Sleep Important for Your Memory and Cognitive Health
Doesn't this look relaxing?"
Rest and relaxation, coupled with exercise, help to rejuvenate your mind. Don't short change yourself on sleep. Just try your Memcheck exercises while very tired...this will tell you need your rest.
Sleepy Nation: As millions suffer sleep debt, experts say it's time to pay up
By STEVE EDWARDS - Anchorage Daily News
"Blessings on him who first invented sleep. It covers a man all over, thoughts and all, like a cloak. "It is meat for the hungry, drink for the thirsty, heat for the cold and cold for the hot. It makes the shepherd equal to the monarch, and the fool to the wise."
- 'Don Quixote' by Saavedra M. de Cervantes
Those were the words of Sancho Panza as he traveled with Don Quixote. Today it appears many curse sleep instead of bless it. Millions of people worldwide fail to get the nightly sleep they need. If the body demands eight hours of sleep, people give it seven or six or five.
The American Academy of Sleep Medicine says there are at least 84 sleep disorders. More than 100 million Americans fail to get a good night's sleep; some studies indicate that 35 percent of the world's population suffers from insomnia.
Sleep isn't a luxury, but many people see it that way. "Sleep is very, very important," said Dr. Anne Morris of Providence Alaska Medical Center's Sleep Disorders Center. "The quality of sleep can determine the safety and the quality of our waking lives."
While many people may recall their parents' or grandparents' admonition of "Early to bed, early to rise," few really understand sleep.
And that includes the medical community. "No one really knows why we sleep or why different species require different amounts of sleep," said Dr. Norman Wilder, vice president of medical affairs for Alaska Regional Hospital and a sleep expert. "Why can't you just sit in your recliner chair and relax? No one knows.
"What is it about the brain that it shuts off and puts the body to sleep? We don't have answers, but we do know that it must happen."
While scientists and doctors continue researching sleep, they understand its value. Throughout a night of sleep, the body goes through a variety of stages in cycles that last from 90 to 120 minutes. Those stages include light sleep, deep sleep and REM, or rapid-eye movement, sleep. Generally, intense dreaming occurs during REM sleep due to increased cerebral activity.
"There is a rhythmic shifting, from lighter stages to deeper stages, all night long," said Jerry Trodden, clinical manager of Providence's Sleep Disorders Center. "The body, mind and intellect all need restoration."
Sleep provides the body the time it needs to rest and repair, Morris said. During deep sleep, also called delta sleep, the body produces growth hormones, she said. While that's obviously critical for children, she said adults can't cut short their deep sleep.
The body's immune system is working at its maximum capacity, "checking for anything that might go amiss," she said. It's also the time tissues undergo repair and blood pressure and heart rate are lower, allowing the circulatory system to rest.
Many researchers say the brain processes information during sleep, especially during REM stages. Some say short-term memory is converted to long-term memory during this stage.
"Our brain is more active during dream-sleep cycles than it is while we are awake," Morris said. "It has a 40 percent higher blood flow."
So the body and mind are busy during sleep. In addition to feeling refreshed after a good night's sleep, the body is healthier.
So what happens if we rob ourselves of needed sleep? Wilder cites a clinical study done with rats as an example. He said scientists purposefully kept rats from sleep. After a short amount of sleep deprivation, the rats died.
"There is no reason to believe that extreme sleep deprivation wouldn't have extreme adverse affects on (people)," he said. “If we were physically kept from sleep, we would probably die."
While few are likely to fall over and die like rats, sleep experts say vehicle and occupational accidents are frequently due to sleep deprivation. The U.S. National Highway Traffic Safety Administration cites drowsiness as a factor in 100,000 police-reported crashes annually, involving 76,000 injuries and 1,500 deaths.
"In the past, when someone was driving drunk, people made jokes about it," Morris said. "Now it's illegal and considered morally reprehensible. "Driving sleepy is equally reprehensible because it's equally preventable." She said when the brain is tired enough, it will automatically go into "microsleep" mode. It will simply shut down for a second or a few seconds. Most people notice it when the head drops down and then snaps back as the person wakes up.
There are other health concerns. Recent studies suggest that chronic sleep loss is a risk factor for diabetes. Morris said a study conducted in Chicago involved healthy young adults. They were cut to five hours of sleep nightly for a few weeks. The participants were subject to more colds, viral infections and were pushed into a higher risk of diabetes.
Additionally, with sleep loss there is frequently increased hunger and appetite. So, sleep loss could be connected with weight gain and obesity, another epidemic in the United States.
There are even larger societal concerns. Morris said disasters involving the Exxon Valdez, the Chernobyl nuclear facility, the Challenger space shuttle and the Three Mile Island nuclear power plant were all partially attributable to lack of sleep.
While there are dozens of sleep disorders, the most common is insomnia. Most people have suffered occasional insomnia, which is generally considered to be trouble falling asleep or staying asleep. It is often grouped into two categories, transient and persistent insomnia.
Transient insomnia lasts a few days to a month. It is frequently brought on by excitement or stress. Travel, especially across several time zones, can also bring on transient insomnia.
Chronic or persistent insomnia can be caused by a number of factors. Those include lifestyle, psychological factors, environmental factors and physical and psychiatric illness.
Another common cause of sleeplessness is snoring. While the non-snorer may be kept awake by the noise, the snorer may be suffering from obstructive sleep apnea. People with OSA suffer brief periods of asphyxia during sleep, followed by periods of hyperventilation.
"The patients we see the most have interrupted breathing during sleep," Trodden said. "Mild snoring is just positional; obstructive sleep apnea is different. It causes pauses in breathing, then the person wakes up. The person doesn't spend much time in restorative sleep.
"That's something that needs to be corrected and can be corrected."
WHAT CAN WE DO?
Quite simply, get enough sleep. "We have to budget more time for sleep," Trodden said. "A lot of people regard it as a waste of time. The body and mind must restore themselves if we are to go forward in a healthy way.
"It is a necessary part of life." Of course, it's not always easy. At times, it's even difficult to pinpoint how much sleep is the right amount of sleep. Wilder said study after study supports the idea of eight hours of sleep for adults. Children need more sleep than adults. Information from the American Academy of Sleep Medicine indicates that 85 percent of today’s teens are not getting enough sleep. In fact, 26 percent are getting six or fewer hours of sleep on school nights.
When people get only six to seven hours of sleep a night, they begin accumulating sleep debt. By the end of the workweek or school week, a person could have accumulated five to 10 hours or more of debt. That will usually result in sleeping in on weekend mornings.
"If you always need an alarm clock to wake up; if you can’t get started in the morning without a pot of coffee; if you sleep in on weekends; if you always nap a lot, that suggests you are carrying a lot of sleep debt," Morris said. "While we might be able to make it up spending the weekends sleeping, it would be better if we just went to bed earlier."
Following a program of sleep hygiene can help overcome sleep problems. Sleep hygiene refers to good lifestyle and dietary habits that encourage sleep. It includes following a consistent sleep-wake pattern; avoiding caffeine, nicotine and alcohol before bedtime; getting regular exercise; and using the bedroom only for sleep and sex.
Morris, who said the Providence clinic sees up to 250 patients a month, said there is good news about sleep disorders. "The great majority of sleep disorders are recognizable and highly treatable," she said. "People need to get seen and get a correct diagnosis."
Habits and behaviors that have a positive effect on sleep are classified as sleep hygiene. Suggestions include:
- WAY OF LIFE: Get regular exercise at the right time of day. Many doctors encourage daily exercise, but don't work out within four hours of bedtime.
- KEEP EXCITEMENT DOWN: Exciting movies, television or reading can have a stimulating effect. Before going to bed, it could be better to listen to soothing music, read something relaxing or take a warm bath.
- FOOD AND DRINK: Sometimes a light snack before bedtime can help, but do not eat a heavy meal. Also avoid alcohol, caffeine and nicotine before bedtime.
- IN THE BEDROOM: Minimize light, noise and temperature extremes in the bedroom. Use the bedroom only for sleep and sex; do not watch television, eat or study in bed.
- HINTS: If you are unable to fall asleep or stay asleep, leave your bedroom and engage in a quiet activity elsewhere. Return to the bedroom only when you are sleepy. Avoid clock watching; it can lead to frustration, which makes it more difficult to fall asleep. Maintain regular rise times and sleep times, even on days off and weekends.