THE BENEFITS OF SLEEP EXPLAINED

According to world-renowned sleep expert and neuroscientist Dr Matthew Walker, sleep is our best superpower. Here's why...

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We live in a high-speed world where work and personal life are all too often a blur of activity. Many of us work or study overtime, pulling all-nighters to complete tasks, and believe we'll catch up on sleep another time. After all, 'you can sleep when you're dead', right? This is ill-advised, according to sleep expert Dr Matthew Walker, author of the international best-seller, Why We Sleep, and witty host of The Matt Walker Podcast.

It's a well-known fact that humans need sleep to function, but do we really know why it's so crucial for the body and mind? Thankfully, Dr Walker has the answers. He is a professor of neuroscience and psychology at the University of California, and serves as the director of the Centre for Human Sleep Science.

He goes as far as to say that sleep is a "superpower" that has been eroded by society over the last 60 years. "There's a silent sleep-loss epidemic, and it is all too quickly becoming one of the greatest public health challenges we face in the 21st century," he says. "The decimation of sleep throughout industrialised nations is having a catastrophic impact on our health, our wellness - even our children's education. We must reclaim our right to a full night's sleep without embarrassment or the stigma of 'laziness'. And in doing so, we will be reunited with the most powerful elixir of life."


OPTIMAL BRAIN FUNCTION
In an experiment conducted by Dr Walker, focusing on how sleep affects the brain's ability to learn and store experiences, it was found that people who don't get eight hours of sleep per night have a 40% deficit in their ability to make and retain new memories. In fact, their brain's hippocampus (the 'inbox' of the brain, dedicated to receiving and storing memory files) showed a concerning lack of healthy activity.

"Sleep deprivation shuts down that memory inbox of the brain, and any new incoming files are just being bounced," he explains. "The disruption of deep sleep is a totally under-appreciated factor that is contributing to cognitive decline." This is why sleep disorders are so closely linked to cases of Alzheimer's and dementia. We lose our ability to fulfil key roles and upskill when we are deprived of good sleep.

"What we've discovered over the past 10 years is that you need sleep after learning new things, to essentially hit the 'save' button on those new memories so that you don't forget," Dr Walker emphasises. "But recently we've discovered that you also need sleep before learning, too, to prepare your brain - almost like a dry sponge ready to soak up new information. And without sleep, the memory circuits of the brain essentially become water-logged and you can't absorb the new memories."

PHYSICAL HEALTH
Lack of sleep will wreak havoc on your body and immune system, making you less able to excel and live life to the fullest. It has a particularly significant impact on your cardiovascular system.

In a global scientific study involving 1.6 billion people across 70 countries that use daylight saving (twice a year), an alarming trend was observed. "In the spring, when we lose one hour of sleep, we see a subsequent 24% increase in heart attacks the following day," Walker explains. "In the autumn, when we gain an hour of sleep, we see a 21% reduction in documented heart attacks. We observe the same profile for car crashes, road accidents, and even suicide rates."

Your immune system is also negatively affected by sleep loss. Natural killer (NK) cells are required to identify invaders and eliminate them - but even just a single night of bad sleep can reduce NK cells' activity by up to 70%, leaving you at a higher risk for all kinds of illness.

"We're now finding significant links between short sleep duration and numerous forms of cancer," Dr Walker adds. "In fact, the link is so strong that the World Health Organisation has now classified any form of night-time shift work as a probable carcinogen because of the disruption to your sleep-wake rhythms."

Shorter sleep can increase the activity of genes that promote the formation of cancerous tumours, as well as those associated with long-term inflammation, stress and cardiovascular disease. Sleep deprivation has also been found to affect reproductive organs and overall sexual health, says Dr Walker. "Men who sleep five hours a night have significantly smaller testicles than those who sleep seven hours or more," he explains, adding that men who routinely sleep four to five hours a night have the testosterone level of someone 10 years their senior.

"There's simply no aspect of your wellness that can retreat at the sign of sleep deprivation and get away unscathed," Dr Walker states. "Sleep loss will leak down into every nook and cranny of your physiology – even tampering with the very DNA nucleic alphabet that spells out your daily health narrative."

In conclusion, Dr Walker cautions: "Sleep, unfortunately, is not an optional lifestyle luxury. Sleep is a non-negotiable biological necessity. It is your life-support system, and it is Mother Nature's best effort yet at immortality."

DR WALKER'S TIPS FOR BETTER SLEEP

• Stay regular: Go to bed at the same time and wake up at the same time - regardless of whether it's a weekday, weekend or holiday. This will anchor your sleep and improve both the quantity and quality of your nightly shut-eye.

• Keep it cool: Your body needs to drop its core temperature by at least 1-2°C to initiate sleep - and then stay asleep. That's why you'll always find it easier to fall asleep in a room that's too cold than you would in a room that's too hot. An ambient temperature of around 18°C is best for an optimal night's rest.

• Pay attention to your diet: Don't go to bed feeling too full or hungry. This type o discomfort will keep you up at night.

• Manage your stress: If you're worried about something, jot down your concerns before bedtime, set the note aside and then commit to dealing with it the next day. Manage your stress by staying organised and setting daily priorities per day, and try meditation to ease your worries.

• Don't use sleeping pills: Unfortunately, these are 'blunt instruments' that don't produce healthy, naturalistic sleep.

By: Charndré Emma Kippie
Photographs: Shutterstock