Nearly 70 percent of adults throughout all developed nations fail to get the recommended eight hours of sleep each night.
This is a modern problem.
One hundred years ago, almost everyone was naturally getting seven to eight hours of sleep. Less than 2 percent of the United States population slept six hours or less a night.
Today, that number has risen to almost 30 percent.
Routinely sleeping six hours or less each night is associated with a 40 percent increased risk of developing cancer versus those who obtain seven hours of sleep or more (found in a European study with 24,000+ individuals).
The World Health Organization (WHO) has now declared a sleep loss epidemic throughout industrialized nations.
The link between sleep disturbance and cancer is so strong, the WHO has labeled shift-work as a probable carcinogen, placing it in the same risk class as ultraviolet radiation.
This silent epidemic is causing devastating damage to our health and almost no-one is talking about it.
Most of my life, I assumed six hours of sleep was plenty.
That was until I heard Dr. Matthew Walker speak on the Joe Rogan Experience in April of this year. During the two hour podcast (link provided above), Walker illustrated the importance of getting the recommended 7-9 hours of sleep each night and the risks in failing to do so.
After listening to the podcast, I got my hands on Walker’s book Why We Sleep: Unlocking the Power of Sleep and Dreams to get more information.Â
Below I have listed some of the risks associated with short sleep as well as what you can do to improve your sleep.
Negatively Affects Our Genes
The Surrey Sleep Research Center in England conducted a study where they took a group of healthy men and women and examined their gene expression after restricting the group to six hours of sleep a night for one week. The results were compared against the individuals’ baseline genetic profile when they were obtaining eight and a half hours of sleep a night per week.
After a week of slightly shorter sleep, 711 genes were disrupted in comparison to the genetic profile the individuals expressed in their baseline reading.
Half of the genes were abnormally increased by the loss of sleep and half of the genes were decreased or even completely shut down.
The genes that increased in activity were linked to chronic inflammation, cellular stress, and various factors that cause heart disease.
The genes that were slowed or shut off were related to maintaining a stable metabolism and immune response.
Lowers Testosterone
A research group at the University of Chicago took a group of lean, healthy young men in their mid-twenties and limited their sleep to five hours a night for one week. Their hormone levels were compared to their own baseline hormone reading where the individuals were fully rested.
The short sleep caused a significant drop in their testosterone levels by 10-15 percent. Normal aging is associated with decreased testosterone levels of 1-2 percent annually. The short sleep effectively aged the young men by ten to fifteen years.
Low testosterone in men reduces energy, effects concentration, lowers libido, and negatively impacts body composition.
Increases Our Likelihood of Cancer
Natural Killer cells (or NK cells) are a critical part of our immune system. They fend off infection and tumor formation, by inducing apoptosis, effectively killing the harmful cells.
The University of California conducted a study that revealed how one night of short sleep negatively impacts our cancer fighting NK cells.
One night of just four hours of sleep resulted in a 70 percent reduction of our NK cells circulating in our immune system compared to the amount present after sleeping eight hours a night.
That’s a significant decrease after just one night of poor sleep. Imagine months or even years of short changing our sleep. Our immune system is fighting a losing battle when our sleep is not dialed in.
Drowsy Driving Causes More Vehicular Accidents Than All Other Drugs Combined
1.2 million car accidents are caused by sleepiness each year in the United States.
This figure is from an extensive study conducted by the AAA Foundation which observed over 7,000 drivers during a two-year period.
Getting behind the wheel after a night of just three hours of sleep increases your odds of being in a car accident by 11.5 times.
An Australian study compared individuals with a blood alcohol content of .08 (legally drunk) against sleep deprived individuals. Each group took a concentration test to assess attention performance, specifically the number of mistakes.
Being awake for nineteen hours without sleep resulted in an impairment equivalent to those legally drunk.
Another reason why drowsy drivers cause more accidents than all other drugs: microsleeps.
Microsleeps are a momentary lapse in concentration, lasting just a few seconds, where the eyes are partially or fully shut. Not only does your vision go but all perceptions of reality are down. Most microsleeps go unnoticed, you have no awareness of the event, and you lose control of motor function.
It only takes a split second for a car accident to occur. Drowsy driving is objectively more dangerous than all other drug impairments because of the reaction time. In most cases, driving under the influence of drugs results in a delayed reaction to brake or make an elusive movement to dodge an accident. During a microsleep, we stop reacting entirely, meaning no braking and no other attempt to avoid the accident.
Reading this reminded me a road trip where I was driving the full 10 hours back to Pittsburgh after visiting friends in Boston for a weekend. Very little sleeping was done throughout that trip.
During the long drive home I experienced several microsleeps, but shook them off, thinking: I only shut my eyes for a second…
The last microsleep was significantly longer than the others, and the rumble strip on the side of the road woke me up. At this point my friend in the passenger seat asked if I was ok to finish the drive. My adrenaline was pumping after that wake up and I stubbornly finished the drive.
Thankfully, the rumble strip was the worst thing that happened and I didn’t crash into another car or end up in the embankment. I consider myself very fortunate and do everything I can to avoid repeating those driving conditions.
Contributes to the Obesity Epidemic
A study monitored healthy, lean individuals’ sense of hunger as well as their circulating levels of leptin (the satiety signaling hormone) and gherlin (the hunger inducing hormone).
The individual’s baseline readings were performed while they slept eight and a half hours a night for one week and compared them to the same individuals after sleeping only four to five hours a night for one week.
The individuals were given the same amount of food each day and activity levels were kept consistent.
Hunger pangs and increased appetite occurred by the second day of short sleeping.
The short sleep caused their leptin levels to decrease and increased their levels of gherlin. This caused the individuals to feel increased levels of hunger and decreased their feeling of being full.
It’s hard to stop eating when your body is demanding more food and has no chemical signal to say you’ve sufficiently eaten enough.
In another study, overweight individuals were put on a low-calorie diet for two weeks. There were two groups: one got eight and half hours in bed each night, the other only got five and a half hours in bed each night.
Both groups lost weight, but the source of the weight loss was very different.
The group with less sleep lost more than 70 percent of their weight from a healthy source: lean body mass (aka muscle) and less than 30 percent from fat.
The group with more sleep lost over 50 percent of their weight from fat, preserving more muscle mass, resulting in a healthier body composition.
Increases Cardiovascular Disease
Lack of sleep accelerates heart rate, increases blood pressure, and erodes the tissue of strained blood vessels, especially the coronary arteries.
“Adults forty five years or older who sleep fewer than six hours a night are 200 percent more likely to have a heart attack or stroke during their lifetime, as compared with those sleeping seven to eight hours a night.” – Matthew Walker Why We SleepÂ
The University of Chicago studied over 400 healthy, midlife adults with no existing heart disease or signs of atherosclerosis.
Individuals studied who slept five to six hours a night or less were 200 to 300 percent more likely to suffer calcification of the coronary arteries over the next five years compared to individuals who obtained seven to eight hours of sleep a night.
Heart health and sleep are undoubtedly connected. If these findings aren’t enough listen to this:
The Monday following daylights saving time in the spring, where we lose just one hour of sleep, heart attacks increase by 24 percent.
The Tuesday following daylights saving time in the fall, where we gain an hour of sleep, sees a 21 percent decrease in heart attacks.
Contributes to All Major Psychiatric Conditions
Including depression, anxiety, bipolar disorder and suicidality.
Dr. Allison Harvey at the University of California, Berkeley has been successfully using cognitive behavioral therapy (CBT-I), primarily used for insomnia patients, to help combat mental illness.
“By improving sleep quantity, quality, and regularity, Harvey and her team have systematically demonstrated the healing abilities of sleep for the minds of numerous psychiatric populations. She has intervened with the therapeutic sleep in conditions as diverse as depression, bipolar disorder, anxiety, and suicide, all to great affect. By regularizing and enhancing sleep, Harvey has stepped these patients back from the edge of crippling mental illness.” – Matthew Walker Why We Sleep
This is not to say all mental illnesses are caused by lack of sleep or cured by adequate sleep. But it’s imperative that we try to improve our mental health through natural methods.
Alcohol robs our body of REM Sleep
“Alcohol is one of the most powerful suppressors of REM sleep that we know of. When the body metabolizes alcohol it produces by-product chemicals called aldehydes and ketones. The aldehydes in particular will block the brain’s ability to generate REM sleep.” – Matthew Walker Why We Sleep
REM sleep is important because it helps energize the body and the brain, and is involved in the process of storing memories, learning, and balancing mood.
“Memories remain perilously vulnerable to any disruption of sleep (including that from alcohol) even up to three nights after learning, despite two full nights of natural sleep prior.” – Matthew Walker Why We Sleep
Meaning, you could be a college student studying material on Wednesday for an exam next Monday. Going out and drinking the Friday before your exam could interfere with your ability to retain the information you learned on Wednesday by disrupting your sleep and limiting your REM sleep.
Would’ve been nice knowing that during my years at the University of Pittsburgh.
These are just a few of the risks associated with poor sleep that I took note of during my reading. If you’re interested in learning more, please read Dr. Walker’s book.
What I Do For Better Sleep
- Physically active everyday (resistance training 5 days a week, 20-30 minute walk in the evening, physically demanding job)
- Turn temperature down to 65 degrees an hour before bed (your body needs to drop core temperature 2 – 3 degrees to successfully initiate sleep)
- Put my iPhone into ‘night mode’ during the evening (blue light blocker app for Android)
- Turn off bright lights in the evening, light candles instead
- Read for ~30 minutes before bed
- reading on an iPad vs reading a normal book can suppress melatonin by 50 percent, disrupts REM sleep, and can make falling asleep more difficult
- Avoid all screen time at least an hour before bed
- No caffeine in the afternoon
After reading Why We Sleep, I have done a better job prioritizing my sleep. On days I have to wake up at 4:00am I do my best to get at least 7 hours of time in bed. That’s better than the usual six hours of time in bed I was giving myself before.
My hours fluctuate at work, some days I start earlier than others, and some days I work late into the night (8:00pm). It’s difficult to keep a consistent sleep schedule (a tip heavily recommended in the book). But on most nights I try to get in bed before 10:00pm.
I’ve found giving myself seven hours in bed at minimum to be very beneficial.
On days I don’t have to wake up at 4:00am I almost always get eight hours of sleep.
In doing so, I have felt noticeably better.
We need to do a better job prioritizing our sleep as a whole.
Let your body heal itself and go through the natural, restorative process of a full night’s rest.
Talk again soon,
Shane
PS I have included 12 tips for better sleep from the NIH Medicine Plus Magazine, which was in the appendix of Dr. Walker’s book.
12 Tips for Better Sleep from the National Institutes of Health Medicine Plus the magazine.Â
1. Stick to a sleep schedule. Go to bed and wake up at the same time each day. As creatures of habit, people have a hard time adjusting to changes in sleep patterns. Sleeping later on weekends won’t fully make up for a lack of sleep during the week and will make it harder to wake up early on Monday morning.
2. Exercise is great, but not too late in the day. Try to exercise at least 30 minutes on most days but not later than 2-3 hours before your bedtime.
3. Avoid caffeine and nicotine before bed. Coffee, colas, certain teas, and chocolate contain the stimulant caffeine, and its effects can take as long as 8 hours to wear off fully. Therefore, a cup of coffee in the late afternoon can make it hard for you to fall asleep at night. Nicotine is also a stimulant, often causing smokers to sleep only very lightly. In addition, smokers often wake up too early in the morning because of nicotine withdrawal.
4. Avoid alcoholic drinks before bed. Having a “nightcap” or alcoholic beverage before sleep may help you relax, but heavy use robs you of deep sleep and REM sleep, keeping you in the lighter stages of sleep. Heavy alcohol ingestion also may contribute to breathing impairment at night. You also tend to wake up in the middle of the night when the effects of the alcohol have worn off.
5. Avoid large meals and beverages late at night. A light snack is okay, but a large meal can cause indigestion that interferes with sleep. Drinking too many fluids at night can cause frequent awakenings to urinate.
If possible, avoid medicines that delay or disrupt your sleep. Some commonly prescribed heart, blood pressure, or asthma medications, as well as some over-the-counter and herbal remedies for coughs, colds, or allergies, can disrupt sleep patterns. If you have trouble sleeping, talk to your healthcare provider or pharmacist to see whether any drugs you’re taking might be contributing to your insomnia and ask whether they can be taken at other times during the day or early in the evening.6. Don’t take naps after 3 p.m. Naps can help make up for lost sleep, but late afternoon naps can make it harder to fall asleep at night.
7. Relax before bed. Don’t overschedule your day so that no time is left for unwinding. A relaxing activity, such as reading or listening to music, should be part of your bedtime ritual.
8. Take a hot bath before bed. The drop in body temperature after getting out of the bath may help you feel sleepy, and the bath can help you relax and slow down so you’re more ready to sleep.
9. Have a good sleeping environment. Get rid of anything in your bedroom that might distract you from sleep, such as noises, bright lights, an uncomfortable bed, or warm temperatures. You sleep better if the temperature in the room is kept cool. A TV, cell phone, or computer in the bedroom can be a distraction and deprive you of needed sleep. Having a comfortable mattress and pillow can help promote a good night’s sleep. Individuals who have insomnia often watch the clock. Turn the clock’s face out of view so you don’t worry about the time while trying to fall asleep.
10. Have the right sunlight exposure. Daylight is key to regulating daily sleep patterns. Try to get outside in natural sunlight for at least 30 minutes each day. If possible, wake up with the sun or use bright room lights in the morning. Sleep experts recommend that, if you have problems falling asleep, you should get an hour of exposure to morning sunlight and turn down the lights before bedtime.
11. Don’t lie in bed awake. If you find yourself still awake after staying in bed for more than 30 minutes or if you are starting to feel anxious or worried, get up and do some relaxing activity until you feel sleepy. The anxiety of not being able to sleep can make it harder to fall asleep.
12. See a health professional if you continue to have trouble sleeping. If you consistently find it difficult to fall or stay asleep and/or feel tired or not well rested during the day despite spending enough time in bed at night, you may have a sleep disorder. Your family healthcare provider or a sleep specialist should be able to help you, and it is important to rule out other health or emotional problems that may be disturbing your sleep.