Dr Libby Artingstall & Dr Sile McDaid, Co-Founders & Directors Team Mental Health
Sleep: A non-negotiable necessity (Part 2)
It is difficult, given the current circumstances that we face during the COVID-19 pandemic, to think about making sleep a priority. However, now more than ever, good sleep is essential. Sleep offers great protection to our mental health and our immune systems, both vitally important at this time.
In our last blog, we introduced three key factors which influence our sleep patterns: Circadian rhythm (sleep / wake cycle); melatonin; and adenosine. To promote good sleep, it’s important for us to understand what positively and negatively affects these and consider what small changes we can all make to improve the quality of our sleep. Good sleep hygiene is key.
In his fascinating book ‘Why We Sleep’1, Matthew Walker (professor of neuroscience & psychology & director of the Centre for Human Sleep science at University California, Berkeley), highlights some features of the modern world which can negatively impact our sleep. Below, we have summarised a few important findings relevant to sleep hygiene, and encourage everyone reading this blog to think about the action they can take to improve their sleep:
Electric and LED Lighting:
Bright light and ‘blue light’, emitted from screens (televisions, laptops, tablets and smart phones), can significantly delay the release of melatonin and supress the amount of melatonin released. If this occurs, we are less likely to feel ready for bed at night-time and our sleep / wake cycle can be negatively affected. Therefore, we should avoid using screens for at least an hour before bed and keep screens out of the bedroom. If this is not possible, use ‘night-time mode’. In addition, we should try to avoid bright lights in the evenings and aim to get exposure to natural light in the mornings. Where possible, we should spend at least 30 minutes of the day in sunlight.
In the evenings, our core body temperature drops by approximately 1oC. Alongside the fading light, this temperature drop signals the natural release of melatonin. With the use of central heating, bedding and pyjamas we increase our core temperature, therefore the release of melatonin can be affected, and this may negatively impact our sleep. An ideal room for sleeping should be kept slightly cooler (the optimal temperature for adults is 18.3oC and where possible, pyjamas and bedding should be made from breathable fibres (for example, cotton). A warm bath can help to lower our core body temperature, so try this about an hour before bed. Strenuous exercise can increase our body temperature so this should be avoided for 3 hours before bed.
In today’s society, our sleep / wake cycle is often dictated to by ‘normal opening hours’. As such, it can be difficult not to use alarms to wake us from sleep. However, the use of an alarm to artificially terminate sleep can trigger the body’s ‘fight or flight’ response causing a release of stress hormones in our bodies. Chronic and prolonged activation of this stress response can have a negative impact on our mental and physical health, therefore where possible, we should try to avoid this. To increase our ability to wake naturally, we should implement a good sleep routine (with set bedtimes and wake up times). This enables our bodies to adjust and we can develop a good sleep pattern meaning that we should begin to wake naturally at a set time. Matthew Walker emphasises a good sleep routine as the number one priority to improve our sleep. In addition, we should avoid using the snooze button and get up once our alarm goes off. Not only will this help us establish a set wake up time, it will help us to reduce the number of times we ‘shock’ the body with stress hormones.
Caffeine is a drug that stimulates the release of adrenaline and inhibits adenosine. Adrenaline increases the body’s state of alertness and vigilance, thus improving our concentration and energy levels. Adenosine promotes sleepiness, thus when its activity is inhibited, our level of wakefulness is increased. Therefore, it’s possible to see how caffeine may help to combat sleepiness. However, because of these properties, caffeine can also have a negative impact on our sleep / wake cycle. As such, if we do use caffeine, it is important to be ‘caffeine clever.’
The first thing to note is that when we take caffeine into our body, it takes between 30 – 60 minutes for the drug to reach peak levels in our blood. Therefore, consider how frequently you’re taking caffeine in and be aware of when you’re likely to experience its maximum effect. It’s also important to note that the half-life of caffeine is approximately 5 – 7 hours (that is the time it takes for your body to eliminate half of the drug). That means if you have a caffeinated drink at 9am, by 2 -3pm half of the dose is still active in your body. Therefore, avoiding caffeinated drinks for 6 hours before bedtime is likely to have a positive impact on sleep. Be mindful that different foods and drinks contain different levels of caffeine and that ‘de-caffeinated’
does not mean ‘no caffeine’. The European Food Safety Authority (EFSA) recommends a maximum caffeine intake of 400 mg / day for adults. Try not to exceed this limit.
Alcohol is bad for sleep. It reduces the quality of our sleep and disrupts our natural circadian rhythm. Alcohol causes our sleep to become fragmented, it reduces the time we spend in Non-Rapid Eye Movement (NREM) sleep (when we restore our physical health), and it is one of the most powerful suppressors of Rapid Eye Movement (REM) sleep (when we restore our mental health).
There is increasing evidence to demonstrate that consistent and regular exercise is one of the most effective non-pharmaceutical treatments for disturbed sleep. When we are physically active, our body expends energy and we are more likely to feel tired and ready for a rest at the end of the day. As such, we are more likely to be able to establish a regular and healthy sleep / wake cycle.
Winding down and relaxing in the evening before bed is essential for good sleep. At this difficult time, it’s not unreasonable to suggest that many of us may find it a challenge to ‘switch off’ and fall to sleep; this can upset our circadian rhythm. For this reason, it’s important to try to incorporate a ‘wind down’ schedule and pre-sleep routine. During this period, try to avoid activities that stimulate our minds, or which may evoke anxiety (for example, watching disturbing news footage late in the evening). Instead, do things that helps bring a sense of calm. Some examples might include, having a relaxing bath, reading a book, deep breathing exercising, listening to relaxing music, keeping a gratitude diary (finding three good things about your day and writing them down).
If you’re interested in learning more about the importance of sleep and how to improve it, we recommend reading Matthew Walker’s book ‘Why We Sleep’. You can also check out our next sleep blog for further top tips to find out what organisations can do to promote good sleep.
- Walker, M. (2018) Why we sleep: The new science of sleep and dreams. Penguin