In the first post I focused mainly on how and why the information about the importance of sleep really spoke to me as an element of my life that I needed to address, but in this post I wanted to outline other elements of the interview, specifically, I wanted to talk more about the actual health issues associated with skipping a few hours of sleep.
What do you mean when you talk about ‘sleep’?
In the interview, Matthew Walker classifies sleep as being between 7-9 hours of good quality sleep that contains appropriate time spent in each of 4 stages of sleep.
Although all 4 stages of sleep are essential to the quality of your sleep, I wont get into the nitty gritty of how sleep works specifically here, because thats really a few massive posts all on their own, and like you, we only really have time to just hit the high notes here, so yes, I am GROSSLY oversimplifying the whole system here, but here is a general run down.
Stages 1 and 2 are your “set up” stages of sleep, they are the period where your body begins to turn off your monitoring systems and relax, changing your heart rate and breathing to eventually get into deeper levels. This is also the stage where you can have a power nap as long as you don't doze for more than 20 minutes.
Stages 3 and 4 are where you get down into deeper levels of sleep. In Stage 3, your brain waves become very long and slow and become much less responsive and harder to wake up, while your brain “paralyzes” your body in a type of muscular incarceration so that during stage 4, otherwise known as REM (Rapid Eye Movement) sleep, you don't get up and start acting out your dreams…it sounds scary at first but its a handy survival mechanism. You have probably experienced this lock down first hand if you have ever suddenly felt awake at night time but been unable to move your body.
Stages 3 and 4 are where most body replenishment occurs. This type of sleep is excellent for cardiovascular health, metabolism, and most importantly, removal of waste products that accumulate in your brain throughout the day.
OK, get on with it - what health issues does it cause?
Short answer? Heaps. Almost everything in fact. According to Matthew, the shorter you sleep, the shorter your life. Fewer hours of sleep predicts all cause mortality. Put simply, you’ll be dead sooner and the quality of your life will be worse.
Kieran, I want more detail than that…
In the podcast, Matthew talks about the research he has done for his book “Why we sleep” and summarises a few of the more…well lets face it, scary side effects of a lack of sleep.
Some of the issues are more functional than others.
As mentioned in the previous blog, fewer than 6 hours of sleep leads to a decrease of physical endurance and function of 30% due to lactic acid build up as well as the bodies ability to expire our breath, but anything below 7 hours has been shown to impair us, with decreases in our peak muscle strength, peak running speed and our vertical jump.
Coupled with this fact is that according to Matthew, it has been shown that sleep and frequency of injury has a linear relationship, stating that 9 hours of sleep Vs 5 hours of sleep leads to a 60% increase in the probability of injury.
Another more functional element to sleep is that it has been shown to improve learning performance (in rats at least) by 20-30% as it is thought to be the time when our brain strengthens its connections when learning something new.
Have you ever been trying to learn something new or studying and come to a point where you are just stuck so you give up for the night?
If your anything like me, I know that you found that the next morning it just clicked. You were able to get through the whole song you were learning, the language came to you, or you could remember the whole quote correctly.
It appears that the brain literally prunes away the unnecessary elements of the pathways and streamlines your new skill.
This next one really spoke to me also, as someone who has always carried more weight than is strictly necessary, and frequently had a yo-yoing relationship with weight gain and loss, I was surprised to learn that sleep doesn't just help you lose weight, it actually helps you keep it away!
Lack of sleep decreases the body’s levels of a hormone called Leptin, who causes the sensation of satiation (aka - feeling full). At the same time, the hormone Gremlin (the guy responsible for NOT feeling full, and making you hungry), is ramped up.
It has been shown that people who sleep between 5-6 hours a night will eat 200-300 MORE calories a day, equalling roughly 70,000 calories a year, leading to 10-15 pounds (or 4.5-6.8kgs) of obese mass a year.
Worse, you eat more of the WRONG THINGS, going for heavy hitting carbs and heavy processed food, while simultaneously staying away from leafy greens etc.
Matthew claims that if the rise in obesity in last 70 years, is plotted on same graph as amount of sleep in society on average, the lines go in equal opposite directions.
So just to clarify…on average, if you slept more than 7 hours a night, you would eat fewer calories, crave better quality food and with no extra effort or will power necissary, you would have to manage up to 7kgs of fat FEWER, each year.
Do you know any other “magic” weight loss solution that can offer all that with zero negative side effects and at zero cost?
And now, as promised…the scary stuff.
Insufficient sleep according to the podcast, degrades our DNA, specifically it has a negative effect on immune response genes, decreasing their reproduction. At the same time, we get increased chronic inflammation, increased stress response leading to cardiovascular disease and an increase in the expression of genes related to the promotion of tumour growth.
I shouldn't really need to go on about those points but I will.
Matthew claims that this is most exemplified by people who do shift work. Night shift workers suffer from higher rates of obesity, diabetes and cancers, most notably bowel, prostate and breast cancer.
This is apparently so prevalent he states, that the World Health Organisation now classifies night shift work as possible carcinogen in and of itself as 4 hours of sleep even for just one night, causes a remarkable state of immune deficiency, a significant drop in anti cancer cells in our immune system.
But wait, there’s more!
Sleep deprivation affects your sex hormones too, in fact, Men who sleep 5-6 hours a night will have testosterone levels 10 years their senior, a critical element of health, strength, muscular performance etc, in short, it ages you a DECADE.
Consider how you are when you're deprived of sleep; reduced alertness, impulsive, lack of ability to concentrate, difficulties with learning and memory.
Why could this be? What do you think happens to your brain when you are like this for weeks, months or even YEARS on end?
While we are awake our brain builds up toxicity, especially a protein called ‘Beta Amyloid’. You may have hear of this protein before as it is the main mechanism in the development of Alzheimer’s Disease. When we sleep properly, the process of sleep wipes our brain, reducing build up of Beta Amyloid.
Insufficient sleep across lifespan now appears to be one of THE most significant lifestyle factors in determining whether or not you will develop Alzheimer’s disease.
Simply put: wakefulness causes low level brain damage and sleep offers reparatory function.
Matthew offered two real life examples that are suggestive of these findings too. Love them or hate them, Margaret Thatcher and Ronald Reagan have arguably had a huge effect on our world today. They were both known as having strong wills with sharp minds. They were both also famous for getting around 4-5 hours of sleep a night. They both died with Alzheimer’s.
This anecdotal evidence is hardly proof of the research but it raises a few questions about the concept, two people with very active minds and social lives (two factors previously thought to be predictive of the disease) got it anyway.
But Kieran, I’m one of those people who doesn’t need that much sleep…so I’m all good right?
Well…at least its a safe bet that you're wrong anyway.
If you had read Part 1 of this post (seriously, why are you this far in if you haven’t?) you’ll remember that Matthew’s research has shown that people are completely incapable of determining how much they are affected by sleep deprivation.
I was was of you, I was convinced of my own ability to get things done when I was working off lower levels of sleep, but it turns out, like you, I am completely unqualified to make that assessment.
Negative effects of your lack of sleep can ONLY be assessed by external sources and measurements.
“I’ve heard some people just don't need that much though. I bet I’m one of them.”
Again, you're only partially correct.
Although studies show us that there is a population of humans that can function as normal from just 5 hours of sleep, but those same genetic studies show that is a group of less than 1% of the population.
In fact, you're MORE likely to be struck by lightening in your life time than to be one of those people, so you should probably assume that you aren't one of them.
So…what can I do then?
Get to sleep. Seriously, its as simple and as difficult as that.
The minimum you should aim for is 7 hours! 7-9 hours appears to be our sweet spot as humans.
6 ways to improve sleep:
- Regularity; go to bed at same time.
- Decrease light; Try away from screens for at least an hour before bed or at LEAST have your screens on night mode.
- Halve the number of lights on in your home in an evening. Apparently, if you are in an environment with no lights at all, we fall asleep 2 hours earlier.
- Keep it cool, brain decreases temp by 2-3 deg fahrenheit to initiate sleep. always easier to sleep in a room thats too cold rather than too hot. We fall asleep faster and deeper in cold.
- Wear fewer clothes to bed. Again, its a heat thing.
- Try to have warm feet and hands. It helps keep your brain cool as it stakes blood away from your core. You could also try having a hot bath or shower before bed, it brings blood to the surface then your core body temp plummets when you get out of the water and you're more ready to sleep. The reverse is true for waking up, studies have shown that its the rise in temperature in the morning not just the light that wakes you.
This is not an exhaustive list of things you can do to try improve your chances of going to sleep but I like them because they are the classic set you always read. If you have any other tips about sleep we’d love to hear them.
If you have any questions about how your body is working, sleep related or not, always feel free to contact us at Align to discuss your health issues. Its literally what we are here for.
I am going to leave you with a few more things to think about.
Sedation is NOT the same as normal sleep, pills and alcohol might help you nod off but they do not allow you to go through the full normal stages of sleep and so you will miss out on a lot of it’s benefits. Be sure to discuss your inability to sleep with a health practitioner about improving your sleep hygiene as Matthew Walker states in the podcast that sedatives are an absolute last resort.
Sleep is NOT like a bank, you cant accumulate debt during the week and then make it up on the weekend. As humans we've never developed the ability to create a safety net to overcome a lack of sleep as we are the ONLY species that deliberately deprive themselves of sleep for no apparent reason.
Remember too that every day in Australia there are car accidents that are linked to sleeplessness. Drowsy driving is apparently worse statistically than drinking or drugs. In fact according the Matthew Walker, being awake for more than 20 hours makes your brain act like it is over the legal blood alcohol limit for drink driving.
Lastly NO ONE tells you to stay awake on a problem. “Sleep on it” so that you can have a fresh perspective is a suggestion with no cultural boundaries.
Accumulated wisdom for centuries has promoted sleep as a way of better tackling your problems, getting things done and improving your life…do we really think that is no longer true just because television is so much better now?