Hallmarks of aging

Hallmarks of aging are something we reference a lot – and with good reason. Here’s what we’re on about…


An increasing number of studies suggest the presence of a “metabolic clock” that controls aging. This clock involves the accumulation of metabolic alterations and a decline in metabolic homeostasis and biological fitness. The key to tackling aging and promoting longevity lies in targeting the underlying age mechanisms.

The Hallmarks of Aging is a way of categorising these underlying age mechanisms; a set of nine biological processes that are thought to contribute to the overall process of aging, the hallmarks were first proposed in 2013, and they have since become a widely-accepted framework for understanding the molecular basis of aging.

The hallmarks of aging are determined mainly by our genetics, but environmental factors can cause or exacerbate them also. Each hallmark contributes to the damage that occurs and accumulates with age and is ultimately responsible for age-associated pathologies. The hallmarks of aging determine the difference between chronological age (how many years since you were born) and biological age (how the aging process has affected your body’s physical and mental functions and appearance, in short, a time-dependent decline).

There are nine cellular hallmarks of aging have been described so far: telomere attrition, genomic instability, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, loss of proteostasis, deregulated nutrient sensing, epigenetic alterations, and altered intercellular communication [1]. Metabolic alterations have been implicated in each of these processes [2].

Understanding the molecular basis of aging and the role of these nine hallmarks is important for the development of therapies to promote healthy aging and extend lifespan. Research into interventions that target these hallmarks, such as calorie restriction and certain dietary interventions, is an active area of investigation.

While nine is currently the golden number, longevity is a fast moving-science, and there are compelling arguments for adding the following:


[1] https://www.cell.com/fulltext/S0092-8674(13)00645-4
[2] https://www.cell.com/cell/pdf/S0092-8674(16)30981-3.pdf

Hallmarks of aging graphic courtesy of Carlos Lopez-Otin, et al., “The Hallmarks of Aging”, Cell 153, 2013 28