A new book by Sleep Scientist, Matthew Walker, reveals the dark truth behind sleep deprivation's impact on a person's health and well-being.

Walker, who is also director of the Centre for Human Sleep Science at the University of California, highlights the damaging effects of sleep deprivation and its link with Alzheimer's, cancer, diabetes, obesity and poor mental health.

In a recent interview with the Guardian, Walker discusses why lack-of-sleep is a modern condition, and what happens to your body when it's deprived of sleep.


What is sleep deprivation?

Put simply, sleep deprivation is a condition where you're not getting enough sleep.

What is a normal amount of sleep?  Well, that's quite subjective, but the NHS broadly define a 'normal' amount of sleep as between 7-9 hours per-night.

The short-term side-effects  of sleep deprivation include: prolonged daytime tiredness, mood-swings, hunger and clumsiness.

If you're suffering from insomnia or prolonged sleep deprivation, and it's affecting your daily life, the NHS recommend you make an appointment with your GP.

There are some environmental and lifestyle changes you can make to improve the quality and length of your sleep which we'll explore in greater detail further on.


How does sleep deprivation impact your health?

The link between shorter sleep and a shorter lifespan  has been chronicled across 20 epidemiological studies.

One study revealed that adults over 45 years who sleep less than 6hrs a night are 200% more likely  to have a heart attack or stroke than someone who's sleeping 7/8hrs a night.

This is linked to blood pressure, where just 1 night of poor sleep increases the rate of a person's blood pressure.

Poor sleep has long-been linked to obesity,and Walker goes into further detail on this.

When we're not getting enough sleep we're more susceptible to weight gain. This is because we start to experience decreasing levels of leptin, which inhibits hunger, and increasing levels of ghrelin, which increases hunger.

We also start to lose control of our blood sugar levels and become less responsive to insulin, leading to a pre-diabetic state of hyperglycaemia - a sign of diabetes.

Sleep deprivation - or insomnia - also has a detrimental effect on our immune system.

If you're exhausted, your immune system is weakened and less resilient to common colds, viruses and the flu.

Studies have also shown that sleep deprivation has a negative effect on cancer-fighting immune cells, increasing the odds of developing breast, prostate, endometrium and colon cancer.


The link between sleep and mental health


When you're in a deep sleep, you're actually in a state of therapeutic bliss, suggests Walker.

This is echoed in a study Walker conducted where brain scans revealed sleep deprived children experienced a 60% increase in reactivity of the amygdala  - the area of the brain responsible for emotions such as anger and rage.

Sleeplessness in children has thus been linked to heightened levels of aggression. Disturbingly, sleep deprivation has also been linked to suicidal thoughts in teenager.


Why are we sleeping less?


Blue Light - Sleep Deprivation


In 1942, 8% of the population survived off less than 6 hours a sleep per-night. In 2017, that figure has ballooned to an incredible 50%.

But why are we sleeping less?

Walker considers multiple factors behind this phenomena, notably:

  • Using electrical devices at night.
    LED-emitting devices are known to impact melatonin, which is the hormone responsible for sleep.
  • Work-life balance. 
    As we work longer hours, our sleep begins to suffer. In order to accommodate extra hours at the office, we're sleeping less to try and squeeze in time with the family and other social activities.
  • Alcohol and caffeine. 
    Both have detrimental effects on sleep quality and patterns. When we consume more of both, our sleeping habits are impacted.
  • Our perspective of sleep. 
    Walker argues, as a society, we view sleep as a weakness: that admission of tiredness is something to be ashamed of, and in turn we try to get through the day on just a few hours of sleep fuel.
  • Poor sleeping environments. 
    The NHS suggest a poor sleeping environment, such as an uncomfortable bed or mattress, or a bedroom that's too light, noisy, hot or cold, can prohibit quality sleep.
  • Physical and mental health. 
    According to the NHS, longer-term health conditions such as heart problems and depression can negatively impact sleep duration and quality.


How do I get better sleep?


Dr Nerina - Sleep Deprivation


It's time we prioritised sleep.

Walker makes sure he allows for 8 hours of sleep every night - a non-negotiable agreement he's made with himself. He also keeps regular sleep hours to establish a consistent sleeping routine.

Walker also recommends that we avoid pulling 'all-nighters' of any variety, whether that be squeezing in a few more pints at the pub, or staying in the office until late.

In fact, after just 19 sleepless hours, you're as cognitively impaired as someone who's drunk  - this has obvious consequences on your ability to perform tasks such as driving or operating machinery.

Walker, however, warns against the use of sleeping pills, which can have a damaging effect on memory.

There are also questions around the effectiveness of over-the-counter sleeping pills for treating insomnia, as well as concerns over how they can make individuals feel drowsy and impaired the next day.


Silentnight's very own sleep expert, Dr Nerina, has a host of tips for getting better sleep here, including:


    • Moderating alcohol and caffeine consumption
    • Keeping well-hydrated
    • Eating more foods that boost melatonin, the sleep hormone, such as; chicken, milk, dairy and seeds
    • Maintaining a tech-free sleeping environment to reduce the amount of exposure to sleep-inhibiting blue light


For more sleep tips, visit our Sleep Matters blog here.




Sleep Association, "Sleep Deprivation": https://www.sleepassociation.org/sleep/sleep-deprivation/


The Guardian, "The Shorter Your Sleep, The Shorter Your Life:
The New Sleep Science":


NHS, "Insomnia":