The Sleepy Brainwash

Why do we sleep? Sounds like a stupid question. We sleep because we feel sleepy, buddy.

- Yes, yes. But why do we feel sleepy?
- Now you are wasting my time, mister.

We spend a third of our life sleeping. So sleep must be doing something very important to us.
Scientists are trying to find out what benefits sleep has. One such very important benefit has been found recently. Sleep washes our brain of harmful chemicals.

Brain needs a lot of fuel to do its job. You know that our body uses glucose as the fuel. As much as 20% of all glucose consumed by the body is used by brain alone! Naturally, all this fuel burning leads to waste products. These are toxins and have to be removed.

Researchers studied mice and found that these toxins are removed during sleep. When the body is awake, brain has to see and think and do a lot more work. Busy with all this work, it cannot do the cleaning. Brain really is just like us working householders, postponing the cleaning to weekend, isn't it?

This is an important function of sleep, and scientists say that there will be many more. Some scientists think that when the toxins build up, we feel sleepy. So it's not a stupid question, after all.