On March 16th, CBS NEWS published: The Science of Sleep, the latest findings in sleep research explored by Lesley Stahl. Human beings spend on average one third of their lives asleep. We know we need to sleep but most of us have never really given a whole lot of thought to why. As it turns out no one really knows for sure why, but scientists are discovering that sleep is far more critical to human health than previously believed and have linked sleep deprivation to serious problems such as diabetes and heart disease.

Luck of sleep was the subject of a NIH-funded study at the University of Pennsylvania’s School of Medicine led by the scientist, David Dinges. “The first finding, and it stunned us, was there is a cumulative impairment that develops in your ability to think fast, to react quickly, to remember things. And it starts right away,” Dinges says. “A single night at four hours or five hours or even six, can in most people, begin to show affects in your attention and your memory and the speed with which you think. A second night it gets worse. A third night worse. Each day adds an additional burden or deficit to your cognitive ability.” More observations

Another study at the University of Chicago’s School of Medicine conducted by Eve Van Cauter, an endocrinologist, studies the effect of sleep on the bodies of healthy, young volunteers. “We did a study where we restricted sleep to four hours per night for six nights,” Van Cauter explains. “And we noticed that they were already in a pre-diabetic state. And so, that was a big finding.” The study’s subjects were on the road to diabetes in just six days, and that is not all - they were also hungry. Van Cauter has made a radical discovery: that lack of sleep may be contributing to the epidemic of obesity in this country through the work of a hormone called leptin that tells your brain when you are full. After four nights without deep sleep, the study subjects were hungrier, less alert, and most importantly, their bodies were no longer able to metabolize sugar effectively, putting them temporarily at increased risk for Type 2 diabetes.

Dr. Eve Van Cauter together with her colleague Dr. Esra Tasali also experiment with quality of sleep. During a normal night, we cycle through different stages of sleep, progressing from light into deep sleep, then into REM (Rapid eye movement), or dream sleep, and back again. As we age, though, the amount of time we spend in deep sleep decreases. Van Cauter and Tasali are investigating a novel theory that some of the health problems we typically associate with old age may in fact be caused by the loss of deep sleep. “We lose deep sleep at a very early age. So a young, healthy person may have 100 minutes of deep sleep, and at 50 years old it may be as little as 20 minutes. So it really… goes down very quickly,” Van Cauter explains. Other conclusions.

As far as goes about the possibility to figure out a way to get along with less sleep, Eve Van Cauter says: “My impression is that sleep affects so many aspects of mental and physical function, that there's not going to be one magic bullet drug that will be able to compensate. Much better idea is simply to sleep an hour more.” The results of these studies show that lack of sleep impacts our appetite, our metabolism, our memory, and also how we age. Years long believe that good diet and exercise are essential for good health may graduate to new level incorporating sleep. Short recap by Lesley Stahl.

Tags: Sleep