Sleep — Why You Need It and 50 Ways to Improve It
This article was previously published March 29, 2018, and has been updated with new information.
While sleep is still a largely neglected area of health, research soundly refutes the idea that sleep is “a waste of time” and can be omitted without major repercussions. On the contrary, without proper sleep, every aspect of your health will suffer adverse consequences. Estimates suggest 1 in 3 Americans gets less than seven hours of sleep a night and more than 83 million adults in the U.S. are sleep-deprived.1
Here, I’ll review some of the most important findings that have emerged in more recent years, answering key questions such as: What happens during sleep that makes it so crucial for optimal health? What are the consequences of sleeping too little or getting poor-quality sleep? How much sleep do you actually need? And, how can you improve sleep quality and quantity?
What Happens During Sleep?
Why do we sleep? For many ambitious and driven individuals, sleep can seem like an annoyance without clear purpose. Far from being a waste of time, sleep serves many important functions, and without it, your body (and mind) starts to fall apart at the proverbial seams.
In the video above, professor Matthew Walker, Ph.D., founder and director of the University of California Berkeley’s Center for Human Sleep Science and author of the book, “Why We Sleep: The New Science of Sleep and Dreams,” shares the latest discoveries about sleep and how it impacts virtually every area of your physical and mental health. For example, sleep is required for:
• Maintaining metabolic homeostasis in your brain — Wakefulness is associated with mitochondrial stress and without sufficient sleep, neuron degeneration sets in, which can lead to dementia.2,3,4 Animal research reveals inconsistent, intermittent sleep results in considerable and irreversible brain damage.
In one study, mice lost 25% of the neurons located in their locus coeruleus,5 a nucleus in the brainstem associated with arousal, wakefulness and certain cognitive processes. In a similar vein, research published in the journal Neurobiology of Aging suggests people with chronic sleep problems develop Alzheimer’s disease sooner than those who sleep well.6
• Maintaining biological homeostasis — Your body contains an array of body clocks that regulate everything from metabolism to psychological functioning.
When you upset your circadian rhythm by not getting enough sleep, the results cascade through your system, raising blood pressure, dysregulating hunger hormones and blood sugar, increasing the expression of genes associated with inflammation, immune excitability, diabetes, cancer risk and stress,7 and much more.
While the master clock in your brain synchronizes your bodily functions to match the 24-hour light and dark cycle, each and every organ, indeed each cell, has its own biological clock. The Nobel Prize in physiology or medicine in 20178 was actually awarded for the discovery of these body clocks.
Even half your genes have been shown to be under circadian control, turning on and off in cyclical waves. All of these clocks, while having slightly different rhythms, are synchronized to the master clock in your brain. Needless to say, when these clocks become desynchronized, a wide array of health problems can ensue.
• Removal of toxic waste from your brain through the glymphatic system — This system ramps up its activity during deep sleep, thereby allowing your brain to clear out toxins, including harmful proteins linked to brain disorders such as Alzheimer’s.
By pumping cerebral spinal fluid through your brain’s tissues, the glymphatic system flushes the waste from your brain, back into your body’s circulatory system. From there, the waste eventually reaches your liver, where it can be eliminated.9,10,11,12,13
• Memory formation, extracting meaning from life events and improving daytime performance — During sleep, your brain pulls together and extracts meaning from the day’s events, thereby fostering insight into the workings of your life.
Dreams play important roles as well. In addition to helping you gain insight into what’s going on in your life, tests reveal dreaming about performing an activity increases actual physical performance tenfold.14 In the dream state, your brain is actually processing information at multiple levels. Your whole brain is engaged.
Part of your brain is busy stabilizing, enhancing and integrating new memories. It’s also extracting rules and the gist of what’s going on. Then, during dreaming, old and new memories are integrated to form a new whole, and possible futures are imagined. (This is what you actually perceive as “the action” of your dream.) The sum total of these processes then allows you to see the meaning of your life.
The Consequences of Insufficient Sleep
The list above should alert you to many of the possible ramifications associated with insufficient sleep. Considering the fact that sleep plays a key role in everything from gene expression and hormone regulation to brain detoxification and cognition, it becomes clear that there aren’t many facets of your being that can skate by unscathed when you skimp on sleep. Here are some examples of the health problems linked to insufficient sleep:
Impaired memory and reduced ability to learn new things15— Due to your hippocampus shutting down, you will experience a 40% deficit in your brain with respect to its ability to make new memories when you’re sleep-deprived.
Reduced productivity at work and poor grades in school
Reduced ability to perform tasks
Reduced athletic performance
Reduced creativity at work or in other activities
Slowed reaction time, increasing your risk of accidents on the road and at work — Getting less than six hours of sleep leaves you cognitively impaired. In 2013, drowsy drivers caused 72,000 car accidents in which 800 Americans were killed and 44,000 were injured.16 This is more than died from those texting and drunk drivers combined. Sadly, drowsy driving continues to be a major cause of car accidents, with more than 90,000 in 2017.17
In 2022, the National Highway Traffic Safety Administration estimates there will be 100,000 drowsy-driving accidents. Even a single night of sleeping only four to six hours can impact your ability to think clearly the next day.
Increased risk of neurological problems, ranging from depression to dementia and Alzheimer’s disease18— Your blood-brain barrier becomes more permeable with age, allowing more toxins to enter.19 This, in conjunction with reduced efficiency of the glymphatic system due to lack of sleep, allows for more rapid damage to occur in your brain and this deterioration is thought to play a significant role in the development of Alzheimer’s.
Increased risk of Type 2 diabetes — In one study,20 excessive daytime sleepiness increased the risk of Type 2 diabetes by 56%.
Decreased immune function — Research21 suggests deep sleep strengthens immunological memories of previously encountered pathogens. In this way, your immune system is able to mount a much faster and more effective response when an antigen is encountered a second time.
Increased risk of obesity
Increased risk of cancer — Tumors grew faster in laboratory animals with severe sleep dysfunctions.22 The primary mechanism thought to be responsible for this effect is disrupted melatonin production, a hormone with both antioxidant and anticancer activity.
Melatonin both inhibits the proliferation of cancer cells and triggers cancer cell apoptosis (self-destruction). It also interferes with the new blood supply tumors required for their rapid growth (angiogenesis).
Increased risk of high blood pressure, heart attacks and cardiovascular disease — As noted by Walker in the video above, “In the spring when we lose one hour of sleep, we see a subsequent 24% increase in heart attacks. In the fall, when we gain one hour of sleep, we see a 21% decrease in heart attacks. That is how fragile your body is with even the smallest perturbations of sleep …”
In his book, Walker also cites Japanese research showing male workers who average six hours of sleep per night or less are 400 to 500% more likely to suffer one or more cardiac arrests than those getting more than six hours of sleep each night.
Other research has demonstrated that women who get less than four hours of shut-eye per night increase their risk of dying from heart disease by 82%. Conversely, getting too much sleep increased their risk of heart disease by 95%, showing that it’s important to make sure you get enough sleep, but not too much.23
In another study,24 adults who slept less than five hours a night had 50% more coronary calcium, a sign of oncoming heart disease, than those who regularly got seven hours.
Increased risk of osteoporosis
Increased risk of pain and pain-related conditions such as fibromyalgia — In one study, poor or insufficient sleep was the strongest predictor for pain in adults over 50.25
Increased susceptibility to stomach ulcers
Impaired sexual function26,27
Impaired regulation of emotions and emotional perception — Your amygdala, one of your brain’s centerpiece regions for generating strong emotional reactions, including negative ones, becomes more reactive than usual when you’ve slept poorly or insufficiently, resulting in increased emotional intensity and volatility.28
Increased risk of depression and anxiety (including post-traumatic stress disorder), schizophrenia and suicide — According to a study in Neurologic Clinics, “there is growing experimental evidence that the relationship between psychiatric disorders and sleep is complex,” and can greatly influence bipolar disorder, anxiety disorder, schizophrenia and other psychological disorders.29
Premature aging by interfering with growth hormone production, normally released by your pituitary gland during deep sleep.
Increased risk of dying from any cause30— Compared to people without insomnia, the adjusted hazard ratio for all-cause mortality among those with chronic insomnia was 300% higher.
General Sleep Guidelines
So, how much sleep do you need to avoid this avalanche of ill effects? According to a scientific review of more than 300 studies published between 2004 and 2014 to ascertain how many hours of sleep most people need in order to maintain their health, a panel of experts came up with the following recommendations.31 Keep in mind that if you’re sick, injured or pregnant, you may need a bit more than normal.
|Age Group||Hours of sleep needed for health|
|Newborns (0 to 3 months)||14 to 17 hours|
|Infants (4 to 11 months)||12 to 15 hours|
|Toddlers (1 to 2 years)||11 to 14 hours|
|Preschoolers (3 to 5)||10 to 13 hours|
|School-age children (6 to 13)||9 to 11 hours|
|Teenagers (14 to 17)||8 to 10 hours|
|Adults (18 to 64)||7 to 9 hours|
|Seniors (65 and older)||7 to 8 hours|
How to Diagnose Sleep Deprivation
The following three factors, in combination, influence how restorative your sleep is:
- Duration — This is the number of hours you sleep. Sleep requirements are highly individual and can change from one day to the next, depending on factors like stress, physical exertion, illness and pregnancy, just to name a few. But, on average, most people need about eight hours of sleep per night.
- Timing — This is the habit of going to bed at approximately the same time each night. When you go to bed and wake up at the same times, your body becomes accustomed to the routine. This helps regulate your circadian clock so you fall asleep and stay asleep all night. Keep this routine, even on the weekends,32 because even if the duration of sleep is the same, when the timing of your sleep is shifted, it’s not going to be as restorative.
- Intensity — This has to do with the different stages your brain and body go through over the course of the night; the sequence of them, and how those stages are linked. Some medications will suppress certain phases of sleep, and certain conditions like sleep apnea will lead to fragmented sleep. With these scenarios, even if you’re sleeping for an adequate duration and have consistent timing, your sleep will not be as restorative.
One of the easiest ways to gauge whether you’ve slept enough is to assess your level of sleepiness the next day. For example, if you had the opportunity, would you be able to take a nap? Do you need caffeine to keep you going?
Answering yes to these two questions would indicate you need more and/or better sleep. Sometimes, however, signs of sleep deprivation can be less obvious. The late Nathaniel Kleitman, Ph.D., Professor Emeritus in physiology at the University of Chicago and a well-recognized pioneer in sleep research,33 developed a “sleep onset latency test,” to determine if you’re sleep-deprived. Here’s how it works:34
1. In the early afternoon, grab a spoon and head off to your darkened bedroom to take a nap. Place a metal tray on the floor beside your bed and hold the spoon over the tray as you attempt to fall asleep. Be sure to check the time as you lie down. (If you don’t have a spoon and metal tray handy, you can still take this test by setting an alarm for 15 minutes to see if you fall asleep before it goes off.)
2. When you fall asleep and the spoon crashes down onto the tray, waking you up, immediately check the time again and note how much time has passed.
a. If you fell asleep within five minutes, it means you’re severely sleep-deprived.
b. If it took you 10 minutes to fall asleep, you could still use more sleep.
c. If you managed to stay awake for 15 minutes or more before falling asleep, you’re probably well rested.
The Best Position for Sleep
In the video above, chiropractor and exercise physiologist Dr. Peter Martone discusses the benefits of adopting a neutral sleeping position. If you’re a side or stomach sleeper and find yourself frequently tossing and turning at night and/or wake up with aches and pains, your sleeping position may be a primary culprit. As noted by Martone, for sound, healthy sleep, you need to sleep on your back, with your neck and spine in a neutral position.
The key to achieving this is to prop a pillow under your neck, not your head, as this allows you to maintain a proper spinal curve. For a demonstration on how to use your pillow to support your neck rather than simply elevating your head, please see the video. In Martone’s experience, it takes an average of three to four months to convert from a side sleeper to a back sleeper, and even longer if you’re used to sleeping on your stomach.
Inclined Bed Therapy
Another posture-related change that might help improve your sleep is to raise the head of your bed so that you’re sleeping on an incline. Inclined bed therapy — which simply involves raising the head of your bed 6 to 8 inches so you’re sleeping on a 5-degree incline — may have a number of benefits, including:
Improving blood circulation
Improving glymphatic drainage from the brain
Improving immune system function
Improving respiratory function
Easing symptoms associated with Alzheimer’s, diabetes, glaucoma, migraines, multiple sclerosis, sleep apnea, acid reflux, edema, varicose veins and more
Please note that sleeping on an incline is not the same as sleeping on an adjustable bed that allows you to raise the head while the lower portion remains horizontal. Your body should be straight, but on an incline. You’re not looking to sleep in a sitting position where only your torso is lifted.
The alignment of your body is important, as you want your blood to circulate freely throughout your whole body and avoid stress on your hip joint. For tips on how to create an inclined bed, see InclinedBedTherapy.com.35 For example, you can build your own wooden bed frame, or use leg risers or full-length foam wedges.
Clean Up Your Sleep Hygiene to Optimize Your Health
There’s simply no doubt that sleep needs to be a priority in your life if you intend to live a long and healthy life. Anyone struggling with chronic disease — which is at least half of the American adult population — would be wise to take sleep seriously, as it can have a significant impact, not only contributing to the problem but also counteracting any other healthy lifestyle strategies you’re using to address it.
As a general guideline, seek to get right around eight hours of sleep every night. Anything under seven hours really starts to impact your health (if you’re an adult). For many, this means forgoing night-owl tendencies and getting to bed at a reasonable time. If you need to be up at 6 a.m., you have to have a lights-out deadline of 9:30 or 10 p.m., depending on how quickly you tend to fall asleep.
The good news is there are many ways to improve your odds of sleeping well, even if you’re currently struggling. Following are 50 of my top sleep tips. Go through this list and assess where your weaknesses might be, and start addressing the most obvious culprits. You may have to experiment a bit to find a combination that works best for you, but it’ll be well worth the effort.
50 Other Ways to Improve Your Sleep
1. Sleep in complete darkness, or as close to it as possible — Even the tiniest bit of light can disrupt your pineal gland’s production of melatonin and serotonin, thereby disrupting your sleep cycle. Even the tiniest glow from your clock radio has the potential to interfere with your sleep.
So, close your bedroom door, get rid of night lights and use blackout shades or thick drapes. If shades are out of your budget, use a well-fitting eye mask. Refrain from turning on any light at all during the night, even when getting up to go to the bathroom. If you absolutely have to have some sort of night light, use a red bulb.
2. Keep the temperature in your bedroom no higher than 70 degrees F — Studies show the optimal room temperature for sleep is between 60 to 68 degrees F.
Keeping your room cooler or hotter can lead to restless sleep. When you sleep, your body’s internal temperature drops to its lowest level, generally about four hours after you fall asleep. Scientists believe a cooler bedroom may therefore be most conducive to sleep, since it mimics your body’s natural temperature drop.
3. Sleep naked — Something as simple as sleeping naked may do the trick if you don’t want to crank down the temperature on your air conditioning. One of the established benefits of sleeping in the buff is improved sleep quality, in part by preventing overheating.
One study showed a surface skin temperature difference of as little as 0.08 degrees F (or 0.4 degrees C) led to sounder sleep.36,37,38 Studies have also found sleeping in the nude has several other health benefits, including improved metabolism and blood circulation.
4. Conquer sound pollution — Like temperature and light, sound can be a disruptive factor that’s keeping you awake. An inexpensive pair of earplugs can eliminate most noise.
5. Eliminate electric and electromagnetic fields (EMFs) in your bedroom — These can disrupt your pineal gland’s production of melatonin and serotonin, and are a significant contributor to mitochondrial damage and dysfunction, which is at the heart of virtually all chronic disease.
EMF exposure has also been linked to neuronal changes that affect memory and your ability to learn.39,40 EMFs harm your body’s mitochondria by producing excessive oxidative damage, so “marinating” in EMFs all night, every night, can cause or contribute to chronic ailments, including premature aging.
Ideally, shut down the electricity to your bedroom by pulling your circuit breaker before bed. If you have neighbors on the other side of the wall, floor or ceiling, consider installing a Faraday cage (copper- and/or silver-threaded fabric) around your bed. If you live in a high-rise and have neighbors beneath you, place the Faraday fabric on the floor beneath your bed as well. This may significantly improve your sleep quality.
However, even if you completely shut off the electricity in your bedroom 2 out of 3 people will still have electrified rooms. This is what happened to me, and when I used sophisticated body voltage measurements I was able to detect this.
This is a result of electrical fields (not electricity) transferred into your home by the electric utility and spreading in your home. This can be remediated with some effective types of paint shielding that is then grounded to form a Faraday cage, which stops the fields from entering your bedroom.
6. Shut down your Wi-Fi at night — Another really important step is to turn off your Wi-Fi at night. It would be best to hard wire your home so you have no Wi-Fi 24/7 in your home, but I realize many are unwilling or unable to take this step. It’s important to realize that the Wi-Fi in your home is nearly always more of a danger to you than what’s coming from outside your home.
You can confirm this by measuring the microwave signals with a meter, and seeing what your exposure is. The fact is, you don’t need Wi-Fi while..