40 Facts About Sleep

40 FACTS ABOUT SLEEP YO U PROBABLY DIDN'T KNOW... (OR WERE TOO TIRED TO THINK ABOUT) What really strikes me: "Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol level of 0.05%." -The record for the longest period without sleep is 18 days, 21 hours, 40 minutes during a rocking chair marathon. The record holder reported hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses. - It's impossible to tell if someone is really awake without close medical supervision. People can take cat naps with their eyes open without even being aware of it. - Anything less than five minutes to fall asleep at night means you're sleep deprived. The ideal is between 10 and 15 minutes, meaning you're still tired enough to sleep deeply, but not so exhausted you feel sleepy by day. - A new baby typically results in 400-750 hours lost sleep for parents in the first year - One of the best predictors of insomnia later in life is the development of bad habits from having sleep disturbed by young children. - The continuous brain recordings that led to the discovery of REM (rapid eye-movement) sleep were not done until 1953, partly because the scientists involved were concerned about wasting paper. - REM sleep occurs in bursts totalling about 2 hours a night, usually beginning about 90 minutes after falling asleep. - Dreams, once thought to occur only during REM sleep, also occur (but to a lesser extent) in non-REM sleep phases. It's possible there may not be a single moment of our sleep when we are actually dreamless. - REM dreams are characterised by bizarre plots, but non-REM dreams are repetitive and thought-like, with little imagery - obsessively returning to a suspicion you left your mobile phone somewhere, for example. - Certain types of eye movements during REM sleep correspond to specific movements in dreams, suggesting at least part of the dreaming process is analagous to watching a film - No-one knows for sure if other species dream but some do have sleep cycles similar to humans. - Elephants sleep standing up during non-REM sleep, but lie down for REM sleep. - Some scientists believe we dream to fix experiences in long-term memory, that is, we dream about things worth remembering. Others reckon we dream about things worth forgetting - to eliminate overlapping memories that would otherwise clog up our brains. - Dreams may not serve any purpose at all but be merely a meaningless byproduct of two evolutionary adaptations - sleep and consciousness. - REM sleep may help developing brains mature. Premature babies have 75 per cent REM sleep, 10 per cent more than full-term bubs. Similarly, a newborn kitten puppy rat or hampster experiences only REM sleep, while a newborn guinea pig (which is much more developed at birth) has almost no REM sleep at all. - Scientists have not been able to explain a 1998 study showing a bright light shone on the backs of human knees can reset the brain's sleep-wake clock. - British Ministry of Defence researchers have been able to reset soldiers' body clocks so they can go without sleep for up to 36 hrs. Tiny optical fibres embedded in special spectacles project a ring of bright white light (with a spectrum identical to a sunrise) around the edge of soldiers' retinas, fooling them into thinking they have just woken up. The system was first used on US pilots during the bombing of Kosovo. - Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol-level of 0.05%. - The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have all been attributed to human errors in which sleep-deprivation played a role. - The NRMA estimates fatigue is involved in one in 6 fatal road accidents. - Exposure to noise at night can suppress immune function even if the sleeper doesn’t wake. Unfamiliar noise, and noise during the first and last two hours of sleep, has the greatest disruptive effect on the sleep cycle. - The "natural alarm clock" which enables some people to wake up more or less when they want to is caused by a burst of the stress hormone adrenocorticotropin. Researchers say this reflects an unconscious anticipation of the stress of waking up. - Some sleeping tablets, such as barbiturates suppress REM sleep, which can be harmful over a long period. - In insomnia following bereavement, sleeping pills can disrupt grieving. - Tiny luminous rays from a digital alarm clock can be enough to disrupt the sleep cycle even if you do not fully wake. The light turns off a "neural switch" in the brain, causing levels of a key sleep chemical to decline within minutes. - To drop off we must cool off; body temperature and the brain's sleep-wake cycle are closely linked. That's why hot summer nights can cause a restless sleep. The blood flow mechanism that transfers core body heat to the skin works best between 18 and 30 degrees. But later in life, the comfort zone shrinks to between 23 and 25 degrees - one reason why older people have more sleep disorders. - A night on the grog will help you get to sleep but it will be a light slumber and you won't dream much. - After five nights of partial sleep deprivation, three drinks will have the same effect on your body as six would when you've slept enough. - Humans sleep on average around three hours less than other primates like chimps, rhesus monkeys, squirrel monkeys and baboons, all of whom sleep for 10 hours. - Ducks at risk of attack by predators are able to balance the need for sleep and survival, keeping one half of the brain awake while the other slips into sleep mode. - Ten per cent of snorers have sleep apnoea, a disorder which causes sufferers to stop breathing up to 300 times a night and significantly increases the risk of suffering a heart attack or stroke. - Snoring occurs only in non-REM sleep - Teenagers need as much sleep as small children (about 10 hrs) while those over 65 need the least of all (about six hours). For the average adult aged 25-55, eight hours is considered optimal - Some studies suggest women need up to an hour's extra sleep a night compared to men, and not getting it may be one reason women are much more susceptible to depression than men. - Feeling tired can feel normal after a short time. Those deliberately deprived of sleep for research initially noticed greatly the effects on their alertness, mood and physical performance, but the awareness dropped off after the first few days. - Diaries from the pre-electric-light-globe Victorian era show adults slept nine to 10 hours a night with periods of rest changing with the seasons in line with sunrise and sunsets. - Most of what we know about sleep we've learned in the past 25 years. - As a group, 18 to 24 year-olds deprived of sleep suffer more from impaired performance than older adults. - Experts say one of the most alluring sleep distractions is the 24-hour accessibility of the internet. - The extra-hour of sleep received when clocks are put back at the start of daylight in Canada has been found to coincide with a fall in the number of road accidents.

Lost Sleep Can Lead to Weight Gain

By TARA PARKER-POPE

The best path to a healthy weight may be a good night’s sleep.

For years researchers have known that adults who sleep less than five or six hours a night are at higher risk of being overweight. Among children, sleeping less than 10 hours a night is associated with weight gain.

Now a fascinating new study suggests that the link may be even more insidious than previously thought. Losing just a few hours of sleep a few nights in a row can lead to almost immediate weight gain.

Sleep researchers from the University of Colorado recruited 16 healthy men and women for a two-week experiment tracking sleep, metabolism and eating habits. Nothing was left to chance: the subjects stayed in a special room that allowed researchers to track their metabolism by measuring the amount of oxygen they used and carbon dioxide they produced. Every bite of food was recorded, and strict sleep schedules were imposed.

The goal was to determine how inadequate sleep over just one week — similar to what might occur when students cram for exams or when office workers stay up late to meet a looming deadline — affects a person’s weight, behavior and physiology.

During the first week of the study, half the people were allowed to sleep nine hours a night while the other half stayed up until about midnight and then could sleep up to five hours. Everyone was given unlimited access to food. In the second week, the nine-hour sleepers were then restricted to five hours of sleep a night, while the sleep-deprived participants were allowed an extra four hours.

Notably, the researchers found that staying up late and getting just five hours of sleep increased a person’s metabolism. Sleep-deprived participants actually burned an extra 111 calories a day, according to the findings published last week in The Proceedings of the National Academy of Sciences.

But even though we burn more calories when we stay awake, losing sleep is not a good way to lose weight. The light sleepers ended up eating far more than those who got nine hours of sleep, and by the end of the first week the sleep-deprived subjects had gained an average of about two pounds.

During the second week, members of the group that had originally slept nine hours also gained weight when they were restricted to just five hours. And the other group began to lose some (but not all) of the weight gained in that first sleep-deprived week.

Kenneth Wrightdirector of the university’s sleep and chronobiology laboratory, said part of the change was behavioral. Staying up late and skimping on sleep led to not only more eating, but a shift in the type of foods a person consumed.

“We found that when people weren’t getting enough sleep they overatecarbohydrates,” he said. “They ate more food, and when they ate food also changed. They ate a smaller breakfast and they ate a lot more after dinner.”

In fact, sleep-deprived eaters ended up eating more calories during after-dinner snacking than in any other meal during the day. Over all, people consumed 6 percent more calories when they got too little sleep. Once they started sleeping more, they began eating more healthfully, consuming fewer carbohydrates and fats. Dr. Wright noted that the effect of sleep deprivation on weight would likely be similar in the real world although it might not be as pronounced as in the controlled environment. The researchers found that insufficient sleep changed the timing of a person’s internal clock, and that in turn appeared to influence the changes in eating habits. “They were awake three hours before their internal nighttime had ended,” Dr. Wright said. “Being awakened during their biological night is probably why they ate smaller breakfasts.”

The effect was similar to the jet lag that occurs when a person travels from California to New York.

Last fall, The Annals of Internal Medicine reported on a study by University of Chicago researchers, who found that lack of sleep alters the biology of fat cells. In the small study — just seven healthy volunteers — the researchers tracked the changes that occurred when subjects moved from 8.5 hours of sleep to just 4.5 hours. After four nights of less sleep, their fat cells were less sensitive to insulin, a metabolic change associated with both diabetesand obesity.

“Metabolically, lack of sleep aged fat cells about 20 years,” said Matthew Brady, an associate professor of medicine at the University of Chicago and the senior author on the study.

“These subjects were in their low 20s but it’s as if they were now middle-aged in terms of their response. We were surprised how profound the effects were.”

Both Drs. Wright and Brady noted that because their studies lasted only days, it was not clear how long-term sleep deprivation affects weight, and whether the body adjusts to less sleep.

Dr. Brady said that while better sleep would not solve the obesity problem, paying more attention to sleep habits could help individuals better manage their weight.

In the future he hopes to study whether a focus on better sleep could improve the health of people in middle age who are overweight or prediabetic.

“Telling someone they need to sleep more as a way to improve their metabolic health, we think would be more palatable,” said Dr. Brady. “We think sleep is very underappreciated.”

A version of this article appeared in print on 03/19/2013, on page D4 of the NewYork edition with the headline: Lost Sleep Can Lead to Weight Gain

What's the Best Pillow?

We have so many customers who are desperate to find a good pillow, it seems logical to discuss how to do so.

In our previous post  “Is a Firm Mattress Better? “ we sought to educate the customer as to how his/her weight, build, and sleeping positions determine, to a very large degree, what firmness of mattress is going to hold the body the most properly. 

As a quick reminder: In a properly supportive mattress, one that keeps your body in a neutral alignment, the spinal column will be supported evenly.  

Meaning that in a side sleeping position, the shoulders and hips should compress the mattress just enough to get support through the midsection and maintain a straight alignment in the spinal column.

In a back sleeping position, the seat should compress just enough of the mattress so the low back concavity gets supported and kept in a neutral position.

What about pillows?

The right pillow for each person depends, again, on build and sleeping positions, but there’s one more thing to take into consideration: the firmness of your mattress.

Why is that?

The deeper your body gets into the surface of your mattress, the less space needs to be filled under the neck to keep it in a healthy position.

A well-fitting pillow will help keep the neck and head in a healthy neutral alignment.

Stand up in a relaxed position and look forward.  Take a look at the space between your chest and your neck.  That’s the same amount of space you need while sleeping in order promote the healthiest position, which allows optimum oxygen flow. Also, this position will allow the neck muscles to relax properly while sleeping.

Imagine finding the perfect pillow to go along with your mattress. Everything is in perfect alignment; you can breathe easily. There’s no stress in the neck. You wake up without pain. You have set yourself up in a beautiful, healthy neutrality while you sleep!

Now take this pillow with you on vacation, where the bed is far softer than yours at home.  Your body sinks in more deeply to the vacation bed. Now, all of a sudden, the pillow that works so beautifully at home is too big! Your head is pitched up at an angle, causing both neck stress and breathing issues. Not good.

Keeping in mind how the mattress itself plays such an important role in finding the correct pillow, let’s now talk about sleeping positions.

Back Sleepers: Generally need lower pillows. Go too tall with a pillow, and your head will be pitched up at an angle.  This is terrible positioning for a couple of reasons. Firstly, it puts a bend in the airway, which impedes oxygen flow, which can cause snoring. Secondly, the neck will not rest in a healthy position. Neck pain upon awakening will generally occur.

Side Sleepers:  Tend to have more problems with finding a pillow that corrects their positioning from the neck up.  There needs to be enough lift under the neck to fill up the area between neck and shoulders, but enough softness under the head itself to allow it to drop into a neutral position.

If the pillow is too short, your head will angle downwards.

If the pillow is too tall, the opposite happens: the head angles upwards. Ultimately, the neck stress and lack of proper oxygenation will happen in both instances.

Stomach Sleepers: Generally don’t need a pillow.  But there are many different “stomach sleeping” positions.

For those who sleep truly flat on their bellies; think about the placement of the head while you’re in that position. In order to breathe, you must turn your head severely to one side. This is wreaking havoc on the neck. Torsion of the neck in this position stresses the musculature and can force the cervical vertebrae out of correct position. Our advice is: Do everything within your power to change your sleeping position! The neck is a delicate region and just cannot withstand such stress and maintain good health.

For those who do more of a “belly crawl”; more of a side/belly combo, usually with one leg drawn up. These sleepers like to angle the pillow in order to hug a portion of it. In these instances, look for a pillow that keeps the head as neutral as possible with the spinal column. If the head is pitched upward or downward, the problems with neck pain and breathing will occur.

There you have it. The best pillow for you is dictated by your body, your sleeping positions, and your bed.

One more thing to think about: most people sleep in both side and back positions. Ideally, your best pillow will be able to keep your head and neck properly aligned in both positions.

This is why we have 17 different sizes of Oxygen Pillow-to accommodate the sleepers’ varying positions while still maintaining neutrality.  You can have proper alignment, more open airways, and wonderful comfort all night long.

Snoring Linked to Cancer

by Cindy Kuzma May 25, 2012, 05:00 am EST

Don’t get mad when your girlfriend kicks you out of bed for snoring. Get help—it might save your life.

Snoring is the main symptom of sleep apnea, a disorder in which your breathing becomes shallow or even stops for a while during the night. People with severe sleep apnea are almost five times as likely to die of cancer than those who breathe easy while they sleep, according to a new study presented last week at the American Thoracic Society conference. The study, which tracked 1,500 people for 22 years, found that mild or moderate snoring also increases your risk of cancer death. (To live to see your great-grandkids, follow these 50 Tips to Live Longer.)

Sleep apnea reduces the oxygen level in your blood; to avoid suffocating, tumors grow new blood vessels, says study author F. Javier Nieto, M.P.H., M.D., Ph.D., of the University of Wisconsin-Madison School of Medicine and Public Health. These extra veins and arteries help existing tumors grow faster and give cancer cells more opportunities to spread through your bloodstream to new parts of your body.

It’s not yet clear whether sleep apnea increases your risk of getting cancer or just worsens existing cases, and more research is needed to confirm the results. But snoring is cause for concern either way—leading to accidents, depression, high blood pressure, and heart disease. If you snore and are sleepy during the day, check with your doctor, especially if you’re carrying a few extra pounds (they increase your sleep apnea risk). Other signs of sleep apnea include grumpiness, forgetfulness, and headaches that are hard to shake. (If you’re battling other aches and pains, click her for The Real Reasons Why Your Body Hurts.)

http://news.menshealth.com/snoring-cancer/2012/05/25/

Sleep deprivation has genetic consequences, study finds

Researchers say a lack of sleep affects the function of genes related to stress and cell renewal, possibly contributing to poor health.

By Eryn Brown, Los Angeles Times

March 1, 2013, 11:26 a.m.

Doctors know that being chronically sleep-deprived can be hazardous to your health. Night-shift workers, college crammers and all the rest of us who get less than our fair share of zzz's are more likely to be obese and to suffer cardiovascular woes than people who get a consistent, healthful eight hours.

Now scientists have some new clues about how lack of sleep translates into disease.

After subjecting 26 volunteers to seven nights of insufficient shut-eye followed by a marathon all-nighter, researchers detected changes in the way hundreds of genes were expressed in their bodies. Some genes, including damage-inducing ones involved in stress reactions, were amplified. Others, including many that nurture and renew cells and tissues, were turned down.

"It's possible to see how that contributes to poor health," said Colin Smith, a genomics researcher at the University of Surrey in England and one of the senior authors of a report detailing the findings this week in the journal Proceedings of the National Academy of Sciences.

Scientists have long puzzled over the purpose of sleep. For years they focused on how it influenced the brain, said Derk-Jan Dijk, a sleep and circadian rhythm researcher at the same institution and the study's other senior author.

But epidemiologists noticed that people who work early in the morning or late at night — or who lack sleep in general — have higher rates of diabetes, stroke and high blood pressure, among other ailments. And biologists have discovered that people who get poor sleep produce more of the stress hormone cortisol and the appetite stimulating hormone ghrelin, among other biochemical changes.

"It used to be thought that sleep was by the brain, of the brain, for the brain," said Dr. Charles Czeisler, a Harvard Medical School researcher who is well-known for his examinations of how poor sleep affects people in a variety of everyday settings. "Now it's recognized that it plays an important role in bodily functions."

To learn more about the biological mechanisms at work, Dijk, Smith and colleagues asked their study volunteers to complete two 12-day-long evaluations.

In one test condition, the subjects — all healthy adults who did not suffer from sleep disorders — were allowed to stay in bed for 10 hours on seven consecutive nights. Brain wave scans showed that they slept for an average of 8.5 hours each night, an amount considered sufficient.

In the other test condition, subjects were allowed to stay in bed just six hours a night for seven nights, and they got an average of only 5.7 hours of sleep.

At the end of each week of controlled sleep, the researchers kept subjects awake for 39 to 41 hours, drawing blood every three hours for a total of 10 samples.

Then they analyzed cells in the blood, looking at changes in RNA — the molecule that carries out DNA instructions, creating the proteins that drive processes in the body.

They found that losing sleep changed rhythmic patterns in the way genes turn on and off, disrupting the genes' circadian clock.

Also, overall, 711 genes were expressed differently when people were sleep-deprived: 444 were turned down, and 267 were amped up.

Further analysis revealed that genes involved in inflammation, immunity and protein damage were activated, suggesting that tissue harm was occurring after sleep deprivation. Many of the down-regulated genes, in contrast, were involved in producing new proteins, cells and tissues. The balanced process of tissue renewal seemed to be disrupted by insufficient sleep.

Dijk and Smith said they found it striking that the changes were so readily apparent after just one week.

According to the U.S. Centers for Disease Control and Prevention, 30% of civilian adults in the U.S. say they get six or fewer hours of sleep. That suggests that millions of people might be sustaining damage to their bodies.

Scientists who were not involved the study praised its careful design and said that being able to use blood to assess the molecular effects of sleep deprivation represented a promising advance for the field.

In the past, many studies of the biological consequences of sleep restriction were conducted in laboratory animals like mice, with scientists examining gene expression in tissues from the brain or the liver. For obvious reasons, that's not feasible with people.

But the ability to use a simple blood test to "tell what time of day" it is in a person's body could help doctors deal with their sleep-deprived patients, said Czeisler, who wasn't part of the British research team.

Today, doctors must rely on a patient's self-assessment of how tired he or she feels. But caffeine "gums up the signal" that tells the brain when it needs more sleep, fooling people into thinking that they're getting plenty of rest, Czeisler said.

"This could be an early warning system" that could let doctors know a patient is at risk for ills related to sleep loss, he said.