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By Nicholas Bakalar Women with sleeping difficulties are at increased risk for Type 2 diabetes, researchers report. Scientists used data from 133,353 women who were generally healthy at the start of the study. During 10 years of follow-up, they found 6,407 cases of Type 2 diabetes. The researchers looked at four sleep problems: self-reported difficulty falling or staying asleep, frequent snoring, sleep duration of less than six hours, and either sleep apnea or rotating shift work. The study is in Diabetologia. Self-reported difficulty sleeping was associated with higher B.M.I., less physical activity, and more hypertension and depression. But even after adjusting for these and other health and behavioral characteristics, sleeping difficulty was still associated with a 22 percent increased risk for Type 2 diabetes. Compared to women with no sleep problems, those with two of the sleep conditions studied had double the risk, and those with all four had almost four times the risk of developing the illness. The senior author, Dr. Frank B. Hu, a professor of nutrition and epidemiology at Harvard, said that sleep problems are associated with excess secretion of two hormones: ghrelin, which increases appetite, and cortisol, which increases stress and insulin resistance. Both are linked to metabolic problems that increase the risk for diabetes. “And,” he added, “it’s not just quantity of sleep, but quality as well” that is associated with these health risks. © 2016 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 21856 - Posted: 02.04.2016

By JAN HOFFMAN One evening in the late fall, Lucien Majors, 84, sat at his kitchen table, his wife Jan by his side, as he described a recent dream. Mr. Majors had end-stage bladder cancer and was in renal failure. As he spoke with a doctor from Hospice Buffalo , he was alert but faltering. In the dream, he said, he was in his car with his great pal, Carmen. His three sons, teenagers, were in the back seat, joking around. “We’re driving down Clinton Street,” said Mr. Majors, his watery, pale blue eyes widening with delight at the thought of the road trip. “We were looking for the Grand Canyon.” And then they saw it. “We talked about how amazing, because there it was — all this time, the Grand Canyon was just at the end of Clinton Street!” Mr. Majors had not spoken with Carmen in more than 20 years. His sons are in their late 50s and early 60s. “Why do you think your boys were in the car?” asked Dr. Christopher W. Kerr, a Hospice Buffalo palliative care physician who researches the therapeutic role of patients’ end-of-life dreams and visions. “My sons are the greatest accomplishment of my life,” Mr. Majors said. He died three weeks later. For thousands of years, the dreams and visions of the dying have captivated cultures, which imbued them with sacred import. Anthropologists, theologians and sociologists have studied these so-called deathbed phenomena. They appear in medieval writings and Renaissance paintings, in Shakespearean works and set pieces from 19th-century American and British novels, particularly by Dickens. One of the most famous moments in film is the mysterious deathbed murmur in “Citizen Kane”: “Rosebud!” Even the law reveres a dying person’s final words, allowing them to be admitted as evidence in an unusual exception to hearsay rules. © 2016 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21852 - Posted: 02.03.2016

By Veronique Greenwood Last year a new sleep drug called Belsomra came on the market, featuring a mechanism unlike any other pill: it mimics narcolepsy. That might sound odd, but the potential users are many. More than 8.5 million Americans take prescription sleep aids, and many others use snooze-inducing over-the-counter medications. All these pills, including Belsomra, do one of two things: they enhance the effects of the neurotransmitter GABA, known for quieting brain activity, or they arrest the actions of neurotransmitters that keep the brain aroused. Yet it's not quite as simple as flipping a switch; the drugs have a range of side effects, including daytime drowsiness, hallucinations and sleep-eating. Here's an overview of the sleeping pills currently available in the U.S.—plus a look at cognitive-behavior therapy for insomnia, which may be more successful than drugs alone. It requires a lot more work than popping a pill, but cognitive-behavior therapy for insomnia (CBT-I) has been shown to successfully alleviate sleep problems. Aimed at developing healthy habits, CBT-I comes with a lot of homework—between weekly or so visits with a specialist, a patient keeps track of hours spent in bed and hours sleeping and uses the bed only for sleep and sex. The patient must stay up until an established bedtime and get up on awakening, generating a sleep deficit that makes it easier to fall asleep at the right time. Avoiding caffeine and alcohol after 4 P.M. and timing exercise so that it doesn't interfere with drowsiness are also part of the system. © 2016 Scientific American

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 21770 - Posted: 01.11.2016

Jon Hamilton There's growing evidence that a lack of sleep can leave the brain vulnerable to Alzheimer's disease. "Changes in sleep habits may actually be setting the stage" for dementia, says Jeffrey Iliff, a brain scientist at Oregon Health & Science University in Portland. The brain appears to clear out toxins linked to Alzheimer's during sleep, Iliff explains. And, at least among research animals that don't get enough solid shut-eye, those toxins can build up and damage the brain. Iliff and other scientists at OHSU are about to launch a study of people that should clarify the link between sleep problems and Alzheimer's disease in humans. It has been clear for decades that there is some sort of link. Sleep disorders are very common among people with Alzheimer's disease. For a long time, researchers thought this was simply because the disease was "taking out the centers of the brain that are responsible for regulating sleep," Iliff says. But two recent discoveries have suggested the relationship may be more complicated. The first finding emerged in 2009, when researchers at Washington University in St. Louis showed that the sticky amyloid plaques associated with Alzheimer's develop more quickly in the brains of sleep-deprived mice. Then, in 2013, Iliff was a member of a team that discovered how a lack of sleep could be speeding the development of those Alzheimer's plaques: A remarkable cleansing process takes place in the brain during deep sleep, at least in animals. What happens, Iliff says, is "the fluid that's normally on the outside of the brain — cerebrospinal fluid, it's a clean, clear fluid — it actually begins to recirculate back into and through the brain along the outsides of blood vessels." This process, via what's known as the glymphatic system, allows the brain to clear out toxins, including the toxins that form Alzheimer's plaques, Iliff says. © 2016 npr

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 21748 - Posted: 01.04.2016

By Roni Caryn Rabin Melatonin has been shown to be effective in randomized clinical trials — the kind considered the gold standard in medicine — but it may work better for some sleep problems than others. “There is pretty strong evidence it’s effective for jet lag,” said D. Craig Hopp, a program director at the National Center for Complementary and Integrative Health, part of the National Institutes of Health. But “the evidence is more equivocal for chronic things like insomnia.” A 2002 Cochrane review that analyzed 10 randomized trials, most of them comparing oral melatonin to placebo, concluded that melatonin is “remarkably effective in preventing or reducing jet lag.” It not only helped people fall asleep faster and sleep more soundly, but also led to less daytime fatigue and improved general well-being. Eight of the 10 trials found that taking melatonin for several days after arriving at a destination reduced jet lag from flights crossing at least five time zones. In many of the trials, people also took melatonin on the day of the flight or for several days before the trip, usually in the late afternoon or early evening. Once at the destination, melatonin should be taken close to bedtime, aiming for the local hours between 10 p.m. and midnight. Doses of 0.5 milligrams and 5 milligrams were both effective, though people fell asleep faster and slept better with the larger dose. For others with insomnia, melatonin has more modest benefits. A 2013 analysis that looked at 19 randomized controlled trials involving 1,683 subjects determined that on average, melatonin reduced the amount of time it took to fall asleep by seven minutes when compared with placebo and increased total sleep time by eight minutes. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 8: Hormones and Sex
Link ID: 21734 - Posted: 12.30.2015

Need to remember something important? Take a break. A proper one – no TV or flicking through your phone messages. It seems that resting in a quiet room for 10 minutes without stimulation can boost our ability to remember new information. The effect is particularly strong in people with amnesia, suggesting that they may not have lost the ability to form new memories after all. “A lot of people think the brain is a muscle that needs to be continually stimulated, but perhaps that’s not the best way,” says Michaela Dewar at Heriot-Watt University in Edinburgh, UK. New memories are fragile. They need to be consolidated before being committed to long-term storage, a process thought to happen while we sleep. But at least some consolidation may occur while we’re awake, says Dewar – all you need is a timeout. In 2012, Dewar’s team showed that having a rest helps a person to remember what they were told a few minutes earlier. And the effect seems to last. People who had a 10-minute rest after hearing a story remembered 10 per cent more of it a week later than those who played a spot-the-difference game immediately afterwards. “We dim the lights and ask them to sit in an empty, quiet room, with no mobile phones,” says Dewar. When asked what they had been thinking about afterwards, most volunteers said they had let their minds wander. Now Dewar, along with Michael Craig at the University of Edinburgh and their colleagues, have found that spatial memories can also be consolidated when we rest. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 21721 - Posted: 12.24.2015

Rae Ellen Bichell Ever notice the catnaps that older relatives take in the middle of the day? Or how grandparents tend to be early risers? You're not alone. Colleen McClung did, too. A neuroscientist at the University of Pittsburgh Medical Center, McClung wanted to know what was going on in the brain that changes people's daily rhythms as they age. We all have a set of so-called clock genes that keep us on a 24-hour cycle. In the morning they wind us up, and at night they help us wind down. A study out Monday in Proceedings of the National Academy of Sciences found that those genes might beat to a different rhythm in older folks. "When you think about the early bird dinner specials, it sort of fits in with their natural shift in circadian rhythms," says McClung. "There is a core set of genes that has been described in every animal — every plant all the way down from fungus to humans — and they're pretty much the same set of genes." The genes are the master controllers of a bunch of other genes that control processes ranging from metabolism to sleep. When you woke up this morning, the timekeeping genes told a gland in your brain to give a jolt of the stress hormone cortisol to wake up. Tonight, they'll tell a gland to spit out melatonin, a hormone that makes you sleepy. "You can think of them as sort of the conductor of an orchestra," says McClung. They make sure all the other genes keep time. © 2015 npr

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 13: Memory, Learning, and Development
Link ID: 21717 - Posted: 12.22.2015

Carl Zimmer Over the past few million years, the ancestors of modern humans became dramatically different from other primates. Our forebears began walking upright, and they lost much of their body hair; they gained precision-grip fingers and developed gigantic brains. But early humans also may have evolved a less obvious but equally important advantage: a peculiar sleep pattern. “It’s really weird, compared to other primates,” said Dr. David R. Samson, a senior research scientist at Duke University. In the journal Evolutionary Anthropology, Dr. Samson and Dr. Charles L. Nunn, an evolutionary biologist at Duke, reported that human sleep is exceptionally short and deep, a pattern that may have helped give rise to our powerful minds. Until recently, scientists knew very little about how primates sleep. To document orangutan slumber, for example, Dr. Samson once rigged up infrared cameras at the Indianapolis Zoo and stayed up each night to watch the apes nod off. By observing their movements, he tracked when the orangutans fell in and out of REM sleep, in which humans experience dreams. “I became nocturnal for about seven months,” Dr. Samson said. “It takes someone who wants to get their Ph.D. to be motivated enough to do that.” In the new study. Dr. Samson and Dr. Nunn combined that information with studies of 19 other primate species. The researchers found wide variations in how long the animals slept. Mouse lemurs doze for seventeen hours a day, for example, while humans sleep just seven hours or so a day — “the least of any primate on the planet,” said Dr. Samson. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21712 - Posted: 12.19.2015

By Karen Weintraub Is sleep induced by a benzodiazepine counted as restorative sleep? Researchers hate to admit it, but they don’t know enough about sleep to answer this question. Their best guess, several experts said, is that sleep is sleep. Dr. John Weyl Winkelman, a sleep disorders expert at Massachusetts General Hospital and Harvard Medical School, said if a patient asked him whether medicated sleep was restorative, “I’d say: ‘You tell me.’” There is quite a bit of evidence about the negative health consequences of insomnia, but researchers don’t know precisely what it is in the brain and body that is "restored" by sleep to aid optimal function. And it is unlikely that any specific stage of sleep is uniquely restorative, said Dr. Daniel J. Buysse, a sleep medicine expert and professor of psychiatry at the University of Pittsburgh. More sleep, less interrupted sleep, and sleep at the right time of night are all likely to be important, he said. There are two types of sleep: REM, when people dream, and non-REM, which has light, medium and deep portions. Sleeping pills mainly increase the amount of medium-depth non-REM sleep, Dr. Buysse said. Medications can help people fall asleep faster and reduce nighttime wakefulness, he said, and those changes are usually considered to contribute to restorative sleep. But different people respond differently. “Do you feel more rested, more alert, more able to concentrate, less irritable on medication versus off?" Dr. Buysse said. "If all those things are true then I would say it’s more restorative. If a hypnotic drug leaves you feeling hung over or more anxious, if it causes you to order five hickory smoked turkeys on the Internet without remembering, then it’s probably not good.” © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 21691 - Posted: 12.12.2015

By Nicholas Bakalar Several studies have shown that there is an association between shift work and an increased risk for heart disease and diabetes. Now a new study, in the Journal of Clinical Endocrinology & Metabolism, has found a similar association in people whose sleeping schedules change on the weekend. For seven days, 447 men and women ages 30 to 54 wore devices that measured movement and tracked when they fell asleep and woke. Almost 85 percent of the group went to sleep and woke later on their days off than during the workweek. The researchers found that the greater the mismatch in sleep timing between weekdays and weekends, the higher the metabolic risk. Sleeping late on days off was linked to lower HDL (good) cholesterol, higher triglycerides, higher insulin resistance and higher body mass index. The associations persisted after controlling for physical activity, caloric intake, alcohol use and other factors. “It’s not clear yet that this is a long-term effect,” said the lead author, Patricia M. Wong, a graduate student at the University of Pittsburgh. “But we think of this as people having to sleep and work out of sync with their internal clock, and that having to be out of sync may be having these health effects.” © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21651 - Posted: 11.21.2015

By Rachel E. Gross For decades, Michael Jackson had struggled to fall asleep at night. But in 2009 the pop singer was preparing for his worldwide comeback tour, and he couldn’t afford to be at anything less than 100 percent. Desperate for sleep, he convinced an unscrupulous physician to give it to him synthetically in the form of an anesthetic so strong that it sent him almost immediately into a “druglike coma.” At first, Jackson would wake up feeling refreshed. But the nightly injections conferred only the shadow of true sleep, with none of the deep, dream-filled REM cycles that his body needed. Soon he was fading fast, his mind and mood slipping away. Within two months Jackson was dead of an overdose. If that hadn’t killed him, doctors later testified during his wrongful death trial, he would have died of sleep deprivation. Jackson’s is a particularly dramatic case. But his struggle for oblivion rings true to anyone who has dealt with insomnia. “I’m for anything that gets you through the night,” Frank Sinatra once said, “be it prayer, tranquilizers, or a bottle of Jack Daniel’s.” If you have insomnia, you’ll understand this sentiment, and you’re not alone: Regular sleep eludes up to 15 percent of the population, making insomnia the most commonly diagnosed sleep problem in America. Fortunately, the nighttime affliction is becoming steadily less mysterious—at least from the perspective of neuroscience. While insomniacs toss and turn, researchers are finally starting to understand this elusive disease. As it turns out, chronic insomnia may be more hard-wired into our brains than we had thought, and indicative of larger differences that separate the brains of the sleepless from those who so effortlessly enter the land of dreams. © 2015 The Slate Group LLC

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21614 - Posted: 11.07.2015

By Jan Hoffman As the first semester of the school year reaches the halfway mark, countless college freshmen are becoming aware that their clothes are feeling rather snug. While the so-called freshman 15 may be hyperbole, studies confirm that many students do put on five to 10 pounds during that first year away from home. Now new research suggests that an underlying cause for the weight gain may be the students’ widely vacillating patterns of sleep. A study in the journal Behavioral Sleep Medicine looked at the sleep habits of first-semester freshmen. Researchers followed 132 first-year students at Brown University who kept daily sleep diaries. After nine weeks, more than half of them had gained nearly six pounds. There are many poor sleep habits that might have exacerbated their weight gains, a growing body of research indicates. Was it abbreviated sleep? Optimally, experts say, teenagers need about nine hours and 15 minutes a night. These freshmen averaged about seven hours and 15 minutes. In a study earlier this year, in the journal PLOS One, researchers found that when teenagers are sleep-deprived, they more readily reach for candy and desserts. Or were the Brown students’ late bedtimes the scale-tipping factor? On average, they went to bed around 1:30 a.m. A study this month in the journal Sleep that followed teenagers into adulthood found that each hour later bedtime was pushed during the school or workweek was associated with about a two-point increase in body mass index. While both the amount of sleep and the lateness of bedtime may have played a role, the researchers in the Brown study identified a new sleep factor for predicting weight gain: variability, or the extent to which a student’s bedtime and waking time changed daily. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 21573 - Posted: 10.27.2015

By Nicholas Bakalar A new study has found that sleep apnea is associated with an increased risk for gout, a painful disease of the big toe and other joints caused by elevated levels of uric acid in the blood. Observational studies have shown that people with sleep apnea have a higher prevalence of excess uric acid, but until now it has been unclear whether sleep apnea is associated with gout, and how strongly. Using records in a British health database, researchers studied 9,865 people, average age 54, with sleep apnea and matched them to 43,598 controls without the disorder. Because sleep apnea is associated with being overweight, the participants were matched for B.M.I., among many other characteristics. The study is in Arthritis & Rheumatology. After one year, compared with controls, people with sleep apnea were about 50 percent more likely to have had an attack of gout, and the increased risk was found without regard to sex, age or obesity. The conclusion suggests that treating sleep apnea would reduce gout attacks, but the lead author, Yuqing Zhang, a professor of medicine at Boston University, is cautious. “Our findings call for future studies to evaluate the effect of treating sleep apnea on serum uric acid levels and the risk of gout,” he said. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21563 - Posted: 10.26.2015

By Jonathan Webb Science reporter, BBC News Crocodiles can sleep with one eye open, according to a study from Australia. In doing so they join a list of animals with this ability, which includes some birds, dolphins and other reptiles. Writing in the Journal of Experimental Biology, the researchers say the crocs are probably sleeping with one brain hemisphere at a time, leaving one half of the brain active and on the lookout. Consistent with this idea, the crocs in the study were more likely to leave one eye open in the presence of a human. They also kept that single eye trained directly on the interloper, said senior author John Lesku. "They definitely monitored the human when they were in the room. But even after the human left the room, the animal still kept its open eye… directed towards the location where the human had been - suggesting that they were keeping an eye out for potential threats." The experiments were done in an aquarium lined with infrared cameras, to monitor juvenile crocodiles day and night. "These animals are not particularly amenable to handling; they are a little snippy. So we had to limit all of our work to juvenile crocodiles, about 40-50cm long," said Dr Lesku, from La Trobe University in Melbourne. As well as placing a human in the room for certain periods, the team tested the effect of having other young crocs around. Sure enough, these also tended to attract the gaze of any reptiles dozing with only one eye. This matches what is known of "unihemispheric sleep" in aquatic mammals, such as walruses and dolphins, which seem to use one eye to make sure they stick together in a group. © 2015 BBC.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 15: Brain Asymmetry, Spatial Cognition, and Language
Link ID: 21548 - Posted: 10.22.2015

By Nicholas Bakalar Sleep apnea may be even more dangerous for women than for men, a new study suggests. Epidemiological studies have linked sleep apnea to heart disease in men, but the differences in risk between men and women have been largely unexplored. For the current study, researchers measured sleep quality electronically in 737 men and 879 women, average age 63, who were free of cardiovascular disease at the start of the study. They also tested all of them for troponin T, a protein that can be released into the bloodstream if the heart is damaged, and whose presence in otherwise healthy people indicates an increased risk for heart disease. They tracked the participants for 14 years, recording incidents of coronary artery disease, heart failure and death from cardiovascular disease or other causes. The study was published in Circulation. Obstructive sleep apnea was independently associated with increased troponin T, heart failure and death in women, but not in men. And in women, but not men, sleep apnea was associated with an enlarged heart, another risk factor for cardiovascular disease. “Most people who have sleep apnea have a lot of other risks for heart disease,” said the lead author, Dr. Amil M. Shah, an assistant professor of medicine at Harvard. “But in women, the relationship between sleep apnea and heart disease persisted even after accounting for the other risks.” “Even among women with sleep apnea who don’t get heart failure,” he continued, “it’s associated with changes in the heart that lead to worse outcomes.” © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 8: Hormones and Sex
Link ID: 21547 - Posted: 10.22.2015

By Anahad O'Connor For years, public health authorities have warned that smartphones, television screens and the hectic pace of modern life are disrupting natural sleep patterns, fueling an epidemic of sleep deprivation. By some estimates, Americans sleep two to three hours fewer today than they did before the industrial revolution. But now a new study is challenging that notion. It found that Americans on average sleep as much as people in three different hunter-gatherer societies where there is no electricity and the lifestyles have remained largely the same for thousands of years. If anything, the hunter-gatherer communities included in the new study — the Hadza and San tribes in Africa, and the Tsimané people in South America — tend to sleep even less than many Americans. The findings are striking because health authorities have long suggested that poor sleep is rampant in America, and that getting a minimum of seven hours on a consistent basis is a necessity for good health. Many studies suggest that lack of sleep, independent of other factors like physical activity, is associated with obesity and chronic disease. Yet the hunter-gatherers included in the new study, which was published in Current Biology, were relatively fit and healthy despite regularly sleeping amounts that are near the low end of those in industrialized societies. Previous research shows that their daily energy expenditure is about the same as most Americans, suggesting physical activity is not the reason for their relative good health. The prevailing notion in sleep medicine is that humans evolved to go to bed when the sun goes down, and that by and large we stay up much later than we should because we are flooded with artificial light, said Jerome Siegel, the lead author of the new study and a professor of psychiatry at the Semel Institute of Neuroscience and Human Behavior at U.C.L.A. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21523 - Posted: 10.17.2015

Chris Samoray People in the postindustrial world don’t always get a sound night sleep. But they appear to spend a similar amount of time sleeping as do people in hunter-gatherer communities in Africa and South America, a new study finds. “It’s absolutely clear that they don’t sleep more than we do,” says Jerome Siegel, a UCLA sleep scientist. In fact, on average, hunter-gatherers may sleep a little less. Recommended nightly sleep for adults is typically seven to nine hours; a 2013 Gallup poll showed that most Americans get around 6.8 hours. On most nights, members of three hunter-gatherer groups — the Hadza of Tanzania, the Ju/’hoansi San of Namibia and the Tsimane of Bolivia — sleep 5.7 to 7.1 hours, Siegel and colleagues report online October 15 in Current Biology. That’s on the lower end of the sleep spectrum in postindustrial societies, the researchers say. Evidence from the new study also suggests that these groups experience less insomnia than sleepers in postindustrial societies. (The three hunter-gatherer languages even lack a word for insomnia.) Hunter-gatherer sleep patterns are closely tied to temperature, a new study shows. Among the Hadza of Tanzania, for instance, people fell asleep about three hours after sunset, on average, as ambient temperatures decreased. People then woke up about an hour before sunrise, when temperatures reached their lowest point. © Society for Science & the Public 2000 - 2015.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21520 - Posted: 10.16.2015

Joe Palca Mothers have been warned for years that sleeping with their newborn infant is a bad idea because it increases the risk the baby might die unexpectedly during the night. But now Israeli researchers are reporting that even sleeping in the same room can have negative consequences: not for the child, but for the mother. Researchers at Ben-Gurion University of the Negev wanted to see whether sleeping in the same room as their newborn affected mothers' or babies' sleep. The short answer: It did, and the effect wasn't good for moms. The researchers recruited 153 married couples expecting their first child to participate in the study. The new parents weren't told where or how to sleep. They were simply asked to record whether they slept in the same room as their newborn, the same bed and same room, or if the child slept in another room. To measure sleep patterns, both mom and baby wore wristbands designed to measure movement during the night, a measurement that gives a pretty accurate indication of sleep patterns for both mother and child. The researchers measured sleep patterns before the babies were born, at 3 months and at 6 months. Mothers who slept in the same room as their infants, whether in the same bed or just the same room, had poorer sleep than mothers whose babies slept elsewhere in the house: They woke up more frequently (approximately three times per night versus two), were awake approximately 20 minutes longer per night, and had shorter periods of uninterrupted sleep (approximately 136 minutes versus 166 minutes). These results held true even taking into account that many of the women in the study were breast-feeding their babies. © 2015 NPR

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21468 - Posted: 10.03.2015

Dark puffy eyes, a feeling of deep exhaustion, and a foul mood to match – we’ve all experienced the side effects of a lack of sleep. It’s no wonder that sleep-deprivation has been used as a method of torture. Our brains seem to lose the ability to distinguish between the innocuous and emotional in such circumstances, turning us into overreacting, exhausted wrecks. We all know that a good night’s sleep is vital for a day of clear thinking, but exactly why sleep is so important remains a mystery. Talma Hendler of Tel Aviv University in Israel is particularly interested in how lack of sleep leaves us with a short emotional fuse. “We know that sleep affects our emotional behaviour, but we don’t know how,” she says. To investigate further, Hendler and her colleagues kept 18 adults awake all night. “It took a great effort,” she says. “During the night, we repeatedly measured their sleepiness, and unsurprisingly they got more and more tired.” The volunteers were put through two rounds of tests while their brains were scanned, both the day after a good night’s sleep and after being awake for 24 hours. In one test, volunteers were asked to give the direction in which yellow dots moved on a screen. In each case, the dots were laid over a potentially distracting picture that was either positively emotional (of a kitten or a couple in love, for example), negatively emotional (such as a mutilated body or a snake) or neutral (such as a cow or spoon). © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 11: Emotions, Aggression, and Stress
Link ID: 21445 - Posted: 09.26.2015

By C. CLAIBORNE RAY A. Wild canines that rely on strenuous hunting to survive may sleep or rest as much as, or even more than, indolent human-created breeds that rely on a can or a bag of kibble. Domestic dogs, with their great range of body types and personalities, show a tremendous variety of sleep patterns, often including relatively brief periods of deep sleep spread out over several hours. A half-century-long study of wolves and their interaction with their prey on Isle Royale, a wilderness island in Lake Superior, found that in winter the wolves would feed for hours on a fresh kill, then sprawl out or curl up in the snow and rest or sleep about 30 percent of the time. “Wolves have plenty of reason to rest,” the study’s researchers wrote. “When wolves are active, they are really active. On a daily basis, wolves burn about 70 percent more calories compared to typical animals of similar size.” The researchers note that while hunting, wolves may burn calories at 10 to 20 times the rate they do while resting. “When food is plentiful, wolves spend a substantial amount of time simply resting, because they can,” the study said. “When food is scarce, wolves spend much time resting because they need to.” Wolves may eat only once every five to 10 days, the researchers said, losing as much as 8 to 10 percent of body weight, but regaining all the lost weight in just two days of eating and resting. © 2015 The New York Times Company

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 21419 - Posted: 09.20.2015