Seven Reasons Sleep is Even More Important than I Thought

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I’ve just been doing an online course in sleeping. I’m not even kidding. It’s called The Science of Better Sleep and is available through Masterclass. It seemed a little frivolous as a topic – especially as I feel I already know why sleep is important – but it was full of surprises. Not all of them pleasant.

It turns out that sleep is arguably as important to our health as eating well and exercising. Sleeping well can guard against a range of diseases, from diabetes to Alzheimer’s. It can help us lose weight, and gain muscle, learn better, and avoid (sometimes fatal) mistakes.

As Matthew Walker (who teaches The Science of Better Sleep) puts it:

“Scientists have discovered a revolutionary new treatment that makes you live longer. It enhances your memory and makes you more creative. It makes you look more attractive. It keeps you slim and lowers food cravings. It protects you from cancer and dementia. It wards off colds and the flu.”

Sleep is vital. I will never feel guilty about sleeping in again. It’s not lazy, it’s healthy. Here’s why.

Sleep helps you lose weight

New research suggests that just one extra hour of sleep every night could help sleep-deprived people who are overweight eat 270 fewer calories per day, without even trying.

What’s more, sleep actually helps you build lean muscle, which may seem counter-intuitive, but actually makes sense if you think about it

. Your muscles ‘tear’ while you’re working out but repair and grow while you’re sleeping.

Sleep alone won’t build muscle, sadly, but if two people do identical workouts and one sleeps a lot longer than the other, their muscles will have more chance to grow.

Given how many illnesses and chronic conditions are linked to being overweight, sleep is literally about life and death. In fact according to sleep specialist, Walker, there is a 200% increase in the likelihood of heart attack or stroke among adults of 45 or older who routinely sleep fewer than six hours a night.

Sleep is already looking more important than it previously did, isn’t it?

Sleep may protect against Alzheimer’s disease

It’s common for people with Alzheimer’s and other forms of dementia to sleep badly, and this is often thought to be a symptom of the disease. Walker suggests, however, that given how important sleep is for brain health, it may actually be the case that poor sleep habits are a risk factor for dementia, rather than simply a result of it.

While more research is needed, there is increasing evidence that lack of sleep in middle age may actually increase dementia risk as we age. Cutting down on sleep in order to work and earn more money may seem like a good idea on the surface, but have you seen the cost of specialist dementia care? It might be a better idea to just get the sleep in while you can.

Sleep helps you learn better and improves memory

Learning and memory function is highly linked to sleep. You need sleep before learning to prepare the brain for absorbing new information. You also need sleep after learning to cement that information and enable your brain to make the connections and associations needed to really embed that new information as long-term knowledge.

Walker conducted a study where healthy young adults were either allowed a normal 8 hours of sleep, or completely deprived of sleep for the night. The individuals were then placed in an MRI scanner and asked to try and learn a list of new facts, while the researchers essentially took snapshots of their brain activity.

The subjects were then tested on that new knowledge, only to find that there was an almost 40% deficit in the brain’s ability to make new memories under conditions of sleep deprivation. If you’ve ever pulled an all-nighter the night before an exam, it’s likely you would have been much better off studying for a couple of hours, getting several hours of sleep and then studying for another hour.

Sleep prevents minor illnesses too

People say there’s no cure for the common cold, and they’re right, but there is a preventative strategy and it’s simply getting a good night’s sleep. One study found that people who sleep six hours a night or less are four times more likely to catch a cold when exposed to the virus, compared to those who routinely sleep more than seven hours a night.

Sleep improves immunity and antibody response

There is also evidence that sleep strengthens immune memory, boosting our natural immunity and even improving antibody response after vaccination. Multiple studies have confirmed that sleep duration at the time of vaccination against viral infections can affect immune response.

One study indicated that ten days after vaccination against seasonal influenza, antibody response in individuals who were immunised after four consecutive nights of sleep deprivation was less than half of those measured in individuals without a sleep deficit.

The daylight savings effect

Perhaps most worrying is the instant and potentially fatal impact of losing just one hour of sleep. An issue that was brought to light by research indicating that when the clocks go back for daylight saving each year, it causes an spike in car accidents, including a 6% increase in fatal car crashes, in the following week. Daylight savings is also correlated with an increase in workplace injuries, stroke and heart attack.

Some mistakes are fatal on a bigger scale

In her book, Thrive, Arianna Huffington invites us to consider what the explosion of the Challenger space shuttle, Chernobyl’s nuclear disaster, and the Exxon Valdez wreck have in common. 

The immediate thought might be they were all large scale disasters. Huffington points out that they were also all at least partially caused by human error that was ultimately linked to sleep deprivation. Lack of sleep can kill us, and those around us too, occasionally.


Not getting enough sleep? There’s no easy fix (sorry about that). But at the very least:

  • Make your bed as comfortable as possible. A high-quality memory foam mattress works for some people, but mattresses are personal. Buy the one you know you’ll sleep best on.
  • The right pillow is also way more important than most people realise. Try this scrumptious one from Honeydew. But again, this is personal. Get the pillow that works best for you
  • Keep things cool. Experts suggest somewhere around 65F (just over 18C) for optimal sleep.
  • Cut out caffeine in the evenings (personally I cut it out from midday onwards – and only hit the Sleepy Time tea for a bedtime drink).
  • Devise a bedtime routine that truly relaxes you. For me it’s yin yoga, warm bath, read (a real book – no blue light), and maybe sex (the relaxing kind).
  • Compromise with your partner (not about the sex, though maybe that too). It’s important that you both get a good night’s sleep in spite of differences in routine, preferred temperatures etc. Some couples swear by this Scandinavian sleep method.

The simple fact is that sleep is necessary to our health. There’s no need to feel lazy or guilty for getting plenty of sleep. In fact, it’s feasible to suggest that sleeping in is just as good for our health as getting up early to exercise, meditate, or eat a healthy breakfast.

Honeydew scrumptious pillow

Originally published on Medium. Re-posted here with permission.

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