Sunday, October 19, 2014

Five common sleep myths

This article busts five common myths about sleep.

Good sleep is a cornerstone of good health. Yet misunderstandings about sleep – and lack thereof – are common. Here experts shine a light on five popular myths about sleep.

1. Older people don't need as much sleep as they used to.

Older woman in bed alseep
Fact: The amount of sleep adults need remains fairly stable from about age 20 onwards.
You've probably heard you'll need less sleep as you age. So when older people spend hours awake in the middle of night or wake before the sun comes up, it's often accepted as a normal part of ageing.
But while some aspects of sleep do change as you age, the amount of sleep you need remains fairly constant, says Professor David Hillman, chair of the Sleep Health Foundation.
"If people notice a change in their sleep requirements as they get older, such as spending longer in bed for less benefit, and waking up unrefreshed despite getting the same amount of sleep that used to refresh them, then that implies there's something wrong with sleep itself," he says. In this case, he advises seeing a sleep specialist who can help to diagnose any possible sleep disorder and once these are identified and treated, older adults can feel years younger.
You are also more likely to experience advanced sleep phase syndrome as you get older, which means you get sleepier earlier in the evening, Hillman says. So while you may still be sleeping for eight hours, you might find yourself awake before the birds.
Also, while your body is programmed to sleep at night, some of us find ourselves feeling sleepy in the afternoon. Given that older adults are less likely to be at work, they sometimes have an afternoon nap. But napping in the afternoon, especially later in the afternoon, will affect how well you sleep at night.

2. You can die from lack of sleep.

Man lying in bed looking worried
Fact: Possibly, but it's more likely due to an increased risk of accidental death.
While sleep is important to human health, there's no good evidence to show being sleep deprived has direct and profoundly deadly effects on your body, says Sydney sleep researcher Dr Nathaniel Marshall. But it can impair your judgement in potentially fatal ways.
"People are just more likely to do stupid things and put themselves in life threatening situations when they've not been sleeping," Marshall says.
American high school student Randy Gardner, who stayed awake for 11 days, is regarded as the record holder for the longest period going without sleep. He did not use stimulants, but rather kept himself awake by doing things he found fun, like playing basketball, Marshall says.
At the conclusion of the attempt, Gardner's health seemed good; he was able to speak, play games and do limited mental tasks. When he finally slept, he did so for just 14 hours and 40 minutes, awoke naturally, stayed awake 24 hours, then slept a normal eight hours.
"This kid showed that you can stay awake a long time and it's not fatal. I mean I'm not recommending it – he was a special case and he had experts supervising him – but it's not fatal. He just slept for 14 hours."
However Marshall points out the effect of Gardner's experience on his health was not examined in any detail in the experiment.

3. If you're not a morning person, you never will be.

Man yawning under the covers in bed
Fact: Your internal 'body clock' is not rigidly fixed but is influenced by your sleep routine.
Feel like you'd rather die than get up when your alarm goes off in the mornings?
The time we feel sleepy and the time we wake up is influenced to a large extent by an internal clock in the brain that varies from person to person. It's true that some of us are more 'early to bed and early to rise' people than others. But despite what many of us think, our internal body clocks are not rigidly fixed, says Sydney sleep physician and researcher Dr Keith Wong. They are partly determined by our genes but also by our sleep routine, he says.
If you want to become more of a 'morning person', he advises changing the time you get up, rather than the time you go to sleep, as this will have the most impact. Try pushing back your wake time a small amount each day and expose yourself to bright light soon after waking, to 'reset' your clock's 'programmed' wake time. (Daylight is best, as even the natural light on a cloudy morning is brighter than most artificial light.) Go to bed when you feel sleepy, and avoid bright light in the evening before bed. Once your body clock is set to your new routine, you'll need to stick to a regular schedule to maintain it.
If you cannot go to sleep until very late at night and lifestyle change doesn't help, you may have a condition known as Delayed Sleep Phase Syndrome, where the internal clock does not work properly. More complex treatment from a sleep specialist may be needed to treat this.

4. People who get up early are healthier.

Woman sleeping in bed
Fact: Getting enough sleep is more important than the time you get up.
Getting up early has a lot going for it. The world tends to be quieter and less crowded, and the first rays of daylight can be golden and beautiful. But there's nothing inherently healthier about being an early riser, says Sydney sleep physician and researcher Dr Keith Wong.
A 1998 study of more than 1200 adults published in the British Medical Journal could find no health advantages in the 'early to bed, early to rise' habit. So if you're not someone who wants or needs to get up early, don't feel compelled to do so, Wong says.
But while when you sleep is not important, how much you sleep is. Not getting enough sleep can impair your reaction time, problem solving ability, mood and immune system. And it might lead to long term health problems, such as heart disease and diabetes.
Being an early riser could have health advantages if it means you're less likely to be forced to undersleep to fit in with the schedule you are expected to keep, for example, the hours you work or study. A standard nine to five business day for instance is more suited to someone who tends to wake when the sun comes up than someone who likes to sleep until mid morning or later. But being a late riser is probably better if you are a musician or chef who needs to work until later at night and still wants to be sure to get enough zeds.

5. Counting sheep will help you fall asleep.

Woman in bed looking at an alarm clock
Fact: Mental imagery can help induce sleep but the task has to be something you find pleasant and relaxing.
Counting sheep has long been touted as a way of combating insomnia; references to the practice in literature date back more than 150 years. But whether it works has never been tested in scientific studies.
It's known though mental imagery can help bring on sleep by serving as a distraction from stressful thoughts, says Sydney sleep psychologist Dianne Richards. But what works for some may not work for others. It needs to be something you find pleasant and relaxing and her experience is that many people find counting tasks somewhat stressful. Her hunch is that other methods will have broader appeal.
The idea behind distraction strategies is to stop your mind worrying, planning or problem solving as these are activities that lead to production of the stress hormone cortisol and interfere with sleep.
But if the alternative task you give your brain is too boring, or it simply doesn't appeal, you won't stick with it and your mind will drift back to the thoughts that produce cortisol.
"Ultimately, the task you choose has to be effective for you," she says.
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