Collected Articles on Sleep

Low bedroom temperatures and a thin blanket improve metabolism, increase energy consumption and help with weight loss.

The reason for this is a subtle transformation of the “brown fat reserves”. The brown fat is considered the “good fat”. Until recently, this fat was thought to be found only in infants, but not in adults.

A few years ago, small deposits of brown fatty tissue were discovered in the neck and upper back, even in adults. This is important because the brown fatty tissue can stimulate the metabolism.

Experiments on mice had previously shown that sugar is taken from the blood to burn calories in order to maintain the body’s core temperature.

In order to better understand the activity of brown fat, the National Institutes of Health has induced five young men to spend four months in climatic chambers at different temperatures. Care was taken to ensure that everyone consumed the same amount of calories.

In the first month, the temperature was set to a moderate 24°. As expected, there were no changes in metabolism.

In the second month the temperature was lowered to 19°. And noticeably clear changes were observed: the volume of brown adipose tissue doubled. Insulin sensitivity, which reacts to changes in blood sugar, improved, reports Francesco S. Celi, the lead investigator (now professor at Virginia Commonwealth University). “It was all healthy young men who participated. And only sleeping in cool rooms improved their metabolic quality”. They had a lower risk of diabetes and other metabolic problems.

During the day, too, increased energy combustion was registered in the subjects, but this was not sufficient to reduce the weight within the four weeks.

In the third month at chilly 27° all improvements disappeared and finally the men had even less brown fat than at the first examination.

The message of his study, Celi says, is that one can easily improve the health of the metabolism by simply turning down the thermostat by a few degrees.

Source: New York Times Magazine from 20. 7.2014

Prolong deep sleep by hypnosis.

Sleep researchers at the University of Zurich and Fribourg, led by Maren Cordi and Björn Rasch, have shown that deep sleep can be significantly improved by simple hypnosis techniques. And this is important, because deep sleep is not only important for physical recovery, but also for the memory and strength of the immune system.
In the study, deep sleep was controlled by EEG, i.e. by electrical brain impulses that appear as smooth, slow wave movements in deep sleep.

For the test, 70 young and healthy women were invited to a 90-minute nap in the sleep laboratory. Previously, the women were divided by a test into medium-well hypnotizable and less well hypnotizable. It is estimated that about half of the female population is reasonably well hypnotizable, while men are statistically slightly lower. Hypnosis was initiated by listening to a text with suggestive expressions such as “sleep deeper”.

After the study, the researchers came to the conclusion that hypnosis had increased the proportion of deep sleep in women who could be hypnotized in the middle by 80 % and that the waking time had been reduced by one third. The less hypnotizable women had no advantage from hypnosis.

The researchers concluded that people with sleep problems and especially the elderly could benefit from hypnosis if they respond to hypnosis, because hypnosis is free of side effects.

Source: Switzerland Magazine of 2 June 2014

New function of sleep discovered: Taking out the Trash.

During sleep, the brain sponges out metabolic waste products.

Despite the discovery of this physiologically significant process, the meaning of sleep remains mysterious. But if you consider that not only humans but also all animals are dependent on sleep.

Scientists at Rochester University, New York, have found that the brain is much more flushed by brain fluid during sleep than when awake. It was already known that the astrocytes (glial cells) regulate the flow of brain fluid by swelling and shrinking.
The researchers at Rochester University have now been able to use injected dyes to observe and measure that the gaps between the cells during sleep increase by 60% compared with the waking state and that the outflow doubles in some places.

Maiken Nedergaard of Rochester University, New York, notes that sleep radically changes the cellular structure of the brain so that it seems to change into a completely different state.

Sleep remains a mystery.

Science 18 October 2013:
Vol. 342 no. 6156 pp. 373-377
DOI: 10,1126/science.1241224

Sleep apnea, obesity and support stockings

Overweight people are most affected by sleep apnea (nocturnal breathing stops). This is probably due to the fact that fat accumulates in the airways and narrows the airways. When the muscles of the upper respiratory canals relax during sleep, the pharynx collapses and breathing stops, Prof. Karl Hörmann from the HNO University Hospital in Mannheim reports.
According to Prof. Hörmann, breathing stops can be reduced by half by reducing the body weight by 10 %.

Source: World online / 31.05.2012

Support stockings against breathing stops

We are also interested in the news that support stockings can help with nocturnal breathing stops. However, this message refers to people suffering from venous insufficiency.

Based on the hypothesis that fluid accumulates in the legs of people with weak veins during the day, which then flows into the neck area while lying down at night, thereby restricting the trachea, researchers from the University of Brescia have carried out investigations.

They let patients with vein weakness wear compression stockings for a whole week and then monitor their breath at night. It turned out that after just one week, breathing interruptions were reduced by 36% per hour.

Source: World online / 08/12/2011

Older people need less sleep but are still rested

A university study confirms the old popular wisdom that old people need less sleep than younger people. The study of the University of Surrey in Guildford near London was conducted with 110 persons in 3 different age groups. All subjects had not previously suffered from sleep disorders.

The evaluation of the study showed that the subjects aged between 40 and 55 slept on average 23 minutes less during the nightly rest period of 8 hours than the persons in the age group between 20 and 30 years. Another age group between 66 and 83 years slept 20 minutes less on average, so that the difference between the youngest and the oldest group was about 45 minutes.

The young subjects needed 8 – 9 minutes to fall asleep, the older ones about 14 minutes. The group of researchers led by Derk-Jan Dijk was surprised that despite less sleep, the elderly did not show themselves more tired or exhausted than the younger ones.

An explanation for the different sleep needs could not be given.

Source: World Online from 02.02.2010
Original: SLEEP 2010;33(2):211-223 (Official Publication of the Associated Professional Sleep Societies, LLC

Why the French don't know of a feather bed

The beds traditionally handed down from the northern part of Europe are referred to in museum literature as box beds, frames or doorframe beds. The most obvious feature are the high side walls, which were probably necessary for climatic reasons to accommodate a larger quantity of insulating materials such as hay or straw. The frame and box beds have evolved from the Nordic wardrobe beds.

The flatter post beds, on the other hand, are found in the tradition, which consist of a frame with boards or straps supported by four corner posts. The tradition of postbeds originates from the Mediterranean region. The fact that postbeds can now be found in the traditions in northwest Germany and Rhineland can be explained by the fact that these regions were centres of Roman colonies.

This borderline of the meeting of Nordic beds with Mediterranean bed culture and the influence of cultural traditions can also be seen in the fact that the French do not know of duvets and still do not use duvets even today, although the climate in large parts of France can be compared with that in Germany.

Lucid dreaming

Clear Dreaming is a newer term for an ancient Indian and Tibetan technique of becoming aware of dreaming and intervening in dreams. The dreamer “can not only control his own actions, but also influence the dream environment. The perception of the dream plot is usually not blurred and incoherent as usual, but almost more realistic than reality itself”. (Quote Wikipedia)

This astonishing art of “clear dreaming” was only noticed in the western world in the 1980s (probably not least due to the influence of Carlos Castaneda’s books) and has been studied by various scientific institutions ever since. It has turned out that “clear dreaming” can be learned (up to a certain level) and can also be used to improve performance.

The Sport Institute of the University of Heidelberg is looking for test participants for online experiments and provides information on “clear dream acquisition techniques”. See under: 

Germans prefer to sleep on the side

Sleeping position:
According to a survey by TNS-Emnid on “World Sleep Day 2009”, 80% of respondents prefer to sleep on their sides, 31% on their backs and 24% on their stomach.

Sleeping clothes:
47% of respondents sleep in pyjamas, 16% in T-shirts, 15% in nightgowns and 5% naked. 12% sleep with panties.

Sleeping environment:
5% of respondents prefer a cool room for the night, 24% prefer a warm room. Accordingly, 57% sleep with the window open and 41% with the window closed.

This survey was carried out on behalf of the “Infoservice Gesunder Schlaf” (Lundbeck GmbH) on 1002 men and women over 14 years of age. Source: from 19.03.2009

Lucid dreaming to improve sporting performance

Scientists at the University of Heidelberg have found out in experiments that clear dreaming can also improve sporting performance. In one experiment, for example, they practiced throwing coins into a cup two metres away. The hit rate among the test persons who had practiced in the clear dream was 40 percent higher than among those who had not participated in the nightly exercise.

Clear dreaming or lucid dreaming describes the paradoxical state of being “awake” during sleep and being able to largely control the dreaming process.

The scientific confirmation of this phenomenon was also proven by the Heidelberg scientists in various experiments.

The problem is that the body is largely paralyzed during the dream phase (the so-called REM phase, which is characterized by rapid eye movement).

Earlier investigations by American dream researchers have therefore been based on previously agreed signs with the eyes to prove the existence of clear dreaming.

The Heidelberg researchers have now shown that movements and physical activities in dreams can be measured as fine muscle twitches. During hard dream work (squats) an increased respiratory rate and an increase in heartbeat could also be demonstrated.

According to the scientists, clear dreaming can be learned with little practice. The technique sounds simple: one should ask oneself several times during the day whether one dreams until this question is firmly memorized and finally also appears in the dream in order to be able to be answered in the affirmative. In addition, one should maintain the clarity of the state of consciousness when falling asleep and take it into the dream (!??)

According to Brigitte Holzinger of the Institute for Research on Consciousness and Dreams in Vienna, clear dreams should also be helpful for nightmares, as she found out in a study. The test persons first participated in a Gestalt therapy aimed at making them aware of their own healing powers. Subsequently, the patients were divided into two groups. A group of them was then trained in clear dreaming. A comparison of both groups showed that the clear dreamers could sleep better than the control group.

Source FAZ Nature and Science from 11.04.2007

For information on the clear dream, see 

Stiftung Warentest considers mattress lying areas of different hardness to be ineffective.

In the test of expensive pocket springs (September 2009 issue), the Stiftung Warentest test showed that the so-called lying areas of the mattresses can hardly have any effect, in contrast to the advertising statements. Because these zones are hardly noticeable.
For this purpose, Stiftung Warentest systematically scanned the mattress using a test stamp in a new type of test procedure. The test stamp was pressed into the mattress at regular intervals 5 cm and 7 cm deep. The force required for this was registered and in this way the supporting force or elasticity of the mattress was determined.

To the examiners’ astonishment, only minimal differences were found in the majority of the mattresses examined, so that there can be no question of an effective zone effect.
This result did not seem to the testers to be a disadvantage for the lying comfort, because especially on the mattresses without recognizable zone effect they lay best.

Irrespective of this, Stiftung Warentest does not see any advantage in more effective lying areas, as at best people with average measurements can use them. And this is only possible if they lie down in the right places and maintain this position all night long.

Extended nap can shorten life

A seven-year study by California Pacific Medical Center of 8101 white Americans over 69 years of age found that a regular prolonged nap can shorten life:

44% of women who took regular naps died sooner than women who only took an occasional nap.

Women who slept more than 8-9 hours a day were also much more likely to die earlier.

In all the deceased of the women involved in the study, the cause of death heart and circulatory failure was 59% higher among the “frequent sleepers” than among the women who slept less.

However, the study’s statement that the excessive need for sleep is caused by nocturnal sleep disorders is relativized. Because then the problem lies in the causes of the nocturnal sleep disturbances, which it is necessary to find and heal, as the co-author of the study Katie L. Stone communicated.

Quelle Focus online from 05.03.09 / Origin Journal of the American Geriatrics Society

The brain protects sleeping people from noise

According to an investigation by the Max Planck Institute for Psychiatry in Munich, the brain hides the perception of familiar sounds while sleeping. The normal reaction of the cerebral cortex to sounds is blocked and other areas of the brain responsible for “alarm reactions” are reduced. Apparently, this mechanism is designed to ensure that people can sleep undisturbed even in noisy environments. This mechanism works with the usual and slightly different soundscape, but not with strong acoustic stimuli.
Interestingly, this muffled state is interrupted several times per minute for one to two seconds, so that the brain can react normally to sounds for a short time. This is probably to check whether danger is imminent or whether it is possible to continue sleeping without any concern.

Source: from 4 September 2009

More creativity through dream sleep break

In the dream phases of sleep (REM sleep) not only information is processed, but also possible solutions for previously set tasks are found. The long-known assumption that dreams provoke creativity has now been confirmed by a study by psychologists Sara Mednick and Denise Cai from the Californian University of San Diego.

During the investigation, the test subjects were given various creative tasks. Thus, analogies to given words should be searched for and word sequences should also be formed.
The tasks were set and discussed in the morning, the solutions should then be answered after a two-hour lunch break. During this break it was observed whether the test persons noticed the offered midday sleep and whether they had REM sleep.

The final evaluation of the study showed that the subjects who had slept during the lunch break and fell into REM sleep were significantly more successful (creative) in the test.

The psychologists emphasized that the increased creativity came about through REM sleep independently of pure memory performance.

The head of the investigation, Sara Mednick assumes that by the challenge of the given task in the dream sleep (REM phase) new connections of the existing knowledge are tried out.

Source: / focus-online from 9 June 2009

New York, London: Bedbugs on the rise again

Bedbugs are back on. What we only knew as horror stories of fathers and grandfathers, e.g. that the bed feet were placed in cans filled with oil to be able to sleep undisturbed by the unpopular bloodsuckers, could also become the future for us again.
In New York and London, at least, bedbugs have re-established themselves in many old building apartments and cheap hotels.

According to BBC-online, more than 10,000 cases were reported in New York last year and the number of unreported cases is believed to be much higher.

The bugs are about 6 – 7 mm in size, they are nocturnal and hide in crevices and crevices during the day. At night they crawl out of the holes and find a host to suck their blood. According to Herbert Auer, head of the Institute for Hygiene and Medical Microbiology at the University of Vienna, the bite of a bug is harmless, because bugs do not transmit diseases. However, the stitches create unpleasant circular, itchy marks on the skin.

It is assumed that bugs, like many other parasites, have developed resistance through the massive use of pesticides, which make it difficult to control the animals.

The New York authorities are startled and want to get a grip on the problem as soon as possible. In addition to an information campaign, the trade in used mattresses is to be stopped.

Source: BBC online / presstext.austria 30.03.2009

Low pulse - short sleep

“Elephants are up 20 hours a day”
The basic rule: large animals with low heart rate and (relatively seen) low energy turnover sleep little, small animals with high heart rate and turnover much.
More precisely, the duration of sleep depends on the length of the blood vessels: the larger the blood vessels per kilogram of weight, the higher the pulse and the longer the sleep.
Heat loss also plays a role – small animals lose a lot of it. So sleep has something to do with energy supply. But it remains a mystery: Why is it not enough for small animals to rest when awake? “This would make it easier for them to recognize danger.”

Quote from “welt-online” from 08.07.200

Interesting approach to the function of sleep

Neuroscientists Giulio Tononi and Chiara Cirelli from the University of Wisconsin (Madison) presented a new theory at a Society for Neuroscience conference in Washington.

Until now it has been assumed that sleep is there to enable the brain to process the experiences of the day. Tonini and Cirelle now add an interesting and plausible addition:

They believe that the brain uses the night’s rest to generally loosen the connections between the nerve cells (synapses). If the nerve connections remained too tightly connected, they would take up too much space and too much energy and could therefore no longer process new impressions. The “global downregulation”, on the other hand, works like a small restart and prevents the nerve cells’ ability to learn from becoming saturated, so to speak.

In the waking state, according to Tonini and Cirelli, the brain builds up an ever stronger excitation and thus becomes increasingly sensitive and thus more dependent on stimulating stimuli, while in the asleep state, after a long deep sleep, the reaction to stimulation is much weaker. By attenuating the stimuli, the brain is given a kind of openness and indeterminacy for the daily new beginning.
Source: Focus online from 21.11.2008

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