Sediment layers in rock or tree rings can hold clues to what the environment was like at different times in the past – and the same idea may even apply to your own teeth. Scientists at New York University have found that the material that makes up tooth roots preserves a lifelong record of stresses on the body, such as childbirth, illness, and even prison time.
While most of a tooth doesn’t grow once it’s popped up in your jaw, the tissue around the roots do. Known as cementum, this stuff regularly adds new layers after the tooth surfaces. And for this study, the researchers investigated the hypothesis that major physiological events would leave their mark in these layers.
To test the idea, the team examined 47 teeth from 15 different people, between the ages of 25 and 69. The life histories of all of these people were known, including things like whether they’d given birth, had major illnesses or even moved from rural to urban areas. Crucially, they also knew what ages these events had occurred.
