From gerontology to geroscience: a synopsis on ageing

Abstract

Biological ageing can be tentatively defined as an intrinsic and inevitable degradation of biological function that accumulates over time at every level of biological organisation from molecules to populations. Senescence is characterised by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death. With advancing age, all components of the human body undergo these cumulative, universal, progressive, intrinsic and deleterious (CUPID) changes. Although ageing is not a disease per se, age is the main risk factor for the development of a panoply of age-related diseases. From a mechanistic perspective, a myriad of molecular processes and components of ageing can be studied. Some of them seem especially important and they are referred to as the hallmarks of ageing. There is compelling evidence that senescence has evolved as an emergent metaphenomenon that originates in the difficulty in maintaining homeodynamics in biological systems. From an evolutionary perspective, senescence is the inevitable outcome of an evolutionarily derived equilibrium between the amount of resources devoted to somatic maintenance and the amount of resources devoted to sexual reproduction. Single-target, single-molecule and disease-oriented approaches to ageing are severely limited because they neglect the dynamic, interactive and networking nature of life. These limitations notwithstanding, many authors promote single-target and disease-oriented approaches to senescence, e.g. repurposed drugs, claiming that these methods can enhance human health and longevity. Senescence is neither a disease nor a monolithic process. In this review, the limitations of these methods are discussed. The current state of biogerontology is also summarised.

Exploring the effects of birth order on human lifespan in Polish historical populations, 1738–1968

“…Human lifespan is a multifactorial trait that is affected by genetic background, epigenetic mechanisms, lifestyle and environmental factors (Govindaraju et al 2015;Chmielewski 2020;Costa et al 2019). While the relationships between birth order and later outcomes in life, includ-ing health and wealth, have been the subject of investigation for several decades, little or no data exist regarding the relationship between birth order and longevity in Poland.…”

“…Moreover, the idea that a single trait, such as being a first-born child, can con-fer longevity, is flawed. Like ageing, life is a complex interplay of various elements, including extrinsic (environmental) and intrinsic (genetic and epigenetic) processes and factors (Chmielewski 2017(Chmielewski , 2020Whitwell et al 2020). Although early life events have some health impacts later in life (Bartke 2015;Chmielewski 2016;Hemati et al 2021), many other factors, including the genetic background, the environment, exposure to carcinogens and other harmful substances, educational attainment, SES and lifestyle, play a key role in shaping health outcomes (Govindaraju et al 2015;Costa et al 2019).…”