Excessive sleeping on a regular basis may predict the onset of dementia. Photo courtesy of Pixabay, Public Domain

Sleep deprivation is something we are all familiar with. But while most folks know, or have experienced, the day-time sleepiness, fatigue and even grumpiness that come from a lack of sleep, not many would be aware that it can also cause depression, age your skin, or that it makes you dumb.

Now a new study says that lack of sleep can also cause the brain to switch to cannibal mode. Researchers at the Marche Polytechnic University in Italy, led by Michele Bellesi, found that a type of cells in the brain, called astrocytes, go into overdrive in mice that are sleep deprived.

Astrocytes destroy worn-out brain cells and clean the debris out of brain — in normal situations — helping the brain stay in shape. But when the mice were kept awake, to mimic chronic sleep-loss, the researchers found that astrocyte activity had increased in their brains.

About 8 percent of the synapses showed astrocyte activity in mice that had lost 8 hours of sleep, compared to 6 percent in those that had enjoyed an undisturbed sleep. It rose to 13.5 percent in mice that were chronically sleep-deprived.

What this suggests is astrocytes are breaking down more of the brain's neural connections when the animal is sleep deprived.

“We show for the first time that portions of synapses are literally eaten by astrocytes because of sleep loss,” Bellesi told the New Scientist.

But the danger is more in the detail, as always. Much of the astrocyte activity was on the largest synapses, the ones Bellesi compared to old pieces of furniture that would need more attention and cleaning. But the team found that microglial cells, which prowl the brain for damaged cells and debris, had also become more active in sleep-deprived mice. These cells have been linked to brain disorders, like Alzheimer’s, and lack of sleep has been linked to dementia in other studies.

So, the damage from that graveyard shift may be much more than the irritation and drowsiness that will dog you for the next few days.

But can the effects of sleep deprivation be reversed if you sleep more? The plain answer is we still don't know. Bellesi plans to investigate next how long the effects of sleep deprivation last.

But a study published in the the journal Sleep in 2010, which analyzed the results of several other studies on sleep, may hold a clue to this question.

How much sleep do you need?

Much research has gone into this topic, and a team of researchers from the United Kingdom and Italy that analyzed data from 16 studies done over a quarter of a century found that those who generally sleep for less than six hours a night were 12 percent likely to experience a premature death.

And that the risk rose to 30 percent — in those who slept more than eight to nine hours a night.

What that means is that an average adult needs about 7-8 hours of sleep each night. The study covered more than 1.3 million people and more than 100,000 deaths.

But the findings of this study could also be bad news for those that hope to sleep longer to catch up on their sleep. Because trying that would also harm your health.

So here’s the key takeaway: get enough quality sleep. Your body needs it. And you cannot make up for those sleep-deprived nights. Trying to do that will only kill you faster!