What Do Cells Have to Do with Aging?

Cellular senescence is a primary driver of the aging process, and has been described as the “causal nexus,” which links cellular damage with the larger, anatomical effects of aging1. Senescent cells do not directly cause aging, but instead have a cumulative effect leading to larger, more visible consequences of tissue breakdown that are the signs and symptoms of old age—sagging, wrinkled skin, decreased muscle mass, weakened immunity, etc.

This mechanism explains how microscopic changes to our trillions of cells slowly manifest in the gradual, almost invisible process of aging. Researchers have also observed that senescent cells differ from their younger counterparts. Cells that contain chromosomes with telomeres approaching a critically short length undergo changes that result in further damage to the organism. Whereas young cells secrete proteins that maintain healthy, functioning tissue, cells approaching senescence begin to secrete inflammatory cytokines that break down these proteins. Thus, many scientists believe that the subcellular biological changes that precede senescence increase our vulnerability to disease. Decades of research published in scientific journals has shown that shorter telomeres are associated with many age-related diseases and mortality in general. Researchers have also studied how certain lifestyle, genetic, environmental, and other factors are correlated with telomere length. Knowing your telomere length gives you a uniquely integrated view of these factors.