Here, we have attempted to identify and categorize the
cellular and molecular hallmarks of aging. We propose
nine candidate hallmarks that are generally considered
to contribute to the aging process and together
determine the aging phenotype (Figure 1).
Given the complexity of the issue, we have emphasized current understanding of mammalian aging while recognizing pioneer insights from simpler model organisms (Gems and Partridge, 2013; Kenyon, 2010). Each hallmark should ideally fulfill the following criteria: (1) it should manifest during normal aging; (2) its experimental aggravation should accelerate aging; and (3) its experimental amelioration should retard the normal aging process and hence increase healthy lifespan. This set of ideal requisites is met to varying degrees by the proposed hallmarks, an aspect that will be discussed in detail for each of them. The last criterion is the most difficult to achieve, even if restricted to just one aspect of aging. For this reason, not all of the hallmarks are fully supported yet by interventions that succeed in ameliorating aging. This caveat is tempered by the extensive interconnectedness between the aging hallmarks, implying that experimental amelioration of one particular hallmark may impinge on others.
The Northeastern woman went to the drugstore to get her medication and suddenly fell to the ground and died suddenly!東北大媽去藥店拿藥，突然倒地猝死！ pic.twitter.com/3sKGVwgRVG
