Sleep. We know we need it and feel better when we get enough – and feel terrible when we are sleep-deprived -but even experts aren’t entirely sure WHY we sleep.
Sleeping, like eating, is regulated by powerful internal drives. Just as your body will let you know when it needs nourishment, it will let you know when you need rest.
The average person spends about a third of their life sleeping, which equates to around 25 years. A lack of adequate sleep can affect judgment, mood, ability to learn and retain information, and may increase the risk of serious accidents and injury.
In the long term, chronic sleep deprivation may lead to a host of health problems including obesity, diabetes, cardiovascular disease, and even early mortality.
Total sleep deprivation leads to death after about two to four weeks.
We know that sleep is vital to mental and physical health, and that it feels great to get a good night’s rest.
Ongoing research continues to reveal more about snoozing, and some of their findings are intriguing – and quite surprising.
Here are 5 things you probably didn’t know about sleep:
1) Your brain never sleeps
You might think, given how crucial sleep is for rest and restoration, that your brain might take a break while you are dozing.
But that’s not the case.
While you are sleeping, your brain remains active. In fact, during sleep, neurons in your brain fire almost as much as they do while you are awake.
2) Your brain processes information and makes decisions while you slumber
Your brain can process information while you are sleeping, according to a new study published in the journal Current Biology.
The researchers showed that complex stimuli can not only be processed while we sleep but that this information can be used to make decisions, similar to how it does when we are awake.
Here’s how they conducted their study:
The researchers asked participants to categorize spoken words that were separated into different categories — words referring to animals or objects; and real words vs. fake words — and asked to indicate the category of the word they heard by pressing right or left buttons. When the task become automatic, the subjects were asked to continue but also told that they could fall asleep (they were lying in a dark room). When the subjects were asleep, the researchers began introducing new words from the same categories. Brain monitoring devices showed that even when the subjects were sleeping, their brains continued to prepare the motor function to create right and left responses based on the meaning of the words they heard. (source)
What is especially fascinating is that when the participants woke up, they didn’t remember the words they’d heard while asleep:
“Not only did they process complex information while being completely asleep, but they did it unconsciously,” researchers Thomas Andrillon and Sid Kouider write in the Washington Post. “Our work sheds new light about the brain’s ability to process information while asleep but also while being unconscious.”
2) Recovery of forgotten skills can happen during sleep
Consolidation is a neurological process that involves gradually converting information from short-term memory into long-term memory. In other words, it is how a memory becomes stable.
Experts believe that sleep plays a crucial role in the consolidation process. In fact, one of the major theories of sleep suggests that sleep exists as a way to process and consolidate information we gain while awake.
Sleep before AND after learning is essential for forming and storing information.
3) Ah-ha! moments are created while you snooze
REM sleep (the restorative kind of sleep) helps you solve problems by stimulating associative networks, allowing the brain to make new and useful associations between unrelated ideas.
A 2007 University of California at Berkeley study found that sleep can foster “remote associates,” or unusual connections, in the brain – which could lead to a major “a-ha” moment upon waking. After waking up, people are 33 percent more likely to make connections between seemingly distantly related ideas.
4) Clean up on aisle 1!
Most of your body’s waste and toxin removal is done by your lymphatic system. Your brain has a different system it uses for cleaning things up – a system known as the glymphatic system. It is composed of cerebrospinal fluid rather than lymph, and it works while you are sleeping.
A 2013 study conducted at the University of Rochester Medical Center (URMC) found that during sleep, the brains of mice clear out damaging molecules associated with neurodegeneration. Amazingly, the space between brain cells actually increased while the mice were unconscious. This allowed the brain to flush out the toxic molecules that accumulated during waking hours.
The study also showed that the brain’s cells shrivel up by 60% while we sleep – this allows it to clean up some “cellular garbage.” Researchers believe that all this housekeeping is one of the reasons the brain uses about as much energy while in sleep as it does when we are awake.
During sleep, proteins that are responsible for Alzheimer’s disease and other neurological disorders are also removed more efficiently from the brain than when we are awake.
5) Less sleep, more cravings…and more body fat
According to a new study, when sleep-deprived, overweight adults got an average of 96 extra minutes of sleep per night, it reduced their cravings for sweet and salty junk food by 62 percent and reduced their overall appetite by 14 percent.
Study author Dr. Esra Tasali, an assistant professor of medicine at the University of Chicago Medicine, explained the reason:
When we are sleep deprived, we incur a metabolic cost for being awake. We tend to compensate for this extra energy expenditure by eating. With all the tempting snack foods so widely available, we tend to overeat and choose unhealthy foods. But extra sleep can help reduce temptation.
Previous research has shown that people who get less than six hours of sleep per night are at an increased risk for gaining weight and obesity.
Most of what we know about sleep was discovered through research done over the last 25 years. Scientists still aren’t entirely sure why we sleep, but one thing is for certain: sleep is vital to our health and well-being.
For more information on the importance of sleep and tips on how to naturally improve the quality and quantity of your sleep, please read Natural Ways to Improve Sleep.