Disagreement on foundational principles of biological aging

Abstract

To gain insight into how researchers of aging perceive the process they study, we conducted a survey among experts in the field. While highlighting some common features of aging, the survey exposed broad disagreement on the foundational issues. What is aging? What causes it? When does it begin? What constitutes rejuvenation? Not only was there no consensus on these and other core questions, but none of the questions received a majority opinion-even regarding the need for consensus itself. Despite many researchers believing they understand aging, their understanding diverges considerably. Importantly, as different processes are labeled as "aging" by researchers, different experimental approaches are prioritized. The survey shed light on the need to better define which aging processes this field should target and what its goals are. It also allowed us to categorize contemporary views on aging and rejuvenation, revealing critical, yet largely unanswered, questions that appear disconnected from the current research focus. Finally, we discuss ways to address the disagreement, which we hope will ultimately aid progress in the field.

Fig. 1.

Survey participants.

Fig. 2.

Word clouds of responses to questions on foundational issues in the aging field.

Fig. 3.

“When does human aging begin?” There were nine response options given, with eight receiving responses and plotted as a proportion of one (nobody responded that aging begins at 30 years).

Fig. 4.

Responses to questions. Each question (shown above the panel) could be answered with strongly disagree, disagree, neutral, agree, and strongly agree. Statistical significance of difference between average response and neutral opinion is reflected with asterisks. * P.adjusted < 0.05; ** P.adjusted < 0.01; *** P.adjusted < 0.001.

Fig. 5.

Relationship between different responses and respondents’ characteristics. A). Correlation between ordinal responses. B) Odds ratios. Odds ratios show how agreement with the statements is affected by other responses and by respondents’ characteristics. The only significant association is between positively answering questions on whether aging is a disease and whether lifespan will increase by 10 years or more in the next 20 years.

Fig. 6.

Different views on the nature of aging. COVID-19 is shown for comparison. This disease is caused by SARS-COV-2, but its symptoms manifest phenotypically once the disease progresses. Accordingly, it may be targeted with antiviral approaches or with supportive therapy. Likewise, aging may be viewed as the accumulation of molecular damage and as functional decline, and it may accordingly be targeted by slowing damage accumulation or slowing phenotypic manifestations.