It used to be commonplace, especially in the work environment, that people prided themselves on how little sleep they need to function. I remember clearly, a senior manager at our strategy consultancy firm, would boast to the team about how he only needed four or five hours maximum. "Sleep when you’re dead” was the motto, and in the meantime just work all other hours, was the implicit message role modelled.
Thankfully, society is gradually moving away from that now-dated thinking, with increasing awareness on the need to prioritise physical and mental wellbeing and the strive to achieve more work-life balance.
For many of us, sleep is what we do when we have exhausted all other options. It is the left-over time after a full day of work, family responsibilities, household chores, socialising, leisure time, and so on. Little do we know that sleep is a major cornerstone of health, on level, if not a pre-requisite to nutrition and exercise.
Two Opposing Mechanisms
While we have gotten collectively better at putting more boundaries around work, there are still two opposing mechanisms that continue to chip away at our sleep time:
1. The push to be more productive: To get the most of every single day, we find ourselves moving from one task to the other. This is noticeably more pronounced for working parents, whose evenings are taken up by admin tasks, work e-mails, and household chores. Slowly, we are shifting towards becoming "human-doings", no longer "human-beings".
2. The pull to switch off: Having been overloaded with work and family stressors throughout the day, many people, especially working parents, seek a complete and well deserved shut-down in the evenings. So, we head to our television sets and mobile devices for some mind-numbing content. I’m all for it, by the way, and I do it myself. However, I am lately much more aware and actively managing the time spent on screens, in lieu of precious sleep. When switching off while awake starts to take away from the much-needed full switch off when asleep, the health issues start to emerge.
The Multi-faceted Functions of Sleep
Let’s clarify the basics before we dive in. Sleep is controlled by two distinct processes: Circadian Rhythm and Sleep Pressure.
Circadian rhythm is our built-in body clock, controlling most of our bodily processes. It is influenced by light exposure, and it is key to signalling sleep. At night, cortisol levels decrease, and melatonin levels increase to induce sleepiness; these two hormones work in opposition. This is why when we are stressed and cortisol is high, we find it harder to sleep!
Sleep pressure is caused by the build up of the neurotransmitter adenosine which starts accumulating when we wake up and gets cleared during sleep. Caffeine works to block our adenosine receptors, however once the effect of caffeine fades, the tiredness also returns, causing a caffeine crash, and keeping us hooked on the stuff throughout the day.
Furthermore, sleep is characterised by two main types of phases, NREM (non-REM) and REM.
We need both, for different reasons!
NREM sleep usually happens mostly in the earlier stages of sleep, and account for roughly 75% of our sleep time. NREM is responsible for restoring the body and its key processes. During this period, tissues are repaired and renewed, memories are de-duplicated and consolidated, and our immune cells go around combating unwanted invaders.
REM sleep is better known as our dream phase. It usually takes place in the later stages of sleep closer to dawn, and accounts for 25% of our sleep time roughly. In this phase, we experience high brain activity levels, the creation and strengthening of new neural connections, and the ability to connect the dots and come up with creative solutions for issues we have been grappling with.
Therefore, when we stay up late in the evening, we are chipping away at our body’s ability to heal and regenerate physically, and when we cut short our sleep in the morning (think the 5am club), we are cutting short our ability to remember, think, and be creative. If we’re doing both, then the damage is multiplied!
Sleep Loss and Links to Chronic Disease
Sleep loss, described as less than 7 hours in bed, has been scientifically linked to an increased risk of the top four chronic diseases, which are responsible for most causes of human mortality: Heart disease, Metabolic Disease, Cancer, and Alzheimer’s Disease. In the next paragraphs, I draw on the work of Dr. Matthew Walker on the topic of sleep and chronic disease, as publicised in the book, Why We Sleep.
Sleep and Heart Disease: Sleep loss is associated with 45% increased risk of developing or dying from heart disease. If the sleep time is consistently less than 6 hours across many years, as a Japanese study of 4,000 males showed, then the cardiac arrest risk becomes 400%. This is especially relevant in mid-life, when our body begins to deteriorate, and with it the quality of our sleep. The reason triggering this increased cardiovascular risk has to do increased heart rate and elevated blood pressure, resulting from sub-optimal sleep. This ultimately narrows the arteries, starve blood oxygen, and increases the risk of heart attacks and strokes.
Sleep and Metabolic Disease: Weight gain, Insulin Resistance and Type 2 Diabetes. When you are lacking in sleep, the hormones leptin (triggers satiety) and ghrelin (triggers hunger), stop functioning properly. Leptin becomes underactive and ghrelin overactive, leading to endless cravings throughout the day. Sleep-deprived people will tend to consume more calories in the day, and especially choose junk foods, which will seemingly appease the craving better. In sum, getting enough sleep will help you better manage your weight. More alarmingly, lack of sleep also hijacks the body’s effective control of blood sugar levels, which lays the foundations for reduced insulin sensitivity, and increases risk of developing Type 2 Diabetes.
Sleep and Cancer: After several nights of sub-optimal sleeping, the body is rendered immunologically weaker. According to a studying conducted by Dr. Irwin at UCLA, a single night of 4 hours sleep can sweep away up to 70% of the natural killer cells in your body, which are responsible to eliminate threats like viruses. bacteria, and rogue cells (i.e. cancerous cells). Indeed, poor quality and quantity of sleep not only increases the risk of cancer development, but makes the growth more rapid, if the cancer is already established.
Sleep and Alzheimer’s Disease: “Sleep disruption and Alzheimer’s Disease interact in a self-fulfilling negative spiral that can initiate or accelerate the condition.” Alzheimer’s disease is associated with the build up of plaques from the protein beta-amyloid, which is poisonous to our brain cells. Deep sleep in the NREM stages is when the brain is effectively cleaned of this amyloid protein debris, so once that phase of sleep is compromised, the grounds for neurological diseases become riper. Sleep alone will not be the silver bullet that eradicates dementia but it sure is a priority for lowering the disease risk.
Sleep Enhancing Tips for Chronic Disease Prevention
Now that you better understand the gravity of the impact of sleep loss, let’s explore the tangible steps you can take to optimise your sleep duration and quality.
Aim for a minimum of 7 to 9 hours in bed: Set a bedtime reminder on your phone, like how you set an alarm to wake-up.
Keep a consistent bedtime schedule: Try to sleep around the same time every night. Of course, there will be exceptions! It’s not about perfection.
Set your circadian rhythm by making sure you get direct natural sunlight in the mornings, so that come evening time, you feel the need to sleep.
Be intentional about how you spend your evenings: Instead of automatically planting yourself on the sofa in front of a screen, explore other interesting alternatives like reading, calling a friend, or chatting to your significant other (without looking at phones!)
Avoid using screens in bed: Blue light induces wakefulness, and looking at your phone increases the likelihood of mindless scrolling.
Turn down the lights in the evening: This gives a signal to your body to start producing the sleep-inducing hormone melatonin.
Keep a cool bedroom temperature.
Monitor your caffeine consumption: Avoid caffeinated drinks after midday.
Manage your alcohol intake: Consider swapping your nightly glass of wine with a nightly herbal tea.
Have an earlier dinner: Try to keep at least 3 hours between your last meal and your bedtime.
In conclusion, sleep is one of the most fascinating topics that researchers are still working on fully unpacking. Science has made huge leaps in this understanding thanks, almost single-handedly, to the work of Dr. Matthew Walker, which is beautifully detailed in his book “Why We Sleep”. I recommend everyone to read it.
If you’re keen to explore ways to optimise your sleep as part of a more holistic chronic disease prevention effort, why not consider working with a health coach, who can help you identify your health goals, and make tangible changes in how you feel in yourself. As a Health Coach, I have supported many clients, in adopting healthier sleep habits, despite the demands from work and a young family.
Start by scheduling a complimentary 30 mins health review, with Nada Soubra (Resilience & Metabolic Health Coach), which you can book directly in the calendar here: https://calendly.com/thehealthychain/free-coaching-trial-session
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