Eight Hour Sleep May Be Unnatural

I've just read an interesting article on the BBC website saying that the eight hour sleep may be unnatural and that in the past, we used to sleep in two segments, often four hour stretches with a couple of hours in between

To quote 'We often worry about people who lie awake in the middle of the night - but it could be good for you. Scientists have been saying for 20 years that the eight-hour sleep may be unnatural, and historians increasingly are backing them up.'

Psychiatrist Thomas Wehr conducted an experiment in the early nineties, in which, for one month, a group of people were plunged into darkness for 14 hours every day.
Interestingly, by the fourth week, the subjects had settled into a pattern of sleeping for four hours, waking up for one or two hours and then going back to sleep for another four hours.
The theory that humans naturally slept in two distinct chunks has come up again, as historian Roger Ekirch at Virginia Tech undertook an intensive study into the human relationship with night, and found more than 500 references to a segmented sleeping pattern.

Sleep psychologist Gregg Jacobs says that waking up during the night is part of normal human physiology.
He says the idea that we must sleep in a consolidated block could be damaging, if it makes people who wake up at night anxious, as this anxiety can itself stop you from sleeping and is likely to trickle into your waking life too.

Source: BBC - Myth of the eight-hour sleep

Does Lack Of Sleep Make You Fat?

A study conducted previously and published in the American Journal of Clinical Nutrition by researchers Christian Benedict and Helgi Schiöth, of the Department of Neuroscience at Uppsala University, showed that a single night of total sleep loss in young normal weight men increased levels of hunger, which indicated that an acute lack of sleep may affect a person's food perception.

In a new study, the same researchers from Uppsala University, tried to isolate the part of the brain that was affected by acute sleep loss. They showed that a specific brain region that contributes to a person's appetite sensation is more activated in response to food images after one night of sleep loss than after one night of normal sleep. Poor sleep habits can therefore affect people's risk of becoming overweight in the long run.

Christian Benedict says, "After a night of total sleep loss, these males showed a high level of activation in an area of the brain that is involved in a desire to eat. Bearing in mind that insufficient sleep is a growing problem in modern society, our results may explain why poor sleep habits can affect people's risk to gain weight in the long run. It may therefore be important to sleep about eight hours every night to maintain a stable and healthy body weight."

This study only involved 12 normal weight men and it seems a bit of an extrapolation to conclude that this would be the case in everyone, male or female, overweight or of normal weight. What's more researchers compared the results after a night with normal sleep with those obtained after one night without sleep, not reduced sleep, so I'm not sure where they got the 8 hours sleep from...
However I do think that common sense dictates that when you haven't slept well, you are more susceptible to eating badly and thus gain weight if this happens regularly.

You Are More Likely To Have Insomnia If A Family Member Is An Insomniac

You are more likely to have insomnia if a family member is insomniac. This is according to a Study directed by Dr. Charles M. Morin of Université Laval's School of Psychology in Quebec City.

The research team found that the increased risk of insomnia is 67% higher in people from families in which at least one member is an insomniac.
The study involved 3,485 people and the participants were asked to answer questions on their sleep quality and that of their immediate families by telephone and then fill out questionnaire that they mailed in on three separate occasions in the following 12 months.
The analysed data showed that 40% of respondents came from a family that had at least one member who is an insomniac and the risk of suffering from insomnia increased according to the number of family members with insomnia.

Dr Charles Morin said that there is very probably a genetic factor behind the family aggregation observed but that we don't know if the mechanism is a physiological process that interferes with sleep or a predisposition to anxiety.
Certain attitudes towards insomnia by family members about not being able to fall asleep could also be involved and their negative experiences with insomnia could transform situational insomnia into a chronic condition.

He concludes by saying that the study conducted suggests that early psychological treatment could benefit people from families with chronic insomnia sufferers.

Learn Whilst You Sleep?

"There is substantial evidence that during sleep, your brain is processing information without your awareness and this ability may contribute to memory in a waking state" says Kimberly Fenn, assistant professor of psychology and lead researcher of a study conducted by Michigan State University researchers.

The study which was conducted by Fenn and Zach Hambrick, associate professor of psychology and used more than 250 people suggests that people derive vastly different effects from this sleep memory ability, with some memories improving dramatically and others not at all. This new, previously undefined form of memory is an unconscious form of memory that is still not properly understood means that people may be learning while they are sleeping.

"You and I could go to bed at the same time and get the same amount of sleep," Fenn said, "but while your memory may increase substantially, there may be no change in mine."
She did say however that most people showed improvement.

This is yet another study that reinforces the need for a good night's sleep and shows that whatever your age, gender, aspirations, you still function much better when you can fall asleep and have that deep refreshing sleep!

Rocking Helps You To fall Asleep

Researchers Sophie Schwartz, Michel Mühlethaler, and their colleagues Laurence Bayer and Irina Constantinescu from the University of Geneva, reporting in the June 21 issue of Current Biology, a Cell Press publication, now have evidence that napping on a slowly swinging bed really does get us to sleep faster.

To the researchers' surprise, rocking also changes the nature of our sleep, encouraging deeper sleep.

12 adult volunteers were asked to nap on a custom-made bed or "experimental hammock" that could either remain stationary or rock gently. All participants were good sleepers who didn't typically nap and did not suffer from excessive sleepiness during the day. Each participant took two 45-minute afternoon naps, one with the bed stationary and one with the bed in motion, while their brain activity was monitored by electroencephalogram (EEG).

A faster transition to sleep in each and every subject in the swinging condition, a result that supports the intuitive notion of facilitation of sleep associated with this rocking. Surprisingly, a dramatic boosting of certain types of sleep-related [brain wave] oscillations were also observed.

More specifically, rocking increased the duration of stage N2 sleep, a form of non-rapid eye movement sleep that normally occupies about half of a good night's sleep. The rocking bed also had a lasting effect on brain activity, increasing slow oscillations and bursts of activity known as sleep spindles. Those effects are consistent with a more synchronized neural activity characteristic of deeper sleep.

Schwartz and Mühlethaler say the next step is to find out whether rocking can improve longer periods of sleep and to find out whether it may be useful for the treatment of sleep disorders, such as insomnia.

Because sleep spindles have been associated with brain plasticity mechanisms, enhancing spindle activity with rocking may be good for memory consolidation and may even have the potential to improve brain repair mechanisms after brain damage.

Weekend Sleep Does Not Makeup For Lost Sleep In The Week

Performance deteriorates when sleep is restricted to six hours per night for a week and does not improve after two nights of recovery sleep, however, women may be less affected than men by this workweek pattern of sleep loss.

According to principal investigator Dr. Alexandros N. Vgontzas, professor of psychiatry and endowed chair in sleep disorders medicine at the Penn State College of Medicine and director of the Sleep Research and Treatment Center at the Penn State Milton S. Hershey Medical Center, after one workweek of mild sleep deprivation, two recovery nights did not improve performance even though it did improve sleepiness.

The study also found significant gender differences.  Compared with men, women were found to have less subjective sleepiness and less performance deterioration during sleep restriction, as well as greater improvements after recovery.  These differences were associated with increased amounts of slow-wave sleep, or “deep sleep,” in women at baseline.

“In women, but not in men, deep sleep appeared to have a protective effect,” said Vgontzas.  “Women with a higher amount of deep sleep can handle better the effects of one workweek of mild sleep deprivation, and their recovery is more complete after two nights of extended sleep.”

The study concluded that complete performance recovery after one workweek of mild sleep deprivation may require more than just two nights of extended sleep.

Less Sleep Can Make Children Fatter!

It seems that Sleep can make children fatter!

A team of researchers in New Zealand set out to investigate whether reduced sleep is associated with differences in body composition and the risk of becoming overweight in young children. The study was reported in the British Medical Journal.

They found that on average, children aged three to five sleep 11 hours a night, but for every hour they sleep less than that between the ages of three and five, they will be carrying an extra pound and a half of fat by their seventh birthday.
The results show that young children who sleep less are at a significantly increased risk of having a higher BMI by age 7, even after controlling for other risk factors that have been implicated in body weight gain.

According to the researchers, the reduced sleep may increase their food intake and may also make them exercise less.

So it is important for parents to ensure that growing children get enough sleep and adequate exercise.