Sleep – How Important is it for our Health?
“I would consider sleep to be a key element for our wellbeing. Lack of sleep can affect our mood; our ability to make the best food choices; our ability to focus and work efficiently; our motivation and energy to exercise and so the list goes on.”
I read two articles which had slightly different views on the subject. One “What sleep deprivation is really doing to your health” and another The “Myth of the eight-hour sleep”. The first highlighted all the concerns with our long term health if we are deprived of sleep and the second gives some reassurance or another perspective on what is ‘ a good night’s sleep’.
Sleep Deprivation: The first article discussed how chronic sleep deprivation can harm health as parts of the brain (the locus coeruleus – responsible for cognitive functions such as alertness and attention) are damaged. During sleep the brain cleans itself clearing out the rubbish it accumulated during the day – but if it is active for too long it can not clear itself and proteins gather. The worry is that if one was too ‘chronically’ push the system and stay awake for long periods of time one would have proteins gathering onto proteins and develop into what might be seen in Alzheimer’s or Parkinson’s. The article continues to discuss this issue in more depth and has some very helpful tools and ideas from Andy Puddicombe who is a former monk and meditation expert: Beditation: the key to sleep success.
The Myth of the Eight-hour Sleep: The second article discussed how we often worry about lying awake in the middle of the night and how a growing body of evidence from both science and history suggests that the eight-hour sleep may be unnatural. A historian Roger Ekrich published a seminal paper revealing a wealth of historical evidence that humans used to sleep in two distinct chunks. He believes that many sleeping problems may have roots in the human body’s natural preference for segmented sleep, and that this could be the root of a condition called sleep maintenance insomnia; where people wake during the night and have trouble getting back to sleep. The idea that we must sleep in a consolidated block could be damaging, Ekrich says, if it makes people who wake up in the night anxious, as this anxiety can itself prohibit sleep and is likely to seep into waking life too.
The stages of sleep: Every 60-100 minutes we go through a cycle of four stages of sleep. Stage 1 is a drowsy, relaxed state between being awake and sleeping – breathing slows, muscles relax, heart rate drops. Stage 2 is slightly deeper sleep – you may feel awake and this means that, on many nights, you may be asleep and not know it. Stage 3 and Stage 4, or Deep Sleep – it is very hard to wake up from deep sleep because this is when there is the lowest amount of activity in your body After Deep Sleep, we go back to Stage 2 for a few minutes, and then enter Dream Sleep – also called REM (rapid eye movement) sleep – which, as its name suggests, is when you dream. In a full sleep cycle, a person goes through all the stages of sleep from one to four, then back down through stages three and two, before entering dream sleep (Source: Gregg Jacobs).
How to Get a Good Night’s Sleep: Another article focused on the importance of a sleep routine; adult brains and bodies function better with one. Not having set bedtimes and wake-times can disrupt the delicate internal clocks that govern everything from our heart health to our weight and our risk of getting diseases such as cancer and diabetes.
Grown-ups need a proper bedtime. Its not how many hours you get that counts, say experts, but what time you fall asleep (Rachel Carlyle March 11 2017,The Times) We obsess about whether we’re getting enough sleep, but research is beginning to show that we might be missing the point; going to bed and getting up at the same time every day may be more important than getting a full eight hours. It’s not just babies and small children who need a sleep routine; adult brains and bodies function better with one too. Not having set bedtimes and wake-times can disrupt the delicate internal clocks that govern everything from our heart health to our weight and our risk of getting diseases such as cancer and diabetes. That’s why, even after pulling a late one on Saturday night, it’s better to spring up at the normal weekday time than to lie in bed, gently moaning, until 11am. The body craves routine it would love to go to bed and get up at the same time every single day, says Dr Neil Stanley, an independent sleep expert who has researched sleep patterns for 35 years. With a proper bedtime, you’ll have better sleep.
If your body is expecting to go to sleep at 11pm, and you begin getting ready for bed 30 minutes before, you’ll go to sleep more quickly because your body is expecting the cues. Thats why some people swear Horlicks helps them sleep, says Dr Stanley. Its nothing to do with a magic ingredient in the drink, but its the 30-minute ritual of getting it ready and drinking it that signals to your body it will be going to bed soon. Others swear by camomile tea, which has been found to have a calming effect, temporarily slowing memory and attention speed, according to a recent study at the University of Northumbria. When it comes to getting up, the brain also wants to be forewarned. Research has found that the body and brain make preparations for waking up 90 minutes before we actually wake up, says Dr Stanley. So if it knows what time that will be, it can squeeze as much goodquality sleep into that time as it can, regardless of the total number of hours. In fact, having a fixed wake-up time is probably the most powerful and effective change you can make to improve your sleep quality. The trouble with irregular sleep times is that they mess with our circadian rhythm, the body’s 24-hour clock, and create what scientists call social jet lag, where we lie in on a Sunday then can’t get to sleep that night because we have done nothing all day, and Mondays early-morning alarm makes us feel groggy. It doesn’t take much to throw out the rhythm; even the clocks going forward by an hour can take three days to get over you don’t feel hungry or tired at the right time and can feel out of sorts, says Dr Stanley. Research does not yet tell us exactly how much we can push the circadian envelope.
We tend to naturally get up at 7.18am, according to a 2015 survey by the Sleep Cycle app of its users aged 18 to 55, which is close to the perfect wake-up time of 7.22am, as defined by a University of Westminster study. However, the Sleep Cycle survey also reveals that most of us lie in bed at the weekend, getting up on average at 8.35am. Sleep scientists advocate changing your sleep patterns by no more than one hour from day to day, and Dr Stanley is in favour of a maximum lie-in of 30 to 45 minutes.
The dangers of disrupting your circadian rhythm are demonstrated at the extreme end in shift workers. Research has shown that they are more prone to obesity, diabetes, heart attacks, memory problems and early death. However, it may not just be shift workers in danger. This is an emerging area of science, and the evidence is showing that social jet lag is associated with weight gain, obesity and type 2 diabetes, says Professor Mary Carskadon, a world authority on circadian rhythms, from Brown University in Rhode Island. There’s interesting data emerging for example about the lining of the intestines showing long-term changes, and changes to bones, the kinds of things we never would have attributed to pushing our rhythms around. It seems the more we go away from a routine alignment, the more we march towards a path that can lead to illness. It’s too early to say how far you can push it, adds Professor Carskadon. Some people are resilient, but others are more vulnerable. The problem is, you don’t know which one you are.
Teenagers have a particular problem because the massive rewiring their brain undergoes from puberty pushes the production of melatonin, the sleep-inducing hormone, later in the evening, yet they need at least nine hours sleep a night which is hard to square with getting up for school.
They are losing so much sleep during the week they need to catch up at the weekend, so its like they are constantly jet-lagged, says Professor Carskadon. However, that doesn’t mean carte blanche to lie in, she emphasises. Research by her department has shown that, even when teenagers are given a modest lie-in until 9.30-10am, their circadian rhythm falls off course by 45 minutes over one weekend.
For younger children the situation is more clear-cut; they need regular bedtimes and waketimes to function properly. An Australian study of 2,000 children aged 5 to 10 showed that a child with a 60-minute difference in bedtimes across the week was twice as likely as those with the same bedtime to display hyperactive behaviour and have trouble controlling their emotions; children with a two-hour difference were six times as likely.
When choosing a bedtime its worth remembering that the first third of the nights sleep is the most important because it contains the highest levels of slow-wave sleep, the deep sleep that rejuvenates us. As it progresses through the night, sleep becomes less important and more flexible, particularly after six hours, says Jim Horne, emeritus professor of psychophysiology at the University of Loughborough. That doesn’t mean we can go to sleep at 2am every night and still get quality sleep. Our body clocks evolved at a time when natural light was the only synchroniser, so there is a bedtime window of between 8pm and midnight when the brain and body can get the right ratio of deep, non-REM sleep to REM (dream) sleep.
The best advice is to go to bed when you are sleepy and not to try to push through it. If you do that for a week, and fix a wake-up time for the same time every one of those days, you will get a sense of the right bedtime for you, says Dr Stanley. The average weekday bedtime in the UK is 11.45pm. The problem is that our 24/7 life and access to screens which suppress release of melatonin are conspiring to make us all a bit more owl-like (predisposed to going to bed late). This could be bad news for our health. A Finnish study of 2,000 people published last month found that ‘night-owls’ were more likely to eat high-sugar and fatty foods, take less exercise and sleep worse than larks (naturally early wakers).