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| Posted : Nov, 2007 |
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Too little sleep not only makes you obese and anti-social, but also may be deadly |
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Sleep deprivation is a serious global phenomenon affecting a lot of people. |
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Sleep loss can impair the immune system and brain processes such as learning and memory. |
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| Hectic modern city lifestyles have led many people to squeeze their sleeping time down to a dangerously low level. A third of the people in the UK and over 40% Americans regularly sleep less than 5 hours a night (Source). Sleep deprivation is a serious global phenomenon affecting a large number of people. |
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| Lack of sleep upsets the body's internal clock, and disrupts every physiological function of the body. It affects crucial hormones and proteins that play important roles in diseases such as cancer, heart diseases and diabetes. Sleep loss can also impair the immune system and brain processes such as learning and memory. |
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| The bad consequences of insufficient sleep highlighted from a few recent studies: |
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A British research found that people with less than 5 hours of sleep are more than twice likely to die of heart disease, and have 1.7 times higher risks of dying from all causes. |
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Studies in the UK, France, Japan, Spain and the US showed that insufficient sleep is highly associated with obesity |
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A study in the US indicated that lack of sleep may be associated with antisocial and aggressive behaviour in adolescents and children. |
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A US study discovered that when healthy people are seriously deprived of sleep, their brain activities resemble certain pathological psychiatric patterns, and they show pendulum-swings in emotions. |
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People with less than 5 hours of sleep are more than twice likely to die of heart diseases. Photo: Open heart surgery |
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| I. Lack of sleep increases risks of dying from all causes, particularly of heart diseases |
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| The University of Warwick in the UK had conducted a 17-year analysis of 10,000 government workers to study the relationship between sleep patterns and mortality rates. The sleep patterns of participants aged 35 - 55 years were recorded at two points in their lives, in 1985-88 and 1992-93. Then their mortality rates were tracked until 2004. |
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| Researchers found that people with less than 5 hours of sleep are more than twice likely to die of heart diseases, and have 1.7 times higher risks of dying from all causes. (Related News: Sept 24, 2007) |
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| The exact reasons are not known. One possible explanation is that lack of sleep will result in increases in stress hormone and blood pressure, which are known to increase the risks of heart attacks and stokes. |
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| Other studies have found that sleep influences the functioning of the lining inside blood vessels, which may explain why people are most prone to heart attacks and strokes during early morning hours. |
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Insufficient sleep is one of the major factors leading to overweight and obesity in children and adults. |
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The link between short sleep duration and obesity is the most significant early on in life, where it may have the greatest impact on setting future eating habits. |
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Insufficient sleep upsets the hormones regulating appetite, and boosts the desire to crave for calorie rich foods. Photo: Fatty pork |
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| II. Insufficient sleep is highly associated with obesity in children and adults |
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| In a study by the University of Michigan in the US, researchers analysed the sleep patterns of 785 children aged 9 to 12. The key findings were: |
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The 12-year-olds sleeping less than 9 hours a day were more likely to be overweight than their peers with longer sleep. |
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Of the 9-year-olds who slept 10 to 12 hours a day, 12% were obese by 12 years old. For those who slept less than 9 hours a day, 22% were obese by 12 years old. |
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For the 9-year-olds, sleeping more than nine hours 45 minutes a day would lower the risk of becoming overweight later significantly. |
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| According to the National Sleep Foundation of the US, children in elementary schools should get 10 to 12 hours of sleep a night. The impact of shorter sleep was consistent in the above research regardless of gender, race, socioeconomic status or quality of the home environment. The research report was published in the Nov 2007 issue of the journal Pediatrics. (Related News: Nov 5, 2007) |
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| A UK study published in 2005 found that insufficient sleep in infants aged 30 months was associated with obesity by the time they reach 7 years old. This study was conducted by the Bristol University. (Related News: Oct 19, 2006) |
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| Other studies conducted in France, Japan, Spain, and the US also found significant links between short sleep duration and obesity in children and adults. (Source) |
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In a French study of 1,031 children aged five years, children sleeping less than 11 hours a night were significantly more obese. |
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In a Japanese study of 8,274 children, aged six to seven years, the obesity rate of those sleeping less than 8 hours a night was 3 times more than those sleeping 10 hours. |
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A Spanish study of 1,772 adolescents (15 years or older) reported an association between short sleep duration and obesity. |
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Using sleep data of 1.1 million adults from the American Cancer Society, it was found that short sleep duration was associated with obesity and mortality rates. |
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| Why insufficient sleep would increase appetite |
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| Two opposing hormones, ghrelin and leptin, are involved in regulating appetite. Ghrelin is a hormone released by the stomach to signal hunger. Leptin is a hormone produced by fat tissue to signal the state of fat stores. Low leptin and high ghrelin would signal an energy deficit to the hypothalamous in the brain. This results in hunger and an increase in appetite. |
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| In studies conducted by the Bristol University, it was found that adults sleeping only 5 hours a night had almost 15% higher levels of ghrelin, the hormone that signals hunger, than those sleeping 8 hours. These adults also had more than 15% less leptin. (Related News: Dec 20, 2004) |
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| Sleep loss also disturbs other hormones, including insulin, cortisol (stress hormone), and growth hormones. These hormonal changes may boost the desire for calorie rich foods. |
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| Poor sleep sets up a vicious cycle. It leads to fatigue, which in turn reduces the levels of physical activity and energy expenditure. This leads to obesity, which itself may lead to poor sleep. |
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Kids and adolescents with insufficient sleep have more aggressive and antisocial behaivours, and are more prone to substance abuse. |
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| III. More antisocial and aggressive behaviours among sleep-deprived adolescents and children |
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| In a research conducted by the Pennsylvania State University in the US, researchers found that sleep pattern is related to behavioural problems, such as antisocial and aggressive behaviours, among adolescents and children. Their study involved 113 participants between 8 to 13 years old. |
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| Those who prefer nighttime activities and stay up late often do not have enough sleep. Lack of sleep in turn causes problems such as lack of control and attention regulation, which are associated with antisocial behaviour and substance abuse. |
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| One possible explanation is that sleep deficit results in higher levels of cortisol, a stress hormone related to circadian rhythms. Previous studies showed that abnormalities in cortisol secretion are associated with clinical depression and antisocial behaviour. |
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| The research findings are published in the July 2007 issue of the journal Developmental Psychology. (Related News: July 20, 2007) |
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The brain activities of seriously sleep-deprived people resemble certain pathological psychiatric patterns. Photo: MRI scan. |
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| IV. Emotions run amok in healthy but seriously sleep-deprived people, resembling psychiatric disorder |
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| In a US study conducted by the University of California Berkeley and Harvard Medical School, researchers discovered that when healthy people are seriously deprived of sleep, their brain activities resemble certain pathological psychiatric patterns. |
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| The study involved 26 young, healthy adult volunteers. Half of them were kept wake for around 35 hours, while the other half slept as normal. Their brain activities were scanned in real time by functional magnetic resonance imaging (MRI) while they viewed 100 images, starting from emotionally neutral to increasingly negative ones. |
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| It was found that those who stayed up showed significant shifting of brain activities from the rational centre (in prefrontal cortex) to the fear centre of "fright, flight, or fight" (in amygdala). They became more than 60% more reactive to negative emotional stimuli. Their emotions seemed to swing like a pendulum. |
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| Traditionally, it was thought that psychiatric disorders resulted in sleep abnormalities. However, it may be the other way round. Even healthy people's brains mimic certain pathological psychiatric patterns when deprived of sleep. |
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| The research report was published in the Oct 23, 2007 issue of the journal Current Biology. (Related News: Oct 24, 2007 - Live Science; Reuters) |
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Sleeping when tired is a basic instinct in all animals. Enjoying a good sleep is one of the most basic human rights, the one which is often ignored. |
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| The most un-intelligent behaviour from the most intelligent species on earth |
| : Self-inflicted sleep deprivation |
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| Sleeping when tired is a basic instinct in all animals. Human beings are one of the few species that deliberately deprive themselves of sleep, often irrationally and unnecessarily. It is a real oddity in nature. |
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| As the society becomes so called more civilized due to the advancement of technology and innovations, the living qualities of many people actually head in the opposite direction. A large portion of people are sleeping less than 6 or even 5 hours per night, making them mentally and physically crippled. |
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| Late night movies, surfing the internet, video games, real-time World Cup football matches ...... a long list of night time entertainments is keeping people busy 24-hours round the clock. The intense pressure from hectic city life, heavy work loads, studying pressure and relationship problems etc. contribute to sleeping problems for a large majority of the population. |
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| Modern city lifestyle with materialistic comfort quite often comes with an expensive cost -- sleepless nights. It is time to revisit our priorities, and treat ourselves in a more humane way. Simply go to bed according to our natural internal clock -- it is one of the most basic human rights, the one which is often ignored. |
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