How Sleep Deprivation Affects Our Health

Anyone who has woken up without a proper night’s sleep can attest to the noticeable differences in the way one thinks, feels, and functions. However, what happens to us when we don’t get enough sleep, and its true significance on our overall health and functioning, is much more than one would think. Here’s what the evidence says about how sleep deprivation affects our health:

 Sleep and Our Body

Before the invention of the light bulb, people slept an average of ten hours a night. Today, many get a mere five hours of sleep [1, 2]. The relative novelty of this change in routine has several implications, affecting your body inside-out. The biggest one: it’s probably not how our body was designed to function.

Although scientists are still studying these concepts, increasing evidence shows that our sleep can make all the difference to our overall health. It allows our body to physically recover from its activity, process events and our emotions about them, and generally helps our mental and physical performance - for not only the following day, but also over time [3].

In fact – and here’s something that sleep-lovers will truly appreciate – sleeping has been shown to be one of the most important activities of the 24-hour day, when it comes to modulating our body’s functions [4, 5]. This also explains why we burn so many calories when we sleep [6]. Even the advice to “sleep over it” gets a scientific nod. Our moods and cognition are clarified and organised when we sleep [7, 8]. This is also a particularly important aspect of our personal safety; driving after a night of insufficient sleep is tantamount to driving after an alcoholic drink [9].

So, why does sleep affect us in such fundamental ways? The answer lies in the processes that take place during our sleep cycle.

Our sleep cycle has two main states [10]:

(i) Rapid Eye Movement (REM) sleep, a state of consciousness during which our muscles relax, but our brain is still active – this is where dreams occur.

(ii) Non-rapid Eye Movement (NREM) sleep - here’s when our body repairs itself, regrows tissues, builds bone and muscle, regulates hormones, and strengthens the immune system.

These two states typically alternate through the night for 60–90 minutes each; in effect, seven to eight hours of sleep would include four to five sleep cycles [11, 12].

Sleeping less than six hours a night, or poor sleep quality in general, leads to ‘sleep debt’ – where one carries around a heavy load of sleepiness day after day, with or without sleep disorders like insomnia and sleep apnea [13].

Sleep Debt and Our Hormones

Our sleep regulates at least ten different hormones that we are aware of [14]. In fact, the 24-hour sleep/wake cycle, known as the ‘circadian cycle’, controls 10-15% of our genes [15].

It’s unsurprising, then, that sleep disorders have been linked to hormonal problems [16]. Amongst these, Polycystic Ovary Syndrome (PCOS) is a particularly common hormonal condition that occurs in women, and goes on to cause skin problems, weight gain and in some severe cases, infertility [17, 18]. Sleep disorders can increase the risk of developing depression, by disrupting a mood-regulating hormone called ‘serotonin’ [19, 20].

Sleep debt, in itself, has been associated with a number of health problems. It can cause obesity, by potentially altering the key appetite hormones (e.g. leptin and ghrelin) in a manner that enhances the sensation of hunger- something that’s more pronounced in children [21]. The growth and development of children may also get disrupted, since sleep patterns affect the release of growth hormones [22].

It can even be related to glucose metabolism, insulin resistance, inflammation [23] and, most perniciously, belly fat [24]. That’s the fat that accumulates around our organs, causing all sorts of problems, and leads to lifestyle diseases like immunity problems, diabetes, heart disease, and cancer [25, 26, 27].

People who exercise regularly and don’t get enough sleep are also affected by sleep debt. It is believed to decrease protein-building and possibly increase protein breakdown, which counter-productively favours the loss of muscle mass and hinders muscle recovery [28].

While the cause-and-effect of these associations still needs to be studied further, it’s clear enough that sleep debt can be disruptive to one’s lifestyle and health goals, to say the least. It is of utmost importance that we ensure our sleep patterns are healthy and consistent.

Here’s what we can do:

1. Relax before bedtime

Any sort of cognitive stimulation (even things like watching a movie or your favourite TV show) keeps the brain active, which is the exact opposite of what it should be [29, 30].

Fretting, which can stimulate the stress hormone, cortisol, will also keep a person up [31, 32].

It’s important for us to identify ways to relax and use the most effective technique before bedtime – whether it’s a warm bath, soft music, easy stretches, deep breathing or relaxing sounds. Anything that gives the brain a break [33, 34, 35, 36, 37, 38].

2. Keep the lights turned off

A hormone called melatonin induces sleep by making us drowsy. This hormone is suppressed by light, which then disrupts the sleep cycle. This is also a reason to sleep at night (as opposed to during the day) for better sleep quality [39, 40].

3. Get the Right Nutrition

There are a lot of variations and contradictions when it comes to correlating good sleep and the amount of macronutrients [41, 42]. Having said that, there are some specific links between sleep and micronutrients (vitamins, minerals and phytonutrients) that we need to be aware of [43, 44, 45]:

• Vitamin B deficiencies, especially vitamins B12 and B6, have been linked with sleep problems.
• Vitamin D3 improves sleep quality by affecting the part of the brain responsible for sleep.
• Experts consider there to be a relationship between sleep and our magnesium and calcium levels.
• Taurine, a type of amino acid, is supposed to have a relaxing effect on the body [46].
• L-theanine improves sleep quality [47]. The catch with this nutrient is that it’s found in tea, which has caffeine. So try consuming it through decaffeinated green teas, especially ones that contain camomile and ginseng [48].

According to studies, a balanced and varied diet that is rich in fresh fruits, vegetables, whole grains, and low-fat protein sources (all of which contain plenty of tryptophan, a precursor to melatonin, have been shown to promote sleepiness) as well as group B vitamins, minerals, and unrefined carbohydrates can improve sleep [49].

All the things above would prove helpful only when you favour and prioritise your sleep time for real.

Humans are creatures of habit, which makes it important to gradually set up a routine where we get at least six hours of sleep daily. Let these evidence-based facts remind us why it’s needed. We wish you a good night’s sleep, today and every day. :)