Are you taking sleep tablets? Well, they may allow you to sleep peacefully but there is a flip side.

Every night our brain undergoes a process of rinsing. It has been known about for a decade now — thanks to the work of Dr Maiken Nedergaard at the University of Rochester — that when we sleep the ‘glymphatic system’ in the brain releases the cerebrospinal fluid to flush out toxic chemicals that have entered the brain because of our metabolic activities. 

New research has discovered how the efficiency of the glymphatic system is regulated by a chemical called norepinephrine, which is both a hormone and a neurotransmitter. The higher the levels of norepinephrine, the more alert you are. 

When you take a sedative, it depresses the level of norepinephrine, which brings down your alertness and lets you drift off into sleep. But low norepinephrine means the glymphatic system is not working well which, in turn, means the cleansing of the brain is not happening as it should. 

This was discovered through experiments on mice by a group of researchers that included Nedergaard, and their findings have been published in the journal Cell. But the researchers say this pretty much holds for humans too. 

Moral of the story: Junk your sleeping tablets and allow yourself to be brainwashed.