The 3 best predictors of how well you’ll age

Explore how our bodies change and age over time, and the three common markers scientists use to measure aging.

If you want to learn a tree’s age, you can count their rings. When it comes to humans, scientists have yet to find any visible traits that mark our age with the same specificity. But in the past few decades, they’ve discovered small, invisible markers hidden within the body that do change over time.