How Telomeres Relate to Aging

Telomeres are among the most studied structures in aging biology — small stretches of repetitive DNA at chromosome tips whose gradual erosion with each cell division has been described as a "molecular clock" of cellular aging. They have attracted enormous scientific interest because they sit at the intersection of cell division, cancer biology, and aging — and because their length is measurably influenced by lifestyle factors that we have the power to change.

WHAT ARE TELOMERES?

Telomeres are repetitive nucleotide sequences — (TTAGGG)n in humans — that cap the ends of linear chromosomes, typically repeated 1,000–2,000 times. They serve two critical functions:

Protecting chromosomes: Without telomeres, chromosome ends would be recognized as double-strand DNA breaks — triggering repair mechanisms that would fuse chromosomes together, catastrophically disrupting the genome. Telomeres form protective structures (called T-loops) with associated proteins (the shelterin complex) that prevent this recognition.