Sleep is one of the most essential elements of life.
Every single human has experienced it, but when it comes to sleep, there is still so much we don't know. Why, for example, do we dream? And why can some people fall asleep within seconds, while others have to count sheep for an hour before getting some rest?
As research on shut-eye continues to expand, two things remain clear: Sleep is really good for you and sleep deprivation is really bad for you. But there have been some other interesting small findings along the way as well.
In honor of World Sleep Day March 18, we rounded up a few of the major findings from the past year. When you're done, may we suggest burying yourself under the comfiest blanket you can find and celebrate the holiday the way nature intended?
1. Work should start at 10 a.m.
If you thought that starting work any time before 9 a.m. was an ungodly feat, good news: Science agrees with you.
In fact, the healthiest and most efficient time to start the work day is at 10 a.m. in order to avoid the "torture" of sleep deprivation, according to Paul Kelley, an honorary clinical research fellow at Oxford University's Sleep and Circadian Neuroscience Institute.
"It is hugely damaging on the body's systems because you are affecting physical, emotional and performance systems in the body," Kelley said during the British Science Festival. "Your liver and your heart have different patterns and you're asking them to shift two or three hours."
2. The brain has a "reset" button that can regulate sleep.
Working a graveyard shift or staying up into the wee hours of the morning can completely throw off your sleep cycle. Unfortunately, sometimes it's inevitable. But what if we could press a magic button that would reset our body, forcing us to sleep and stay awake during the hours nature intended?
Last year, researchers at Vanderbilt University found a way to control the brain's circadian clock via a "reset button" in the brain. Using mice as their test subjects, the scientists found that, by stimulating or suppressing neurons in the brain's suprachiasmatic nucleus (where the circadian clock is located), they could change when the mice naturally woke up and went to sleep. In other words, the researchers effectively "reset" their biological clock without changing anything in the mice's external environment.
While this technique is not ready for human use, it could potentially pave the way for more effective treatments for jet lag and seasonal affective disorder and reduce the negative health effects of after-hours work shifts.
3. Smartphones are seriously messing with our sleep behaviors.
Ever since the smartphone became a modern day staple, study after study has proclaimed how harmful staring at a screen before bed can be for our health. But perhaps the scariest finding of all is the fact that, despite all that research, way too many Americans are still sleeping with their phones.
A survey conducted for Bank of America's annual Trends in Consumer Mobility Report found that 71 percent of adults polled usually sleep with or next to their smartphones -- 3 percent of those people said they sleep while holding their phones, 13 percent reported they keep it in their bed and 55 percent leave it on the night sand.
What's even sadder is that almost one in four people surveyed said that, at one time or another, they've fallen asleep with their phone in hand, while 35 percent of people said their phone is the first thing they reach for when they wake up -- even before coffee, a toothbrush or their significant other.
This is proof that the research bears repeating: Using your phone in bed not only messes with your sleep, it can mess you up for the entire next day. So, seriously, cut it out.
4. The time you go to bed may determine how healthy you eat the next day.
Turns out that tonight's bedtime may impact tomorrow's food decisions.
After analyzing data from more than 850,000 Jawbone UP fitness trackers, researchers with Jawbone found that users who consistently went to bed before 11 p.m. ate healthier than their "night owl" counterparts who hit the sheets between 11 p.m. and 3 a.m. The study also found that the later a user went to bed, the more calories they logged the next day.
"If you go to bed an hour earlier, and do so consistently for a year, in theory, this could add up to [a loss of] 4-5 pounds with no changes in activity," Dr. Kirstin Aschbacher, a data scientist at Jawbone, previously told HuffPost.
These results fall in line with existing research that connects sleep behavior with food behaviors. One such study published in The American Journal of Clinical Nutrition found that people who sleep more tend to eat less saturated fat than people who get less rest. Conversely, a study from the University of California, Berkeley found that teens who stay up late are more likely to gain weight over a five-year period.
5. Sleep resets the brain's "emotional compass."
Last summer, researchers found that sleep deprivation doesn't just put you in a bad mood, it makes it harder for you to tell when others are in a bad mood, too (or a good mood, for that matter). This, as you can imagine, can make the next day a minefield of awkward social interactions.
A study from the University of California, Berkeley found that a lack of sleep may hinder a person's ability to accurately read the emotions of others by dulling the person's ability to read facial expressions.
But, on the bright side, this also means that getting good night's rest could be the secret to emotional intelligence. In the same study, researchers found that REM sleep -- a type of sleep that's associated with dreaming -- was correlated with a person's ability to accurately read facial expressions.
"Dream sleep appears to reset the magnetic north of our emotional compass," Matthew Walker, the study's senior author, said in a statement. "One question is whether we can now enhance the quality of dream sleep, and in doing so, improve emotional intelligence.”
6. Most people who are sleepwalking don't feel pain during an episode.
Here's a scary fact: One sleep study that observed 100 sleepwalkers found that 79 percent of the participants couldn't feel pain when they injured themselves during a sleepwalking episode. (This is why you really should wake up a sleepwalker, despite the myth.)
And if you thought sleepwalking is only a nighttime problem for the 1 to 15 percent of the population that suffers from the condition, think again.
Nearly half of the sleepwalkers in the study experienced chronic pain or headaches -- 22 percent of them suffered from migraines. What's more, the study found that sleepwalkers, when compared to the general population, were more likely to be tired throughout the day or experience insomnia at night.
7. Just one night of bad sleep can alter your genes.
Next time you're contemplating pulling an all-nighter, remember this: A Swedish sleep study found that it only takes one night of sleep loss to alter the genes that control your body's biological clock -- aka your "clock genes."
An analysis of the samples collected from the 15 men who participated in the two-night study revealed that one night without sleep altered the regulation and activity of these genes. Researchers also found that the lack of sleep altered the expression of the genes, or the process by which the information encoded in a gene is used.
While this isn't the first time a study found that lack of sleep alters the genes, Dr. Jonathan Cedernaes, the study's lead author, was surprised to discover that the genes could be altered so quickly.
It's just another terrifying reason we should make bedtime a priority.