In this week’s article, we look at the relationship between sleep and health. We also give you the top tips on how to improve your sleep.
We all know sleep is a vital part of our day. When you sleep, your body does a multitude of jobs including muscular repair, memory processing as well as regulating hormone patterns. Sleep, however, is usually one of the first areas in our lifestyle that we tend to sacrifice for other lifestyle factors:
You may get reduced sleep due to the demands of work commitments. Early starts and late finishes leave you operating on short sleep time.
You may have a new-born which dictates your sleep. Babies have a different sleep pattern mixed between sleeping and feeding, especially in the early development stages. Maybe your significant other works a separate schedule to you, and you wait for them to return home before going to bed?
You might be someone who goes to bed late out of habit. Maybe you need to ‘unwind’ after a hard day and fulfil your hobbies or catch up with loved ones. You might be engrossed in a series of programmes that leave you suffering ‘just one more episode’ syndrome.
You may have had a recent change in daily life that affects your sleep. You may have recently changed jobs, which means your schedule may have shifted. Maybe you have taken on additional tasks that require your time away from regular scheduling? Your body clock, or circadian rhythm as its technically called, dictates the cycles of alertness and tiredness you experience during a 24 hour period. The circadian rhythm will be set to your most current pattern and can take some time to shift to a new one.
You may suffer from one of the multiple sleep disorders that affect your ability to get good sleep quality, quantity or both. Some sleep disorders may be due to lifestyle, but others may be due to illness or a side effect caused by another condition or medication.
How much sleep?
Out of all the situations mentioned above, sleep is usually the easiest to change to suit your circumstances. You may de-prioritise the amount of sleep you have so you can fit other activities into your day. But what effect is this having on your health? Before we can answer this, there is one question we need to answer: how much sleep should you be having?
Your age dictates the amount of sleep you should have. As life progresses, the suggested requirement of sleep changes. Below are the medical recommendations for sleep duration, based on age:
New-borns – require between 14-17 hours within 24 hours.
12 months – average 10 hours at night then 4 hours total of naps
Two years – 11 to 12 hours at night plus 2 hours total of naps
3 to 5 years – 10 to 13 hours at night
6 to 13 years – 9 to 11 hours at night
14 to 17 years – 8 to 10 hours at night
Adults – 7 to 9 hours at night
So, as adults, we should be aiming for an average of 8 hours per night. For example, you should be able to sleep between 11 pm, and 7 am each day to tick the requirement box. Some individual factors affect this. You may naturally wake up feeling refreshed after only a few hours. On the other hand, you may feel having 8 hours a night isn’t enough and if you were left uninterrupted, you could sleep 10+ hours naturally.
Stages of sleep
When you sleep, rather than just being awake or asleep, your body goes through different stages or depths. There are two categories of sleep: REM (rapid eye movement) and Non-REM (NREM). During sleep, we cycle through these two types of sleep in a form of wave cycle. Starting in NREM and then into REM, back out into NREM and the cycle begins again. Each cycle is roughly happening every 90 minutes, provided that your sleep is uninterrupted.
NREM stands for non-rapid eye movement. It is what we experience when we begin the fall asleep through to the middle of each cycle. NREM happens in several stages:
N1: This is the lightest form of sleep, which is the transition between being awake and being asleep.
N2: This is the actual onset of sleep. During this phase, although breathing and heart rate remain unchanged, your core temperature begins to drop.
N3: The deepest stage of sleep and the most restorative to your health. During this stage, a series of activities happen within the body. Your breathing will begin to slow down, and your heart rate will drop. The endocrine system, which is in control of hormone release, becomes most active, releasing pulses of growth hormone. Growth hormone is responsible for the recovery, growth and development of multiple different tissues in the body. It is also responsible for modulating metabolism and assists in fat burning!
While we are talking about hormones, it’s essential to mention cortisol. Cortisol is a stress hormone that we covered in our previous article on how to manage stress. Cortisol will drop as we begin to sleep, but will also start to increase during the night to help us to wake up and be ready to go.
No, not the famous rock band from the 80s: REM stands for rapid eye movement. REM is the midpoint of the sleep cycle which links the N stages to create the wave pattern. The first REM cycle starts after being asleep roughly 90 minutes and lasts for 10 minutes. With each cycle, the length increases up to one hour. During this stage, your body relaxes, and muscles begin to turn off. Energy is provided to your brain as your eyes start to dart back and forth, hence the name. As the brain is most active, it’s this stage where we begin to dream.
If you manage to get 8 hours of good quality, uninterrupted sleep, you will go through 5 sleep cycles. The first two cycles will see the deepest and longest dips into the N3 stage, with the following cycles reducing their depth and length. As the N3 stage decreases with each cycle, the REM stage increases. We need the five cycles of sleep each night to allow for all the health and restorative benefits, which is why 8 hours is the average requirement. As a side note, the ‘ideal’ lifestyle balance should be 8 hours of work, 8 hours of leisure and 8 hours of sleep, although given modern lifestyles, this is less likely to be achievable.
But what about naps?
You may have heard or even followed the idea that “if I can’t get enough sleep at night, I’ll make up the difference in naps”. On your days off, you might try to play ‘catch up’ by having an additional nap during the day. Taking the odd nap might help restore some of your alertness and energy, but taking naps does not help count towards your daily total. As we have explained above, we require an average of 90 minutes per cycle of sleep. The duration of napping means you don’t tick the boxes for good quality, restorative sleep. Be warned; although a short nap can help to restore your energy, you run the risk of slipping into a deeper stage of the sleep cycle. When you wake up during a deeper stage, it can leave you feeling more tired and groggy, so try to keep naps to 45 minutes.
The sleep – health continuum
Sleep and health go round in a cycle. Poor health negatively affects your sleep quality and quantity. On the other hand, poor sleep quality and quantity can adversely affect your health. Unchecked, this can create a cycle of decline or limit your ability to improve your health. Several lifestyle habits can contribute to poor sleep, which we will cover later in this article. You might also suffer from sleep disorders that affect your sleep. The three most common sleep disorders are insomnia, narcolepsy, and sleep apnoea .
Insomnia is a condition that can stop you from getting to sleep or cause short, infrequent sleep patterns. Several factors can cause insomnia: these include additional stress, change in routine or an uncomfortable temperature. There are a few habitual changes you can make to help assist in improving sleep which we will discuss at the end of the article.
Narcolepsy is the opposite of insomnia. If you suffer from narcolepsy, your body cannot regulate its sleep-wake cycles. You will be prone to feeling tired and exhausted at random times throughout the day. It is not uncommon for sufferers of narcolepsy to fall asleep involuntarily. Although narcolepsy tends to be hereditary, scientists are unsure what triggers an individual to suffer from it. There are no current cures available. However, there are specific lifestyle changes you can make to help alleviate it. If you feel that you suffer from narcolepsy, please consult your G.P.
We are going to look at sleep apnoea a little closer because it’s a disorder that can have a more significant link to your current health, weight and lifestyle. There are three types of sleep apnoea: Central sleep apnoea (CSA) is a condition where your brain forgets to send the signals to the muscles in the body to take a breath. CSA is found more in developing infants or in adults as a side effect of other medical problems. Obstructive sleep apnoea (OSA) is where the airway gets closed or blocked temporarily, preventing you being able to draw a breath. OSA is a more common form of sleep apnoea and one that’s linked to weight gain and lifestyle habits. The third form of sleep apnoea is when there is a mixture of both CSA and OSA.
OSA affects 1 in 5 adults on a mild level, and 1 in 15 on a severe level. As the airways become blocked it can cause difficulties breathing and excessive snoring. OSA is the closing of the air passageways as you sleep. As we gain additional weight on our bodies, we accumulate body fat in the neck area. This extra weight can cause increased blockage and the risk of developing sleep apnoea. Due to this, weight loss is usually the first course of action suggested by medical professionals for the treatment of OSA.
Conversely, suffering from apnoea can make you gain excess weight. Poor sleep quality interferes with the endocrine system, as mentioned earlier. By negatively interfering with the endocrine system, you create incorrect hormone patterns which interfere with appetite and energy levels, leading you to eat more and move less. A negative feedback loop is created: sleep badly -> gain weight; gain weight -> sleep badly. This makes it difficult for those suffering from sleep apnoea to alleviate it. It will take some additional will power, motivation and support to take those all-important first steps to eat less and move more so you can sleep better.
If you are overweight, focusing on reducing your weight through diet and exercise, as well as improving your daily habits, will improve your sleep quality. Making these changes will contribute to the knock-on health benefits of losing weight. The improvement in sleep quality will also help you keep the weight off as your body will be releasing the right hormones at the correct times. As much as sleep and weight share a negative feedback loop, they also have a positive one.
How health and sleep interact
Below we will look at how sleep is involved in some of the essential processes your body conducts to keep us healthy, and we highlight how sleep can have an effect on those systems.
Sleep and the endocrine system
We have already discussed how the endocrine system and sleep are linked. When you sleep, the body releases growth hormone and limits the secretion of thyroid-stimulating hormones and cortisol. The endocrine system works on your circadian cycle, which dictates which hormones are released and when. Alongside the hormones already mentioned, melatonin is released, which signals your body to prepare for sleep.
Suffering from sleep deprivation or disorders, such as sleep apnoea, can interfere with the release and suppression of hormones, which can have a knock-on effect throughout the body as these hormones usually signal other actions to happen within the body.
Sleep and the respiratory system
Both ventilation and respiration are affected when we sleep. Ventilation is the amount of air travelling in and out of the body. Respiration looks at the transfer of oxygen in and carbon dioxide out of the lungs. When you sleep, your breathing will speed up and slow down dependant on the stage of the sleep cycle. As we have mentioned, sleep apnoea will affect your ability to breathe. Regular interruption to the respiratory system can lead to increased risk of hypertension, coronary heart diseases and increased blood sugars.
Sleep and the cardiovascular system
Much like the respiratory system, the cardiovascular system will change during sleep. It is common in the later stages of sleep, closer to wake-up time, that your heart rate and blood pressure rise. During this period you are more likely to suffer from a heart attack at rest. Arrhythmias are common during the night due to the change in rate and rhythm of the heartbeat. Arrhythmias increase in people suffering from sleep disorders, which increases the risk of strokes and heart attacks. One study showed that getting five or less hours of sleep per night created a 45% increased risk of heart attacks.
Sleep and the musculoskeletal system
When you sleep, the body reduces activation of the skeletal muscles to reduce the risk of injury from moving around without conscious control. If you suffer from a disorder that affects the joints, bones or muscles, such as arthritis or fibromyalgia, it can lead to low-level pain, which can stop you progressing in the sleep cycle. If this happens, it can lead to an increase in fatigue and a decrease in quality of life.
Sleep and the immune system
Lack of sleep can trigger acute stress symptoms. We have discussed this previously in the stress blog and how stress affects the immune system. There is also a link between NREM and immune function health that shows how a decrease in one can cause a reduction in the other.
How to improve your sleep quality
Sleep is not just required to restore your energy: it is a vital part of the hormone cycle which regulates and affects all other bodily systems. Just to be clear, though, if you suffer from a prior condition, you won’t necessarily improve all of the above systems. However, what we are saying is getting better quality sleep can improve overall health and alleviate any ongoing issues you may be experiencing. There are several ways you can improve your sleep, which we list below.
Exercise gives us a two-fold benefit. First, as discussed, losing weight can assist in improving sleep quality. The best way to achieve weight loss is through a combination of a calorie-controlled diet and a carefully planned exercise routine. Another benefit of exercise is that it can leave you feeling tired as your body wants to start the recovery process. Avoid working out close to bedtime as this can interfere with your endocrine system, making it harder to get to sleep.
The old myth used to be that you should not eat after 6 pm. The truth is you can eat any time of the day. As long as your body has had time to digest the food, eating late evening is fine. Some foods can help you get better sleep. For example, a small portion of oats with a teaspoon of honey and a portion of almonds will contain amino acids which help with the production of melatonin. Not only that, but it will also contain tryptophan and magnesium, which reduce nerve function and naturally steady your heart rhythm, which will aid in getting to sleep. Or maybe you could have a banana – they contain both serotonin and melatonin!
Technology and sleep
Technology has become a big part of modern-day life. We all spend a considerable amount of time either staring at our phones or tablets, working at laptops or watching TV. We could spend a whole article discussing the dangers of technology addiction, but for this article, we want to discuss blue light. Your eyes view images in light beams. These beams travel into your retina and to your brain where it converts the light to an image.
Blue light blocks your body from producing melatonin, which signals the body to be tired and prepares you for sleep. With a lack of melatonin, you will feel drowsy but find it difficult to switch off and go to sleep. Ideally, it is good practice to avoid exposure to technology for one to two hours before going to sleep. Ideally, what you should do in the evening is turn off the phone, laptop or TV and pick up a book and read before bed.
For some people, this might be too much of a challenge. In that case, you can purchase specific blue light blocking glasses and download apps on your phones which can reduce the amount of blue light you take in. Ideally, your bedroom should be a technology-free zone: no TV, no computer, no phone. Try and have your bedroom set up purely for sleeping with no option to become a ‘comfy office or lounge’.
Set a bedtime
When you were little, no doubt, your parents imposed a bedtime in which you had to be tucked up and lights out ready for sleep. As you become an adult and have more freedom, bedtime becomes less structured and more ‘I will go to bed when I’m tired’. You may find it more beneficial to re-set a bedtime structure. If you know you must get up for 6:30 am to get ready for work, you might want to consider starting your bedtime routine around 10 pm. For most, this may be a struggle and require some restructuring of your daily schedule, but if that evening time is spent sat in front of the TV, that time will be more beneficial spent getting tucked up in bed.
Controlling your room temperature is essential to help you get to sleep and keep you asleep. The ideal bedroom temperature is around 18 degrees. Depending on the time of year, you can control this with a thermostat, air con, heating or even just the layer of clothes and bedding you use.
Sleep in the dark
Make sure your bedroom is as dark as possible. Avoid using bright colours and invest in some blackout blinds where possible. The presence of light interferes with your body’s ability to produce melatonin. Being in a dark environment sends signals to our circadian rhythm that we should be getting ready for sleep, so a dark bedroom might help you get to sleep sooner.
Dear diary. . .
Sometimes, you may struggle to get to sleep if your brain is overactive. You may be thinking about things you need to remember for the following day, or tasks you need to complete. If you suffer from this, it can be a handy practise to keep a note pad by your bed where you can jot down any vital memos you need to remember. By doing this, you might find it easier to nod off, knowing you don’t need to stress and worry.
Sometimes, we don’t give our sleep the priority it deserves. Having a good sleep schedule and setting a bedtime may provide you with the nostalgia of being a child, but from a health and well-being point of view, it might be one of the better courses of action you could take. Eating healthily and exercising, combined with a better daily structure, can help you get a better night’s sleep. And let’s face it, who would not like to get better sleep, right?!