When the truth itches, it's false
Our bodies — and stop me if you've heard this one — replace all of their cells every seven years. You've heard that one, right? Yeah, me too.
It's not true.
Some parts of our bodies never replace cells, like our brains and eye lenses, says Dr. Jonas Frisén of Sweden. What we get at birth is what we're stuck with, and it's all getting older every second.
On the other hand, the lining of the small intestine replaces itself about once a week, says QueeLim Ch'ng of King's College London, and the skin and liver only replace cells when damage occurs. The skin, which...