The passage of time may be linear, but the course of human aging is not. Rather than a gradual transition, your life staggers and lurches through the rapid growth of childhood, the plateau of early adulthood, to an acceleration in aging as the decades progress.

Now, a new study has identified a turning point at which that acceleration typically takes place: at around age 50.

After this time, the trajectory at which your tissues and organs age is steeper than the decades preceding, according to a study of proteins in human bodies across a wide range of adult ages – and your veins are among the fastest to decline.