of clinical applications or lifestyle factors. More than half of the respondents were laboratory directors and postdoctoral researchers, nearly a quarter were doctoral candidates, and 13% represented the private sector. Notably, healthy habits and social determinants of health were not discussed, despite their demonstrated impact on longevity. Pérez Castejón emphasized the importance of considering these factors, stating, “It may be that zip code matters more than genetic code, as our colleagues specializing in family and community care are well aware.”
The question of whether interventions can truly “extend life” or simply maximize the lifespan dictated by natural limits remains open. Collado believes there is no inherent genetic limit to human lifespan, while Jové suggests a theoretical maximum age of around 122 years, based on observed longevity records. Pérez-Castejón concluded, “Geriatricians and gerontologists aren’t anti-aging; we believe in aging well,” aiming for “dying of old age, not of illness.”
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