The molecular basis of aging

What makes this fascinating

• The hallmarks of aging — Researchers catalog a dozen shared processes — telomere loss, senescent cells, epigenetic drift — but not which are causes and which are symptoms.

• Program or wear-and-tear? — Is aging an evolved program or just accumulated damage? The answer decides whether it can ever be slowed or reversed.

• Already reversible in the lab — Cellular reprogramming and senolytic drugs have extended healthy lifespan in mice; translating that to humans is the open frontier.

Frequently asked questions

What causes aging?

Aging stems from accumulating molecular and cellular damage — DNA damage, telomere shortening, protein misfolding, cellular senescence, and mitochondrial decline. Whether these are root causes or downstream symptoms of a deeper program is unresolved.

Can aging be slowed or reversed?

In animals, interventions like caloric restriction, senolytics, and partial cellular reprogramming have extended lifespan or reversed some markers. Whether human aging can be substantially slowed or reversed is still an open question.

Is aging a disease?

That is debated. Some researchers argue aging should be treated as a disease because it is the primary risk factor for cancer, heart disease, and dementia; others view it as a natural process.

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