Here's the second part of my summary of the 60 Minutes segment on the importance of sleep. Note especially the information about the effect of sleep deprivation on health.
Dinges says people who are chronically sleep deprived, like people who've had too much to drink, often have no sense of their limitations. They believe they've trained themselves. "I think it's a convenient belief. For the millions of people who don't get enough sleep because their commute to work is too long, or they spend too many hours at work, or they just want this lifestyle of go, go, go, it's convenient to say, 'I've learned to live without sleep.' But you bring ‘em into the laboratory - and we have an open challenge to any CEO or anyone in the world, come into the laboratory - we don't see this adaptation," he says.
One thing sleep researchers do see is that their sleep-deprived volunteers often have mood swings: they get short-tempered, then become almost giddy, sometimes within seconds.
Matthew Walker describes a study in which his team deprived a group of college students of sleep for 35 hours straight. Their brain response became hyperactive. But it got even worse.
And what's more, in the sleep-deprived subjects, Walker discovered a disconnect between that over-reacting amygdala (a region of the brain) and the brain's frontal lobe, the region that controls rational thought and decision-making, meaning that the subjects' emotional responses were not being kept in check by the more logical seat of reasoning. It's a problem also found in people with psychiatric disorders.
"So you're saying that you take someone with a severe mental disorder and a person without that disorder, but deprive them of sleep, and the brain scan will look similar?" Stahl asks.
"Their pattern of brain activity was not dissimilar. So I think what it forces us to do really now is to appreciate more significantly the role that sleep may be playing in mental health and in psychiatric diseases. And I think that could be one of the futures of the field of sleep research," Walker replies.
According to Walker (and I’ve read this same thing for years and years) most of us need seven and a half to eight hours of sleep every night.
By almost all measures, we are sleeping less than ever before. In 1960, a survey by the American Cancer Society asked one million Americans how much sleep they were getting a night. The median answer was eight hours. Today that number has fallen to 6.7 hours-a decrease of more than 15 percent in less than a lifetime. And from what the scientists 60 Minutes met are finding, we may be putting ourselves in a perilous situation.
Eve Van Cauter, an endocrinologist at the University of Chicago School of Medicine, studies the effect of sleep on the body. In a recent study, she made a shocking discovery:
"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’s 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’re full. (Emphasis mine)
I was amazed to read this. Our obesity epidemic may not be merely the result of poor diet and lack of physical activity. It may also be caused by lack of sleep! Whoda thunk it? Other studies have confirmed this:
Several large-scale studies from all over the world have reported a link between short sleep times and obesity, as well as heart disease, high blood pressure, and stroke.
According to Van Cauter, we are not biologically cut out for the deprivation of sleep that we visit upon ourselves.
"You know, our attitude about sleep flies in the face of what you're saying. Because I think that 'You don't need as much sleep' is looked upon as something very positive," Stahl remarks.
"It's seen as a badge of honor," Van Cauter agrees. "But you know I find it amazing to see how many people are asleep within five minutes of boarding an airplane at 11 o'clock in the morning. You know, sit down and boom. It shouldn't happen. A normal adult shouldn't be falling asleep at 11 o'clock in the morning, minutes after sitting in a small, uncomfortable airplane seat. It just shows that, you know, people are exhausted."
Can you relate to this? I certainly can. At just about any time of any day, if I put my head down and turn out the lights, I will be asleep in almost no time.
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.
"We usually think of diabetes as something that's a disease of old age. But really it may be a disease of sleep deprivation," Stahl remarks.
"I would say that sleep deprivation may be a new risk factor for diabetes," Van Cauter says. "Not just aging, not just being overweight or obese, not just having a family history of diabetes, which are the three major risk factors. But this is an added one. And we have really an epidemic of diabetes now. And Type 2 diabetes is now occurring in children, in adolescents. And, you know, adolescents and children too are also being sleep deprived. Maybe high schoolers are amongst the most sleep deprived individuals in our society, because they have an enormous sleep need - nine to ten hours. Yet they sleep less than seven hours per night."
She says this research proves we all need to rethink what we consider essential for good health - that the diet and exercise formula also has to include sleep.
Finally, the article discusses the concept of napping. I loved its conclusion!
Scientists tell 60 Minutes that what's most important is getting your seven and a half to eight hours total, so naps can help. (And Fr. James said…AMEN!) And brand new research is showing that long naps, including REM sleep, can even improve emotional outlook, making people less sensitive to negative experiences and more receptive to positive ones.
I hope you enjoyed this article summary. To watch the segment, or read the transcript, please click here. Now if you’ll excuse me, I’m off to take a nap!