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  • 40 percent of Americans are sleep deprived. Many get less than five hours of sleep per night, and research shows that getting less than six hours of sleep leaves you cognitively impaired
  • Sleep deprivation has been linked to obesity, diabetes, cardiovascular disease, Alzheimer’s, cancer, and many other health problems, especially psychiatric disorders
  • Maintaining a natural rhythm of exposure to sunlight during the day and darkness at night is one crucial foundational component of sleeping well

What Happens to Your Body When You're Sleep Deprived?

January 17, 2015 | 341,153 views
| Available in EspañolDisponible en Español

By Dr. Mercola

According to the documentary, Sleepless in America, coproduced by the National Geographic Channel, 40 percent of Americans are sleep deprived. Many get less than five hours of sleep per night. Percentage-wise, adolescents are among the most sleep deprived.

The consequences are dire, not just for the individual who isn’t getting enough rest, but for those around them as well. While most people don’t give lack of sleep much thought, there are in fact life-threatening consequences.

Notably, “experts now believe that sleep deprivation may have played a role in the Exxon Valdez oil spill, the Staten Island ferry crash, and the Three-Mile Island nuclear meltdown,” the film states. Countless people have also lost their lives to tired drivers who simply dozed off behind the wheel.

It’s important to realize that getting less than six hours of sleep each night leaves you cognitively impaired. Sleep deprivation has also been linked to health effects such as obesity, diabetes, cardiovascular disease, Alzheimer’s,1 and cancer. Depression and anxiety disorders are also adversely impacted by lack of sleep.

The Importance of Staying in Sync with Nature

Maintaining a natural rhythm of exposure to sunlight during the day and darkness at night is one crucial foundational component of sleeping well.

This was addressed in a previous interview with researcher Dan Pardi. In it, he explains how exposure to bright daylight serves as the major synchronizer of your master clock—a group of cells in your brain called the suprachiasmatic nuclei (SCN).

These nuclei synchronize to the light-dark cycle of your environment when light enters your eye. You also have other biological clocks throughout your body that are synchronized to your master clock.

One reason why so many people get so little sleep, and/or such poor sleep, can be traced back to a master clock disruption. In short, most people spend their days indoors, shielded from bright daylight, and then spend their evenings in too-bright artificial light.

As a result, their body clocks get out of sync with the natural rhythm of daylight and nighttime darkness, and when that happens, restorative sleep becomes elusive.

An estimated 15 million Americans also work the night shift, and the adverse health effects of working nights are well documented. As just one example, three years of periodical night shift work can increase your risk for diabetes by 20 percent, and this risk continues to rise with time.

What Happens When You’re Sleep Deprived?

What makes sleep deprivation so detrimental is that it doesn’t just impact one aspect of your health… it impacts many. Among them are five major risks to your mental and physical well-being:

  1. Reaction time slows: When you’re sleep-deprived, you’re not going to react as quickly as you normally would, making driving or other potentially dangerous activities, like using power tools, risky. One study even found that sleepiness behind the wheel was nearly as dangerous as drinking and driving.2
  2. Your cognition suffers—both short- and long-term: A single night of sleeping only four to six hours can impact your ability to think clearly the next day. In one animal study,3 sleep deprived mice lost 25 percent of the neurons located in their locus coeruleus, a nucleus in the brainstem associated with cognitive processes.
  3. Hence, if you’re sleep-deprived you will have trouble processing information and making decisions. This is why it’s so important to get a good night’s sleep prior to important events at work or home.

    For example, research discussed in the film found that diagnostic mistakes shot up by 400 percent among doctors who had worked for 24 consecutive hours.

    Sleep deprived medical residents also reported a 73 percent increase in self-inflicted needle sticks and scalpel stabs, and when driving home from work, they had a 170 percent increased risk of having a serious motor vehicle accident.

    Research4 also suggests that people with chronic sleep problems may develop Alzheimer’s disease sooner than those who sleep well. One of the reasons for this is because sleep is critical for brain detoxification—a process during which harmful proteins linked to Alzheimer's are cleared out.

  4. Memory and learning declines: The process of brain growth, or neuroplasticity, is believed to underlie your brain's capacity to control behavior, including learning and memory. However, sleep and sleep loss modify the expression of several genes and gene products that may be important for synaptic plasticity.
  5. Furthermore, certain forms of long-term potentiation, a neural process associated with the laying down of learning and memory can be elicited in sleep, suggesting synaptic connections are strengthened while you slumber.

  6. Emotions are heightened: As your reaction time and cognition slows, your emotions will be kicked into high gear. This means that arguments with co-workers or your spouse are likely, and you’re probably going to be at fault for blowing things out of proportion.
  7. The amygdala controls basic emotions like fear and anger. As discussed in the film, another area of your brain called your frontal cortex, plays a key role in the regulation of emotions, and sleep is vital for its function.

    When you’re well rested, your frontal cortex is nicely connected to your amygdala—that deep emotional center—and works almost like “a break to your emotional gas pedal.”

    Sleep deprivation causes a disconnect between these two brain centers, allowing your emotions to run amok. Sleep deprivation also plays an important role in mental illness, and tends to result in more adverse psychiatric outcomes.

  8. Immune function and health deteriorates: Sleep deprivation has the same effect on your immune system as physical stress or illness,5 which may help explain why lack of sleep is tied to an increased risk of numerous chronic diseases.
  9. For example, research shows that sleeping less than six hours per night more than triples your risk of high blood pressure, and women who get less than four hours of shut-eye per night double their chances of dying from heart disease.6

You Need Around Eight Hours of Sleep Every Night

The studies are quite clear and most experts agree, you are seriously fooling yourself if you think you can do fine on less than eight hours of sleep. But eight hours of sleep is not eight hours in bed. If you go to bed at 10 pm and get out of bed at 6 am, you might say you’ve slept for eight hours. In reality, you probably spent at least 15-30 minutes falling asleep and may have woken during the night one or more times.

With the advent of fitness-tracking devices  however, we now have access to actual sleep data (and more) from wristband users. The data is quite useful on a personal level and they helped me understand that I need to start getting to sleep around 9.30 PM if I hope to get a full eight hours of sleep, which I now typically do.

The Glorification of Sleep Deprivation

According to the 2013 International Bedroom Poll by the National Sleep Foundation,7 25 percent of Americans report having to cut down on sleep due to long workdays. On average, Americans get only 6.5 hours of sleep on weeknights, but report needing 7.25 hours in order to function optimally. As noted in a previous article in The Atlantic:8

“For some, sleep loss is a badge of honor, a sign that they don’t require the eight-hour biological reset that the rest of us softies do. Others feel that keeping up with peers requires sacrifice at the personal level—and at least in the short-term, sleep is an invisible sacrifice.”

Modern man’s penchant for equating sleep with unproductiveness (if not outright laziness) can be traced back to the heyday of Thomas Edison, who was known for working around the clock. According to the featured article:9

“Edison spent considerable amounts of his own and his staff’s energy on in publicizing the idea that success depended in no small part in staying awake to stay ahead of the technological and economic competition.”  No one... did more to frame the issue as a simple choice between productive work and unproductive rest ...

Over time, children’s books and magazines began to promote this type of Edisonian asceticism... Edison encouraged all Americans to follow his lead, claiming that sleeping eight hours a night was a waste and even harmful. “There is really no reason why men should go to bed at all,” he said in 1914.”

This culture of sleep deprivation started with the invention of the light bulb, and has only gotten worse with the proliferation of light-emitting electronics, which disrupt your natural waking-sleeping cycle. The following infographic, created by BigBrandBeds.co.uk, illustrates how your electronic gadgets wreak havoc on your sleep when used before bedtime.10

The Importance of Addressing Sleep Apnea

As discussed in the film, sleep apnea is another common cause of sleep deprivation. Sleep apnea is the inability to breathe properly, or the limitation of breath or breathing, during sleep. Obstructive sleep apnea consists of the frequent collapse of the airway during sleep, making it difficult to breathe for periods lasting as long as 10 seconds. Those with a severe form of the disorder have at least 30 disruptions per hour. Not only do these breathing disruptions interfere with sleep, leaving you unusually tired the next day, it also reduces the amount of oxygen in your blood, which can impair the function of internal organs and/or exacerbate other health conditions you may have.

The condition is closely linked to metabolic health problems such as obesity and type 2 diabetes, and according to research,11 even a modest weight reduction can halt the progression of obstructive sleep apnea. Shedding excess pounds might even cure it, according to one five-year long study.12 That said, you do not have to be obese to suffer from sleep apnea. As discussed by Dr. Arthur Strauss, a dental physician and a diplomat of the American Board of Dental Sleep Medicine, factors such as the shape and size of your mouth, and the positioning of your tongue, can also play a significant role.

If your sleep apnea is related to your tongue or jaw position, specialty trained dentists can design a custom oral appliance to address the issue. These include mandibular repositioning devices, designed to shift your jaw forward, while others help hold your tongue forward without moving your jaw. Relief may also be found in the form of speech therapy treatment called oral myofunctional therapy, which helps to re-pattern your oral and facial muscles. For more information about this, please see my previous interview with Joy Moeller, who is a leading expert in this form of therapy in the US.

How to Support Your Circadian Rhythm and Sleep Better for Optimal Health

Making small adjustments to your daily routine and sleeping area can go a long way to ensure uninterrupted, restful sleep and, thereby, better health. I suggest you read through my full set of 33 healthy sleep guidelines for all of the details, but to start, consider implementing the following changes to ensure more shut-eye:

  • Avoid watching TV or using your computer in the evening, at least an hour or so before going to bed. These devices emit blue light, which tricks your brain into thinking it's still daytime. Normally, your brain starts secreting melatonin between 9 and 10 pm, and these devices emit light that may stifle that process. You can also download a free application called F.lux13 that automatically dims your monitor or screens in the evening, which can help lessen the adverse effects if you have to use them in the evening.
  • Get some sun in the morning, and at least 30 minutes of BRIGHT sun exposure mid-day. Your circadian system needs bright light to reset itself. Ten to 15 minutes of morning sunlight will send a strong message to your internal clock that day has arrived, making it less likely to be confused by weaker light signals during the night. Also, if you work indoors, make a point to get outdoors for at least a total of 30-60 minutes during the brightest portion of the day.
  • Sleep in a dark room. Even the slightest bit of light in your bedroom can disrupt your body’s clock and your pineal gland's melatonin production. I recommend covering your windows with drapes or blackout shades, or using an eye mask.
  • Install a low-wattage yellow, orange, or red light bulb if you need a source of light for navigation at night. Light in these bandwidths does not shut down melatonin production in the way that white and blue bandwidth light does. Salt lamps are handy for this purpose.
  • Keep the temperature in your bedroom below 70 degrees F. Many people keep their homes too warm (particularly their upstairs bedrooms). Studies show that the optimal room temperature for sleep is between 60 to 68 degrees F.
  • Take a hot bath 90 to 120 minutes before bedtime. This increases your core body temperature, and when you get out of the bath it abruptly drops, signaling your body that you are ready to sleep.
  • Avoid electromagnetic fields (EMFs) in your bedroom. EMFs can disrupt your pineal gland and its melatonin production, and may have other negative biological effects as well. A gauss meter is required if you want to measure EMF levels in various areas of your home. Ideally, you should turn off any wireless router while you are sleeping. You don’t need the Internet on while you’re asleep.
  • Use a fitness tracker to track your sleep. Chances are you’re not getting nearly as much sleep as you think, and using a fitness tracker that monitors your sleep can be a useful tool to help motivate you to get to bed earlier so you can get eight hours of sleep. When I first started using a fitness tracker, I was striving to get 8 hours of sleep, but my Jawbone UP typically recorded me at 7.5 to 7.75. Part of the equation too is going to bed earlier, as most of us have to get up at a preset time.

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