Sleep: It Does a Lot More than you Think

Biology 103
2002 Second Paper
On Serendip

Sleep: It Does a Lot More than you Think

Meredith Stoll

Your doctor and your mother always recommended getting at least eight hours a sleep a night. Everyone knows without the proper amount of sleep, the mind will be groggy the next day, and as a result, many more mistakes will be made, meaning that you should get a full night's rest before taking a test, or a little nap before a long drive in a car. But scientists are beginning to realize that sleep is not just a mental recharger, but also important for the body as well. When a person sleeps, the body and mind are working just as hard as when the person is awake, correcting chemical imbalances, assuring proper blood sugar levels for the next day, and maintaining the memory(1). Before electricity, people would generally go to sleep when the sunset and rise when it rose, assuring that they got enough sleep to maintain a healthy mind and body. But in a highly industrialized nation where the light bulb has expanded the working day into 24 not 12 hours, it is becoming apparent that more and more people are sleep deprived. And with that deprivation, more and more scientists are realizing, comes not only a mental deficiency, but also a physical one.

It is not quite clear what physically happens in the body when one sleeps. Although scientists can read brainwaves on an EEG, they are not sure when exactly the brain is doing, although they acknowledge that dreaming is a large part of it. When the body is sleeping, the brain goes through four different stages, called the REM (Rapid Eye Movement) sleep cycles. At different stages, the brain is active in different ways, as seen on EEG brainwave readers. In the first stages of sleeping, the body begins to relax, the heart rate slows, and people often feel as though they are falling or otherwise weightless. As the body slips into the second and third stages of the cycle, it is very apparent that the brain is not acting in the same way (i.e. emitting the same brain waves) as when the body is awake, but nevertheless the activity is still there. This is where your body performs daily maintenance and healing, and where deep restful sleep occurs"(2).

If the body does not go through enough REM cycles, it cannot fully heal itself, making the body act sluggish the next day. Some signs of sleep deprivation include reduced energy, greater difficulty concentrating, diminished mood, and greater risk for accidents, including fall-asleep crashes. Work performance and relationships can suffer too. And pain may be intensified by the physical and mental consequences of lack of sleep(3).Thus, staying up all night to study for that test or finish that presentation actually is more detrimental than originally thought. Even everyday tasks, such as driving a car or even answering the phone are affected by lack of sleep, making those people who work under such conditions a danger to themselves and others. The memory is also affected. During sleep, the brain may recharge its energy stores and shift the day's information that has been stored in temporary memory to regions of the brain associated with long-term memory(3).

Scientists are realizing more and more the physical effects of lack of sleep. Sleep deprivation also weakens the immune system, preventing the body from being able to ward of infections and viruses. But, it also affects the chemical balances within the body. Men, who are normally healthy, start to show affects of aging after only a few nights of less than adequate sleep. In a study done at the University of Chicago, Dr. Eve Van Cauter found that, "after four hours of sleep for six consecutive nights, healthy young men had blood test results that nearly matched those of diabetics. Their ability to process blood sugar was reduced by 30 percent, they had a huge drop in their insulin response, and they had elevated levels of a stress hormone called cortisol, which can lead to hypertension and memory impairment"(4). Such physical effects were unheard of before this study, and as a result, scientists are now looking into connections with lack of sleep and obesity.

One such consideration is how the body regulates sleep itself. The body is monitored by the called the Circadian Rhythm, a natural internal clock that resets itself every 24-hours(5). This clock releases different chemicals in the body, depending on if it thinks the body needs to sleep or be awake. It is most easily set by direct, or as scientist are now discovering, indirect light. It is a common fact that it is easier to sleep with a light on than without, and scientists are now realizing that is because of the Circadian Rhythm. What this means is that every time you turn on a light, you are resetting the Rhythm just a little, making the individual cells within the body not release chemicals or produce the necessary proteins at the right time. Resetting the Rhythm also means that the body is working overtime, making it more out of balance and less efficient. Thus, not only are the necessary chemicals imbalanced, but the body will age faster as it is forced to work for longer and longer hours without being able to restore itself.

This discovery, in connection with the dietary habits of many industrialized nations, could possibly help to explain another factor of obesity. The invention of the light bulb made the once unproductive and dark night as valuable and bright as day. Now, people can work 24 hours a day, making industry and the lives that run it more crowded and hectic. More and more people are trying harder and harder to fit more into their days, and as a result, sleep is often slighted. The ultimate effect of this new lifestyle is more stress and a greater usage of artificial light, which are now proving to reset the Circadian Rhythm as much as exposure to the sun. This means that in highly industrialized countries in which artificial lights can make the night as bright as the day, people tend to be more sleep deprived(6). Scientists have proven that shining lights on rats causes them to awake earlier than if a light had not been shown. The same is true with humans(7). When the body awakens too early, it cannot fully restore itself, making the chemical imbalances remain imbalanced. Thus while people think that they are waking up because the body has had enough sleep, it is really because the body's Rhythm is off. And as a result, these people think that they are getting enough sleep, when in actuality, they are hurting the body more by off setting its own natural clock and the natural processes that occur during sleep.

Sleep is a major part of our lives, this is more than evident by the fact the most scientists would agree that the average person needs between seven to ten hours of sleep a day – that is almost one third of an entire lifetime spent sleeping. Once thought to be only a necessary for the brain's functioning alone, it is becoming more and more apparent that the body needs sleep just as much if not more than the brain. Besides reviving energy, sleep maintains chemical balances that create better moods, stabilize chemical imbalances, and even ensure that the body is working at its best capabilities to ward off disease and even obesity. Living in a country that now forces the night to be just as industrially productive as the day, also affects how much each person sleeps, regardless of when they try to go to bed. The body sets its own natural clock by comparing itself to light, be it the sun or now artificial light from light bulbs. As a result, the body can get confused as to when it is supposed to perform the actions necessary during sleep. Before the invention of electricity, the body and brain could easily set their own Rhythm, maintaining themselves and warding off the now apparent physical effects of too little sleep. Now that individuals have more control over their body's natural processes via artificial means, it is more important than ever to realize that sleep does not just effect the mind but also the body.

References

1)http://www.sciencedaily.com/releases/1999/03/990316063522.htm
2)http://home.attbi.com/~rnagle557/dream_sleepscience.htm
3)http://www.fda.gov/fdac/features/1998/sleepsoc.html
4)http://abcnews.go.com/sections/2020/2020/2020_010330_sleep.html
5)http://home.attbi.com/~rnagle557/dream_sleepscience.htm
6)www.ivillagehealth.com
7)http://www.sciencedaily.com/releases/1999/03/990316063522.htm