By Dr Aric Sigman on 11th September 2010
We must prevent children under three from watching television or risk irreversibly damaging their health.
It may sound shocking but, rest assured, far from being a Luddite, I am enjoying my brand-new iMac and we own a television set. However, I stopped my three youngest children watching TV before the age of three. Let me explain why...
We must prevent children under three from watching television or risk irreversibly damaging their health.
It may sound shocking but, rest assured, far from being a Luddite, I am enjoying my brand-new iMac and we own a television set. However, I stopped my three youngest children watching TV before the age of three. Let me explain why...
Over the past ten years I have been collating data and my discoveries have troubled me greatly – both as a biologist and as a parent.
Last month, I presented my findings to MEPs in Brussels. My message was unequivocal.
Last month, I presented my findings to MEPs in Brussels. My message was unequivocal.
There needs to be a recommended daily allowance for screen time as we have with salt and fat, or we risk harming our children when at their most vulnerable. Indeed, in 2008 the French government outlawed programming aimed at children under three.
Research suggests it is not what you watch, it is what age you start and how long you watch for that has a detrimental effect. In many ways Teletubbies, or any other educational programme for children, could be as physiologically damaging as a violent video game.
So, how does watching something on a screen – whether TV, a DVD, computer games or surfing the internet – have a negative impact, more so than other sedentary activities such as reading or knitting?
It is because we are instinctively transfixed by television. It elicits the orienting response – our sensitivity to movement and sudden changes in vision or sound. Studies have shown that infants, when lying on their backs on the floor, will crane their necks around 180 degrees to watch. Our attraction to looking at anything bright and fastmoving is an evolutionary mechanism, a survival instinct.
These images on screen trigger what psychologists call attentional inertia – we are dazzled and cannot take our eyes off the screen. The same behaviour is seen in some animals.
But it seems we pay the price for tapping into these primitive urges. Scientists have observed effects ranging from the immediate release of hormones into the blood, which can contribute to long-term health problems, to actual physical changes in the brain and learning disorders.
Research suggests it is not what you watch, it is what age you start and how long you watch for that has a detrimental effect. In many ways Teletubbies, or any other educational programme for children, could be as physiologically damaging as a violent video game.
So, how does watching something on a screen – whether TV, a DVD, computer games or surfing the internet – have a negative impact, more so than other sedentary activities such as reading or knitting?
It is because we are instinctively transfixed by television. It elicits the orienting response – our sensitivity to movement and sudden changes in vision or sound. Studies have shown that infants, when lying on their backs on the floor, will crane their necks around 180 degrees to watch. Our attraction to looking at anything bright and fastmoving is an evolutionary mechanism, a survival instinct.
These images on screen trigger what psychologists call attentional inertia – we are dazzled and cannot take our eyes off the screen. The same behaviour is seen in some animals.
But it seems we pay the price for tapping into these primitive urges. Scientists have observed effects ranging from the immediate release of hormones into the blood, which can contribute to long-term health problems, to actual physical changes in the brain and learning disorders.
A study from the University of Florence in 2006 of children aged six to 13 who spent an average amount of time watching TV found that their levels of melatonin – a hormone that causes us to sleep, but is also important for a healthy immune system and regulating the onset of puberty – shot up by 30 per cent after one week with no screen time.
If TV does suppress melatonin release, could this explain why puberty now begins in girls, on average, aged nine years 10 months – a year earlier than two decades ago?
Hormones related to metabolism are also affected. A study at the University of Sydney published this summer found that of a group of 290 boys aged 15, those who watched TV or DVDs or played computer games for more than two hours a day had elevated levels of chemical markers related to the development of coronary heart disease in later life.
And this year the University of Copenhagen found that individuals given 45 minutes of computer screen time subsequently consumed 230 calories more from a buffet than those who were given no stimulus.
These findings were backed up by a study from Birmingham University that found women who watched TV during a meal were likely to snack more in the hours after. One theory is that screen time interrupts the release of chemicals in the blood linked to hunger and satiation. Or perhaps memory is affected, so we forget we have eaten.
Perhaps the most compelling study, from the Dunedin School of Medicine, New Zealand, was published in 2004. Researchers followed 1,000 individuals from early childhood, for 26 years. They found that those who watched more than two hours a day between the ages of five and 15 were 15 per cent more likely to have raised blood cholesterol.
This link remained, irrespective of other factors such as social background, body mass index (BMI) at age five, parents' BMI, parental smoking and how physically active the children were by the age of 15. Those that did not watch TV did not have any raised health risks.
If TV does suppress melatonin release, could this explain why puberty now begins in girls, on average, aged nine years 10 months – a year earlier than two decades ago?
Hormones related to metabolism are also affected. A study at the University of Sydney published this summer found that of a group of 290 boys aged 15, those who watched TV or DVDs or played computer games for more than two hours a day had elevated levels of chemical markers related to the development of coronary heart disease in later life.
And this year the University of Copenhagen found that individuals given 45 minutes of computer screen time subsequently consumed 230 calories more from a buffet than those who were given no stimulus.
These findings were backed up by a study from Birmingham University that found women who watched TV during a meal were likely to snack more in the hours after. One theory is that screen time interrupts the release of chemicals in the blood linked to hunger and satiation. Or perhaps memory is affected, so we forget we have eaten.
Perhaps the most compelling study, from the Dunedin School of Medicine, New Zealand, was published in 2004. Researchers followed 1,000 individuals from early childhood, for 26 years. They found that those who watched more than two hours a day between the ages of five and 15 were 15 per cent more likely to have raised blood cholesterol.
This link remained, irrespective of other factors such as social background, body mass index (BMI) at age five, parents' BMI, parental smoking and how physically active the children were by the age of 15. Those that did not watch TV did not have any raised health risks.
Screen time also triggers the release of dopamine, a brain chemical that is involved in learning and concentration. When we see or experience something new, dopamine is released in the brain. Its effect is to focus our attention.
The surges caused by regular screen time may mean the brain becomes desensitised, so when the child later has to concentrate on something that does not have the same hyper-stimulating effect – a book or a teacher – they find they cannot do so. It's a bit like the way that those who add salt to their food find unsalted food tastes dull.
About 80 per cent of brain development happens before we are three, and screen time at this age seems to be particularly damaging.
At the other end of the spectrum, a study this year from the Heart and Diabetes Institute, Melbourne, found that each daily hour of TV viewing in adulthood was associated with an 18 per cent increase in death from heart disease. Those who watched four or more hours were 80 per cent more likely to suffer a fatal heart condition.
By the age of 75 the average Briton will have spent more than 12 years watching television. Those aged 11 to 15 now spend 50 per cent of their waking lives – 42 hours a week, six hours a day – in front of a screen.
The good news? If you turn the TV off these ill-effects can be prevented or reversed. After all, there are no health risks to reading a good book.
Retrieved from: http://www.dailymail.co.uk/health/article-1311139/Teletubbiesbad-child-violent-video-games.html#ixzz16jtWofId
The surges caused by regular screen time may mean the brain becomes desensitised, so when the child later has to concentrate on something that does not have the same hyper-stimulating effect – a book or a teacher – they find they cannot do so. It's a bit like the way that those who add salt to their food find unsalted food tastes dull.
About 80 per cent of brain development happens before we are three, and screen time at this age seems to be particularly damaging.
At the other end of the spectrum, a study this year from the Heart and Diabetes Institute, Melbourne, found that each daily hour of TV viewing in adulthood was associated with an 18 per cent increase in death from heart disease. Those who watched four or more hours were 80 per cent more likely to suffer a fatal heart condition.
By the age of 75 the average Briton will have spent more than 12 years watching television. Those aged 11 to 15 now spend 50 per cent of their waking lives – 42 hours a week, six hours a day – in front of a screen.
The good news? If you turn the TV off these ill-effects can be prevented or reversed. After all, there are no health risks to reading a good book.
Retrieved from: http://www.dailymail.co.uk/health/article-1311139/Teletubbiesbad-child-violent-video-games.html#ixzz16jtWofId
