As you grow older, the number of birthdays you’ve had doesn’t always match how your body feels. That’s because there’s more than one way to measure age. While chronological age tracks the years since birth, biological age reflects how your body is actually holding up. Some people might be 65 years old on paper, but their bodies show signs of someone much younger—or much older.
The science behind biological age
Biological age shows how much your body has aged based on physical and cellular wear and tear. It’s influenced by things like lifestyle, environment, and genes. Researchers have developed ways to measure this aging process. Two key tools stand out: the frailty index and telomere length.
Telomeres are the protective caps at the ends of your chromosomes. Over time, they get shorter with each cell division. When they become too short, cells can’t divide properly, which is a hallmark of aging. Telomere shortening reflects changes at the cellular level.
