concept

Hallmarks of aging

A classification framework that breaks biological aging into roughly a dozen interconnected damage processes rather than treating it as one clock. The causes include genomic instability, telomere attrition, epigenetic drift, loss of the machinery that keeps proteins correctly folded, and declining clearance of damaged organelles. The responses include deranged nutrient sensing, failing mitochondria, and cellular senescence. The systemic consequences include stem-cell exhaustion, loss of coordinated signalling between cells, chronic low-grade inflammation, and microbiome imbalance. The value of the framework is that it shows why a single molecule is unlikely to halt aging: stopping it outright would mean neutralising several independent damage pathways at once, across every cell lineage.