The Persistent Rhythm of Aging: Investigating the Pace of Senescence across Time and Populations

Silvio Patricio, Interdisciplinary Centre On Population Dynamics, University Of Southern Denmark

Aging is inevitable, but how fast we age remains one of the most critical and unresolved questions in demographic research. The pace of senescence, or the rate at which mortality increases with age, remains a vital topic in understanding aging across populations. While previous research has explored genetic, environmental, and socioeconomic factors, the extent to which the rate of aging varies across populations and historical periods remains unresolved. This study investigates whether the pace of aging is consistent or fluctuates across different populations by analyzing cohort mortality data from Denmark, France, Italy, and Sweden between 1850 and 1916. Using the gamma-Gompertz model to capture senescent mortality and penalized splines to model non-senescent mortality, this research adds flexibility in capturing complex, non-parametric patterns of mortality. The analysis reveals that, while minor fluctuations exist, the senescence rate remains largely stable. This finding suggests that fundamental biological mechanisms governing aging are robust, even in the face of external genetic and environmental variations. These insights help inform public health strategies aimed at improving life expectancy and contribute to the ongoing discussion about the stability of senescence across populations and time.

Keywords: Data and Methods, Mortality and Longevity, Population Ageing, Bayesian methods

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