A guide to good sleep and its health benefits
Studies have shown that chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including high blood pressure, cardiovascular disease, cancer, heart attack and Alzheimer’s as well as diabetes, depression, and obesity.
Sleep loss is estimated to cost the UK economy £30 billion a year in lost revenue – that’s 2% of GDP. Without sleep, there is low energy and disease. With sleep, there is vitality and health. After being awake for 19 hours, you are as cognitively impaired as someone who is drunk. Sleep also aids our ability to make new memories and restores our capacity for learning.
Sleep cycles range from 90 to 120 minutes, with 4 or 5 cycles during each night’s sleep. Typically, there is more “NonREM” or deep-sleep in the first half of the night and REM sleep in the later part.
REM – is the phase of sleep where you experience fast frequency and low voltage brain waves and inactivity of voluntary muscles in the body. Often reported as the dreaming stage of sleep. Roughly 20-25% of time asleep is in REM sleep. The importance of REM sleep is not fully understood, though some studies show that it is necessary for the brain to preserve memories and maintain neurological connections.
NREM – non-REM sleep occurs in 3 stages according to electrical activities:
N1 – transition from wakefulness to deeper sleep – light sleep, often people may not perceive they were asleep in this stage
N2 – a so called “true” sleep state 40-50% of the time
N3 – deep sleep or delta sleep – a slow wave about 20% for young adults
As we age the amount of N3 deep sleep declines, whilst light sleep N1 increases. Older people are more easily aroused from sleep when in the light sleep phases.
Feeling tired or drowsy at any time of day is a symptom of not having enough sleep. Being able to fall asleep within 5 minutes of lying down in the evening may also be a sign of sleep deprivation. Sleep deprived people perform poorly on tests like driving simulators and hand-eye coordination. Sleep deprivation can also magnify effects of alcohol. Caffeine cannot successfully overcome the drowsiness associated with sleep deprivation. There are over 70 types of sleep disorders, the most common are insomnia, sleep apnoea, restless legs syndrome and narcolepsy.
There is no fixed criteria that defines insomnia, although it is perceived as being poor-quality sleep including inability to fall or stay asleep. Sleep onset insomnia usually lasts for greater than 30 minutes, where sleep maintenance insomnia is when people awake for lengthy periods during the night (known as “Wake-after-sleep-onset” or WASO).
Sleep apnoea is the reduction of breathing airflow during sleep. Central sleep apnoea (CSA) occurs when the brain doesn’t send signal to the muscles to take a breath, and there is no muscular effort to take a breath. Obstructive sleep apnoea (OSA) occurs when the brain sends the message, but the muscles are unsuccessful because the airway is obstructed. Apnoea can be a mixture of CSA and OSA.
Medication can be of use, but typically medication has the potential for addiction, so must be carefully monitored by a health care practitioner. Typical prescribed medication may be any of a number of different types:
Non-benzodiazepine sedatives: zolpidem, eszopiclone, zaleplon (“the Zs”)
Ramelteon, which mimics the action of melatonin
Orexin receptor antagonists (“ORAs”) promote the natural transition from wakefulness to sleep by inhibiting wakeful promoting neurons (orexin) in the arousal system
Antidepressant medications have been used to treat insomnia in depressives
Tramadol, diazepam and temazepam (“the Pams”) and the like are used for restless leg syndrome
Nasal decongestants may provide relief for airway obstruction, but more usually a CPAP device (continuous positive airway pressure) is used for sleep apnoea
Anti-histamines can be used as a short-term treatment of insomnia, though they are not recommended for long term use
Melatonin has been tried in supplement form, and promoted as natural sleep remedy, however studies show it is generally ineffective in treating common insomnia, except specifically when patients have low levels of melatonin
What’s going on in the body and brain?
According to Matthew Walker, author of “Why we Sleep: The New Science of Sleep and Dreams” and professor of neuroscience at the University of California, when insomnia calls, his mind starts to race… “my orexin isn’t being turned off, the sensory gate of my thalamus is wedged open, my dorsolateral prefrontal cortex won’t shut down, and my melatonin surge won’t happen for another seven hours.“
A lack of sleep also appears to hijack the body’s effective control of blood sugar, the cells of the sleep-deprived appearing, in experiments, to become less responsive to insulin, and thus to cause a pre-diabetic state of hyperglycaemia. Moreover, when your sleep becomes short you are susceptible to weight gain. Among the reasons for this are the fact that inadequate sleep decreases levels of the satiety-signalling hormone, leptin, and increases levels of the hunger-signalling hormone, ghrelin. Walker says “Processed food and sedentary lifestyles do not adequately explain the rise of obesity. It’s now clear that sleep is that third ingredient.” Tiredness, of course, also affects motivation.
The Sleep Council advise that if night waking is a problem, sometimes it can be down to hunger. Typically, if an adult is waking around 3-4am, blood sugar has dropped which causes you to wake up and although you might not feel hungry, you may be. To ensure blood sugar is more balanced, try adding plenty of protein to dinner and go easy on the processed carbohydrates such as bread, pasta and rice (though brown rice and wholemeal pasta are ok). Other foods that help you sleep include carbohydrate sources such as sweet potatoes and other more starchy vegetables like carrots, parsnips and butternut squash. It can also be beneficial to have a pre-bed snack (about one hour before going to bed) such as berries and full fat yoghurt which help to prevent blood sugar dropping too low overnight.
Sleep has a powerful effect on the immune system, which is why, when we have flu, our first instinct is to go to bed: our body is trying to sleep itself well. Reduce sleep even for a single night, and your resilience is drastically reduced. If you are tired, you are more likely to catch a cold. The well-rested also respond better to the flu vaccine. More gravely, studies show that short sleep can affect our cancer-fighting immune cells. A number of epidemiological studies have reported that night-time shift work and the disruption to circadian sleep and rhythms that it causes increase the odds of developing cancers including breast, prostate, endometrium and colon.
Getting too little sleep across the adult lifespan will significantly raise your risk of developing Alzheimer’s disease. The reasons for this are difficult to summarise, but in essence it has to do with the amyloid deposits (a toxin protein) called plaques accumulate in the brains of those suffering from the disease, killing the surrounding cells. During deep sleep, on the other hand, such deposits are effectively cleaned from the brain. What occurs in an Alzheimer’s patient is a kind of vicious circle. Without sufficient sleep, these plaques build up, especially in the brain’s deep-sleep-generating regions, attacking and degrading them. The loss of deep sleep caused by this assault therefore lessens our ability to remove them from the brain at night.
In almost every diagnosis of a psychiatric disorder, we find that disturbance of sleep in some shape / form, is to be expected. Sleep is one of life’s most fundamental processes and when other things are knocked out of sorts, it is likely that sleep will be disrupted too. There is a strong relationship between sleep and mood. Insomnia or sleep deprivation affects us on both a physical and mental level, to name a few: fatigue; poor concentration; irritability. Insomnia can be a major risk factor for the development of a depressive illness and other psychiatric conditions.
CBT for insomnia is an evidence-based approach to treatment that looks at the relationship between the ways we think, feel and behave. Research has shown that CBT is an effective treatment for persistent insomnia. In addition to important strategies like sleep hygiene & relaxation, CBT examines the expectations that may get in the way of effective sleeping, therefore working with unhelpful thoughts that fuel the anxiety around sleep. CBT offers effective strategies to manage a racing mind and offers more self-help strategies to strengthen the connection between bed and sleep.
Non-medical treatment options are usually referred to as sleep hygiene.
This means the practice of behavioural habits that offer maximum potential for restorative and sound sleep. Good habits include:
Avoid caffeine, nicotine or alcohol use before bedtime
Have a regular bedtime and waking schedule
Relax before bed – try a warm bath, reading or a relaxing routine like mindfulness or other meditations, light a candle to lower the light levels
Maintain a comfortable sleep environment – including comfortable temperature
Avoid watching TV or using backlit screens in electronic devices and falling asleep with the TV on in the room
Do not lie in bed awake, worry about not sleeping or anything negative, which can produce anxiety making the problem worse. Do something like reading or listening to music until you feel tired
Get regular exercise (20-30 minutes a day) during the day (avoid exercise two hours before bedtime)