By Amanda Ursell, Bsc Nutrition, Dip Dietetics at healthyfood.com
The science: Sleep patterns
If you've lost the ability to switch off, don't worry, you can reset your sleep pattern. First, it helps to understand the nightly cycles.
Sleep quality has the biggest influence over our wellbeing and happiness – more so than income, exercise, sex and social connections. A recent Oxford Economics study found a good night's kip was the equivalent of having four times more disposable income, in terms of boosting our wellbeing. That's worth taking notice of.
We spend approximately one-third of our lives asleep. This is more time than we spend looking after our children, socialising or working. Yet, we tend to take sleep for granted – thinking of it as a revitalising process that just happens.
After all, it's a gift we're born with – when babies need to sleep they merely close their eyes and drift off. But, by the time we reach adulthood, we've been taught to regulate our sleep habits according to the customs of our society. This learned behaviour supplants our ability to sleep naturally.
As we grow we inevitably experience stress, daily or sudden. If we're lucky, any bad effect on our sleep is temporary but, sometimes, stress might cause long-term sleep problems. The good news is you can relearn how to sleep well, just as you originally learned your sleep pattern as a baby.
How much do you get?
First, there's no such thing as a night of uninterrupted sleep. On average, we clock up between six and nine hours of sleep a night, in four or five separate cycles, each lasting roughly 90 minutes. These cycles are interspersed with brief periods of wakefulness, which we don't remember. To further complicate matters, each sleep cycle has five stages: drowsiness, light sleep, two stages of deep sleep, and REM sleep (more on that later). A healthy adult's sleep comprises around 25 per cent deep sleep, 50 per cent light sleep and 25 per cent REM.
In our society we tend to sleep in a 'monophasic' pattern – a single period every 24 hours, occurring during the night. There are no rules about how much we need. If you only stack up four or five hours but feel well the next day (and are able to cope without relying on stimulants or naps), there's no need to worry – a few people are simply built that way. Similarly, while sleeping more than nine hours a day is rare, it's not cause for concern unless social factors (such as work or study) are affected. Watch for changing sleep patterns, though. If you suddenly find you need to sleep far more than is normal for you, it's worth checking whether there's an underlying health issue.
These days, there are apps and devices that track your sleep fairly accurately. But, remember, they're just a guide and shouldn't cause you more stress! If you can answer yes to these three questions, you're probably getting enough sleep:
• Do you fall asleep in under 20 minutes?
• Do you sleep right through without being aware of waking in the night?
• Do you wake up in the morning bright and alert?
And if you can't answer yes? There's no single solution, because everyone's different. But here are a few key insights and techniques, to start you off on the journey to restful slumber.
Falling asleep
To fall asleep easily we rely on our brain to switch off our wakefulness controls and, at the same time, activate our sleep centres. In people who are not stressed, have not been overly active before they go to bed and who are without sleep problems, this process is automatic. We enter stage 1 of sleep, our muscles relax and our eyes roll back. But if, for example, we're stressed, our wakefulness controls tell our brain our muscles aren't in the appropriate condition for sleep. This conflict will only be resolved once we start to relax.
Think back over the past week – how quickly did you drop off each night? You probably fell asleep almost immediately some nights, taking longer on others. In the first instance, you would have felt a rapid progression from wakefulness to feeling drowsy and then into light sleep. When you were having difficulty falling asleep, however, you would have drifted in and out of consciousness and your final loss of awareness – the moment when you actually crossed the threshold into sleep – probably seemed to take for ever.
At such times, when our brains appear to hover on the edge of awareness, many of us experience weird, dreamlike visions. These fragmentary images occur in a state known as hypnagogia and are characteristic of stage 1 sleep. Some people find them so alarming they, in turn, cause sleeplessness. More rarely, similar experiences occur as we drift into wakefulness – this experience is known as hypnopompia.
Although we can't control hypnagogia, it can help to know that it's a completely normal part of the falling-asleep process, and that any other apparently random experiences (for example, images of a loved one laughing, 'hearing' the sounds of alarm bells, and the common sensation of falling) are merely our imagination playing tricks on us. Perhaps, more romantically, we may like to think of the visions as temptations from the dreamworld, inviting us to come on in.
The sleep stages
Assuming we average eight hours of sleep per night, we spend roughly 50 per cent of this time in light sleep – that is, mostly stage 2. Periodically, we fleetingly return to stage 1, characterised by a change in sleeping position (although it's rarely significant enough for us to recollect having drifted into near-wakefulness).
A healthy person usually moves out of stage 2 and into deeper stage 3 sleep within 10-15 minutes. Stage 3 is brief – as soon as our brain waves have slowed down to comprise more than 50 per cent delta waves (high-voltage waves, oscillating at a rate of around one wave per second), we reach stage 4 sleep – the deepest level of all. This stage is most important for our overall wellbeing, which is why it takes precedence – the first third of our sleep is mostly made up of stage 4, but the duration of each period of stage 4 becomes shorter as the night wears on.
Stage 5 – REM (rapid eye movement sleep – so called because our eyes dart back and forth beneath the lids), or the 'dreaming phase' – is usually seen as distinct from the other four stages because this is when our brain is highly active and the brain waves resemble those shown during wakefulness. Having progressed through stages 1 to 4, we usually return to stage 2 before entering REM sleep. Typically, we spend more time in each sleep cycle in the REM stage during the second half of the night.
Repaying the sleep debt
Experiments have shown that if we're deprived of sleep for one night we usually make up most of the lost deep sleep the following night (usually at the expense of lighter sleep). If we're made to go longer without sleep – say, for two or more nights – practically the entire deep-sleep debt is recouped over the next two or more nights.
Similarly, when the sleep patterns of constitutionally short-sleepers (between four and five hours each night) are compared with constitutionally long-sleepers (those who need around nine or more hours of sleep to feel well), it is apparent that both types spend approximately the same amount of time in deep sleep – around two hours in total per night. Sleeping too little only becomes a problem when your lifestyle habits don't allow you to 'catch up' properly on your sleep, or when you consistently get too little and lack energy.
If deep sleep is the most essential stage, and our bodies are programmed to ensure that we can make up any deficit, we may wonder why we still feel unrefreshed and tired on any given morning. The answer is that, although deep sleep is the most important for our physical wellbeing (crucial body maintenance and repair is done during deep sleep), our waking sense of wellbeing arises from learned feelings of wellness, usually requiring us to have had complete, uninterrupted sleep, comprising all sleep stages.
In particular, we know that REM sleep plays a profound role in our physical and emotional wellbeing. By depriving subjects of this dreaming sleep, scientists have proved we become irritable, vague, fatigued and our ability to remember things suffers.
How to check your sleep quality
Before attempting to improve our sleep, we should first establish which aspects of our lifestyle affect it. Only one-fifth of the world's population enjoys perfectly healthy, restorative sleep. At best, the rest of us find ourselves dropping off as we read, for example, and, at worst, suffer from a sleep disorder, such as insomnia or sleep apnoea.
Begin by assessing your energy levels. Do you wake up feeling groggy or heavy-headed? Do you feel sleepy (or worse, fall asleep) at inappropriate times, such as during a meeting or in front of the TV? Does your energy slump significantly after lunch? When you feel sleepy during the day, does the impulse feel almost uncontrollable? If the answer to most or all of these questions is yes, your sleep quality isn't as good as it could be. But don't worry – it's solvable!
Three main factors that affect sleep are your mental and physical health and the sleeping environment. Listed below are a series of statements to help you assess your lifestyle and overall wellbeing. Any you tick can impair your ability to sleep properly, and it's a good idea to prioritise these in starting on any sleep improvement programme. Then look at all the other areas and take steps to address those too.
Assess your mental health:
• I am quick to lose my temper or become irritable
• I laugh less than I used to
• I find it hard to concentrate
• I often feel on edge and tense
• I often feel sad or lonely
Assess your physical wellbeing:
• I exercise less than twice a week (a brisk walk of about 20 minutes counts as the smallest unit of exercise)
• I often feel lethargic or sluggish
• I drink more than the recommended number of alcohol units per week (no more than 10 standard drinks a week for women and 15 for men)
• I sometimes find it difficult to breathe
• I often suffer from muscular pain
Assess your sleeping environment:
• My mattress is lumpy/more than 10 years old
• My bedroom is too cold/hot and stuffy
• I have a computer/TV in my bedroom
• I have noisy neighbours/live on a busy street.
Monitor your progress in a journal by your bed by noting how long it takes to fall asleep (do this in the morning), how long and how well you sleep, and how you feel on waking.
The exercise link
It wouldn't be an exaggeration to say that some insomnia is caused simply because we don't move our bodies often or energetically enough during the day. If we lead a sedentary life, sitting at a desk all day or spending hours in a car, our movements become restricted and tension builds up in our muscles. This accumulated physical stress makes us restless and uneasy – the body simply can't relax into sleep.
This is the beginning of a cycle of sleeplessness. We can't sleep, so we lie awake worrying about the fact we can't sleep (compounding the problem by adding psychological stress), then we become even more tense, and so it goes on. However, there is a simple remedy, and it's called exercise!
Get moving
Don't forget, even exercise that doesn't require you to push your body to its limits, such as gentle stretching before bed, will help ease tension. Or incorporate exercise into your daily routine and stop the build-up of stresses before they accumulate. Use the stairs instead of the lift, walk more briskly to the bus stop, and so on. The important thing is to make a start.
Time it right
Physical exercise influences sleep by affecting the body's metabolic rate and temperature in much the same way diet does. The various metabolic and hormonal changes associated with vigorous exercise are stimulating and increase the body's temperature. However, sleep comes more easily when our temperature is decreasing so, if we wish to use exercise to enhance our sleep, it makes sense to finish any strenuous workouts by late afternoon. Early research shows that walking on a treadmill during the day promotes sleep that night, but only if undertaken at least five hours before bedtime. The state of relaxation we experience after exercising also helps us to obtain our full quota of deep sleep.
So how much exercise do we need to do to improve our sleep?
It's probably less than you think – three sessions of 20 minutes per week will do it, provided it's aerobic exercise, which boosts oxygen consumption and improves breathing and circulation. These health benefits will all help you sleep better.
Of course, if you're more active and want to exercise more, that's great – just avoid high-energy evening workouts.
Get a better bed time routine
In his book Why We Sleep, neuroscientist Matthew Walker refers to a 'silent sleep epidemic'. Professor Walker believes sleep loss contributes to the global problem of obesity by unbalancing the hormones that control appetite and satiety. He also sees inadequate sleep as a major health issue.
"Routinely under-sleeping demolishes your immune system." Professor Walker points to a higher risk of conditions including cancer, diabetes, Alzheimer's and cardiovascular disease, as well as psychiatric disorders. Key to getting better sleep, he says, is establishing a healthy routine:
Stick to a sleep schedule
Go to bed and wake up at the same time every day. Set an alarm for bed too, so you get into the habit of winding down at a set time.
Remove anything in the bedroom that may distract you from sleep
Such as TV, phone or computer, and turn the clock's face out of view.
Don't rely on weekends to 'catch up'
Sleeping in at the weekend will make it harder to wake early on Monday.
Skip the nightcap
Alcohol may help you relax initially, but it keeps you in the lighter stages of sleep and robs you of REM. You're also more likely to wake up in the middle of the night when the alcohol wears off.
Before bed
Settle your breathing
After a stressful day, 20 minutes before bedtime, use this exercise to banish tension. It will help you to establish slow and regular breathing for a good night's sleep.
1. Sit on a chair or yoga mat with your arms loose by your sides, eyes closed. Quieten your mind Focus on the rhythm of your breath for two to three minutes.
2. Inhaling gently, raise your arms slightly, cross them in front of your body and bring them up over your head, uncrossing them as you go. Now exhale and swoop your arms down to your sides again. The whole movement should be executed in one long, circular sweep. Repeat this movement four times.
3. Inhale and raise your arms outwards and upwards, fingertips touching above your head. Exhale as you lower your arms. Repeat this three times.
4. Inhale, stretching your arms out parallel in front of you. Keep them straight and raise them above your head. Exhale, lowering your arms.
Insomnia vs sleeplessness
Crucially, sleeplessness and insomnia are not the same thing.
Sleeplessness
This describes a condition that nearly everyone understands: a period of time when someone desires sleep but does not get it. This can occur during the day or night – for example, if someone tries to have a nap in the afternoon and is unable to go to sleep, or if a parent is woken by their child, then finds themselves unable to get back to sleep.
Tips to break the sleeplesness cycle:
• Don't sleep anywhere but in the bedroom
• Keep your bed as a place for sleep and sex only
• If you don't fall asleep within 20 minutes, get out of bed and do something else
• Return to bed once you feel sleepy (and get up again if necessary)
• Set your alarm to wake you up at the same time every day.
Insomnia
This occurs when someone who has previously been a good sleeper suffers from chronic sleeplessness (lasting several weeks at least). Insomnia is one of the most common sleep complaints, affecting 30 to 40 per cent of adults in any one year. Three types have been identified:
• Idiopathic insomnia, also known as childhood-onset insomnia, is a lifelong condition with no obvious trigger. It may be due to a fault with the sleep–wake centres in the brain.
• Sleep-state misperception is a rare, debilitating condition. EEG readings will show sufferers to be asleep, but the person subsequently claims they were awake (so they don't feel rested).
• Psychophysiological insomnia, also known as conditioned or learned insomnia, is the most common type, usually triggered by an event such as bereavement or job loss. Good sleep hygiene can help sufferers overcome it, particularly if they can deal with the underlying problem at the same time. Relaxation techniques, including breathing, meditation, massage and aromatherapy, can help to break the cycle of worry and insomnia.
• Try rearranging your bedroom or even moving into a different room. Conditioned insomniacs can associate the bed and, sometimes, the room with sleeplessness.
• Keeping a regular journal is great for pinpointing factors that might be exacerbating insomnia and revealing even small improvements.
• Your next step is to go back to basics: set regular times to go to bed and to get up. Avoid tobacco, alcohol and caffeine and ensure the bedroom is light-proof and your bed is conducive to restful sleep.
Diet habits standing between you and a good night's sleep
How and what we eat affects our sleep patterns, explains nutritionist Amanda Ursell.
We all feel better and more energised after a good night's rest. Consistently poor sleep does the opposite and can lead to a range of health issues. As well as raising our risk of type 2 diabetes and Alzheimer's disease, it can also lead to diminishing mood and mental capabilities, and increased levels of the steroid hormone cortisol, which the body releases in times of stress. Poor quality sleep can also accelerate the physical signs of premature ageing.
The effects of tiredness on appetite
Scientists have found that lack of sleep can reduce the level of the appetite-controlling hormone leptin and increase the hormone ghrelin, which stimulates our desire to eat. The combination can lead to weight gain which, in turn, increases our risk of sleep apnoea and snoring – two problems that play havoc with a good night's rest. Even 5–10 per cent weight loss can significantly improve airflow and help reduce the volume and frequency of snoring.
The importance of routine
Some sleep experts report that people who eat at regular times throughout the day have more regular sleep habits. Since this is a good habit to get in to anyway, it's a pattern worth adopting.
Foods to help you nod off:
Milky drinks
A warm milky drink at bedtime is a time-honoured tradition to help us fall asleep. This idea is based on milk containing the protein building block tryptophan, an amino acid that has sleep-inducing effects.
In truth, one glass doesn't give us enough of this amino acid to have a sleep-inducing action. There is some, although limited, research to suggest that calcium, a mineral found in dairy and fortified alternative milks, is associated with ease of dropping off, with researchers suggesting this may be down to the mineral helping to lower blood pressure. The bottom line? If you find a warm mug of milk helps you to relax and drift off, keep having it.
Rice and pasta
You could try having a high glycaemic index (GI) carbohydrate with your evening meal. Scientists from the University of Sydney discovered that when men ate high-GI jasmine rice with their dinner, they fell asleep more easily than if they ate a low-GI rice. They speculate this may be down to high-GI carbs increasing the release of the calming brain chemical serotonin. Other high-GI carbohydrates include baked potatoes and couscous, which also may be worth a try.
Brazil nuts
These are among the richest dietary sources of the trace mineral selenium. Research reveals that, like calcium, less selenium in the diet is associated with more difficulty falling asleep and getting less so-called 'restorative' sleep. Aim for two to three nuts a day.
Chamomile tea
Long upheld as a remedy for a good night's sleep, chamomile contains a compound that has similar properties as anti-anxiety drugs that help us relax.
Those to avoid:
Caffeine in drinks and food
We all know by now that caffeine stimulates our nervous system and helps to keep us awake. For most of us, avoiding a cup of coffee, tea or a rich hot chocolate at bedtime is sensible advice.
The important thing to remember is just how long the breakdown of caffeine in the body takes, and to understand that the speed varies widely between different people. This means that, while avoiding caffeine for two to three hours may be sufficient to clear it from one person's system, for others it can take up to eight hours, which pretty much means you need to stop drinking caffeine-containing drinks from early afternoon to help promote good sleep.
To get an idea of how much caffeine is in those regular drinks, a cup of instant coffee has around 80mg caffeine and a cup of black tea around 60mg (or more if brewed for a long time). The amount in green tea is around 30mg per cup, while decaffeinated teas can still provide around 5mg a cup.
You can also expect to get around 26mg of caffeine in cans of regular and diet colas and around 32mg per 100mls in regular energy drinks (that's 160mg in a 500ml drink).
Check the ingredients on cold remedies and painkillers as, to perk you up, manufacturers may add caffeine, with some providing up to 65mg per tablet.
It is also worth knowing that a 50g bar of dark chocolate can provide 30mg caffeine, along with other potentially stimulating compounds. Stick to a small section of dark chocolate or switch to milk chocolate (10mg caffeine per 50g) if it's causing problems. Even chocolate and coffee ice creams can be sources of caffeine. In all cases, these treats are best avoided close to bedtime.
Booze
While alcohol may indeed help you to fall asleep, it goes on to disrupt the really beneficial restorative sleep, so it's best to avoid it before bed. If you do indulge, stick with one unit (a small glass of wine with a low alcohol content), one shot of spirits or a 250ml glass of lower-strength beer or lager.
Too many drinks
Having a small mug of warm milk or chamomile tea may be helpful, but too much fluid before bedtime will inevitably mean that you wake with a full bladder and need to nip to the loo, disturbing your sleep. Keep drinks small and go to the toilet just before you settle down.
Quick tips to help you get the best night's sleep
Don't lie in bed awake
If you find yourself still awake after staying in bed for more than 20 minutes, or if you're starting to feel anxious or worried, get up and do something relaxing until you feel sleepy. The anxiety of not being able to sleep can make it harder to fall asleep.
Don't take naps after 3pm
Napping can help make up for lost sleep, but leaving it until late afternoon can make it harder to fall asleep at night.
Daylight is key in regulating daily sleep patterns
Sleep experts recommend an hour's (sun smart) exposure to morning sunlight. If that's not possible, aim for at least 30 minutes exposure each day. If you can, wake up with the sun or use bright lights in the morning and turn down the lights before bedtime.
Get the right amount of sleep
For most adults 7-9 hours of sleep a night is recommended, although for over-65 year olds, that's 7-8 hours.
This article was originally published in the Healthy Food Guide and is republished with permission.