How’s your sleeping? Sleep is one of those things we often pay little attention to unless you have a sleep disorder or have difficulty getting enough. What’s the link between our brain and sleep?
We’ve heard it before – how we are all horribly sleep deprived and how this is impacting our health, mood, our memory and thinking skills. And yes, while it’s true many of us struggle to get enough shut-eye there are others who have no such issue. In fact, they’re happily tucked up under their doona for far longer, maybe nine or ten hours.
Does this matter?
Is sleeping longer as bad for us as not sleeping enough?
This is what a group of neuroscientists from the University of Western Ontario Brain and Mind Institute set out to discover. Their findings from the world’s largest brain and sleep study were recently published in Sleep. Over 10,000 people from around the world took part, completing an in-depth questionnaire and undertaking a battery of 12 cognitive tests supplied by Cambridge Brain Sciences (CBS) to examine selective attention, reasoning, verbal short-term memory, spatial working memory, planning, visuospatial working memory, cognitive flexibility and various aspects of inattention.
The questionnaire asked questions about people’s sleeping habits, what medication they were taking, their age, where they lived and what level of education they had received.
Can you guess what they discovered? Let’s take a look at the 5 big takeaways….
1. Many of us fall way below the bar of getting enough sleep
While it’s recommended we get between 7 and 8 hours of sleep for better brain health and function, around half of the respondents were getting 6.3 hours.
Worse still those who reported that they were surviving on four hours or less, performed as if they were nine years older on their cognitive tests. Eeeeek!
This is not good news if you’re a bright go-getter seeking to climb the corporate ladder and are currently burning the candle at both ends in order to achieve this.
I listened in horror to a conversation where a CEO, a woman in her mid-thirties shared how she regularly only gets 4-5 hours sleep because this is what she perceives as necessary to stay at the top of her game. She cheerfully added that while she knew this was probably not ideal in the long term, she anticipated being able to back off from her work a little in four-or-five year’s time.
Have I mentioned that the first insight we lose when chronically sleep deprived, is just how tired we are?
And that chronic sleep deprivation increases our risk of heart disease, diabetes and obesity?
Not only that it leads to detectable impairment in our overall cognition. Whether you’re running a company, leading a team or working on the tools, being able to think clearly, rationally and logically is imperative to everyone’s safety.
2. Age doesn’t come into it
Adults (over the age of 18) regardless of age all need 7-8 hours of sleep for a highly functioning brain. Neither did age have any bearing on those who were deemed to be sleeping too much or too little in terms of cognitive impairment.
3. There is an optimal amount of sleep
Yes, you guessed it, seven to eight hours of good quality uninterrupted sleep is the ideal for better reasoning, verbal and overall cognition.
4. What about the long sleepers?
The brain is often described as being a bit of a Goldilocks. Everything has to be in balance for it to function at it best and this is certainly true in relation to our sleep patterns. Sleeping for too long isn’t good for us either.
Yeah, I know, you just can’t win!
Why this should be, apart from being grossly unfair remains a bit of a mystery. However regularly sleeping in excess of eight hours has been linked to an increased risk of depression, poor health, reduced physical fitness and increased morbidity. It’s also associated with greater sleep inertia that lasts longer and is more intense. Sleep inertia is that horrible groggy feeling when we are woken from our slumbers by the alarm clock, our kids jumping onto the bed to announce it’s time to play at 3am or the dog scratching on the door asking to be let out for a wee.
Not feeling fully awake can have disastrous consequences if you’re suddenly being called upon to make that important decision or solve a problem.
“Sorry to disturb you Mr. President, we have a situation developing…”
5. There’s a world of difference between short-and-long term sleep deprivation on our cognition
Long term sleep deprivation appears to have a prolonged effect on reasoning and verbal ability but little on short-term memory performance. That’s good to know because I guess we’ve all had those nights where sleep eludes us for one reason or another. One thing this study did reveal was that having a slightly longer night’s sleep than normal when you’re normally running a bit short will boost performance the next day.
Meaning that even one good night’s sleep can make a positive difference. Thank goodness there’s a silver lining after all.
So , where do you lie on the spectrum of sleep?
Are you getting enough, verging on too much, or getting it about right?
While we are all individual, and genetic differences do play a role, it appears we all benefit from getting enough – but not too much – good quality sleep.