The Nuance
Why Do We Sleep? Science May Have Finally Figured It Out
Your brain is equipped with a waste management system that does most of its work while you slumber
Two centuries ago, the Scottish physician Robert Macnish theorized that the purpose of sleep was to “renovate the mind” by offering it a period of deep repose.
The idea that sleep helps rejuvenate a weary brain had been around long before Macnish’s time. But as recently as 20 years ago, sleep scientists still readily admitted that they did not understand the fundamental purpose of sleep.
For decades, we’d recognized that some important biological processes take place during sleep, and that a lot goes wrong with us when we don’t get our ZZZs. But none of this explained just why human beings — and pretty much every other type of beast, bird, or bug on Earth—spends such a large portion of their lives in slumber.
The discovery of a hidden brain system may finally provide the answer.
The metabolic and cellular processes that keep you alive are not perfectly efficient. They produce waste.
Fortunately, your body is equipped with a kind of waste management system. It’s called the lymphatic system, and its network of fluids…
