Our sleep patterns have become so bad that the world health organisation (WHO) has now declared a sleep loss epidemic throughout developed nations.
Today, 2/3 of adults in developed nations do not obtain the recommended 8 hours of sleep per night.
By routinely sleeping less than 6 or 7 hours a night, you could be potentially damaging your immune system, and more than doubling your risk of cancer, and it’s a Key lifestyle factor for developing Alzheimers.
You’re impairing your ability to concentrate drastically, harming your ability to form memories and making yourself more likely to lose control emotionally. Maybe its time we understood why sleep is so necessary and what happens when we don’t get enough.
How does a lack of sleep affect us?
Lack of sleep can have detrimental effects on all aspects of our health; it's hard to stress how badly we need to take it seriously without coming across as an pest.
Too little sleep is one of the major causes of our overeating. We eat more when we are tired because too little sleep jacks up concentrations of a hormone that makes you hungry and quashes a companion hormone that makes you feel full, making it a proven recipe for weight gain.
So detrimental is sleep deprivation to our health that the Guinness world book of records has stopped people trying to break the world record for sleep deprivationand its easy to see why with sleep deprivation connected to Alzheimers, anxiety, depression, bipolar, suicide, stroke and chronic pain as well as cancer, diabetes, immune deficiency and weight gain.
One brain function affected drastically, even by a small amount of sleep deprivation is concentration. One study showed that participants would occasionally stop responding to stimuli when sleep deprived due to participants entering into ‘microsleeps’ in attempt to fill the sleep deficit.
After three nights of sleep deprivation participant’s concentration was impaired by over 400%. After 4 hours of sleep for six nights, participants also showed a 400% decrease in concentration. Individuals who obtained 6 hours a night showed that reductions in concentration could reach the levels of the other two groups if left unchecked. This is worrying as so many of us today are only sleeping for 6 hours a night. However, we do acclimatise to reduced levels of sleep perceiving lower alertness and poor concentration as the ‘norm’ often going under the radar and harming our overall health.
The reason some people want to kill noisy eaters…
Its well known that a lack of sleep can make anyone a bit cranky. It’s also well known that if you tell them they need to get some sleep, they’re likely to get even angrier.
The reason we can become so irrational when we don’t get enough sleep is because the amygdala, which is a key hotspot in the brain for triggering emotions shows a 60% amplification inactivity in sleep-deprived individuals.
A full nights sleep allows the part of the brain known as the prefrontal cortex (PFC), which is responsible for rational and logical thought to become strongly connected to the amygdala. Without sleep, the strong connection is lost, and the amygdala can ‘take over’ preventing the PFC form stopping the amygdala becoming the boss. This is what leads us to react irrationally.
All this being said, if you smack your lips when you eat, you need to take a good look in the mirror and have a quiet word with yourself.
How does sleep aid memory?
When we are carrying out any fact-based learning, the memories are stored first in the short-term storage space in an area of the brain called the hippocampus. Sleep plays a critical role in turning these short-term memories into long-term memories.
One study on university students found that memory formation was impaired by 40% and ability to take in information was also impaired. This could be the difference between a good grade and a bad one.
During the lighter sage of sleep, N REM sleep to be specific, short bursts of electrical activities occur called ‘sleep spindles’ which shift the memories from the hippocampus into the long-term storage space in the cortex. There is also a loop of electrical activity that occurs on repeat every 100 to 200 milliseconds between the hippocampus and the cortex, which also helps move the memories.
In addition to moving the short-term memories to long-term memories more effectively, it also clears out the short-term storage space, so we are ready to learn the next day again. So adequate sleep not only affects our ability to form long term memories but also affects our ability to create new memories.
As we age, it becomes harder to create and store new memories and we now that part of this is becauseseniors are unable to generate spindles to the same level as young adults, suffering on average a 40% deficit.
So should we nap more?
During one study, when participants undertook a task designed to tax the hippocampus; one group, ‘the nap group’ took a siesta for 60 mins, and the no-nap group were made to play board games. Afterwards, they both undertook more learning. Those who didn’t nap became progressively worse at taking on new information; those who did nap improved their ability to learn.
What governs our sleep mechanisms anyways?
There are two systems in control of our sleep functions. You have probably heard of the first one, the circadian rhythm.
What is the circadian rhythm?
When we wake up in the morning, we start to produce serotonin, the neurotransmitter responsible for wellbeing, and this helps us to feel more alert. After roughly midday, we begin to decrease the amount of serotonin we produce and start to produce more melatonin, which is responsible for making us feel sleepy. Interestingly around midday, when the two are relatively balanced, this can cause an adverse effect, making us feel more tired.
Adenosine controls the second system that regulates sleep.
From the moment we wake up, a chemical called adenosine starts to build up in the brain the more Adenosine in the mind the more significant the ‘sleep pressure’ is, giving us the feeling that we need to sleep. The longer you are awake, the more adenosine you make, which means you are creating an increasing desire to sleep. High concentrations of adenosine calm the activity of wake-promoting regions of the brain and increase the activity of rest promoting regions. This runs separately to the circadian rhythm but is just as important.
The big coffee question
Do you know what the most widely used and abused psychoactive component in the world is?
The long-standing question of whether caffeine messes with our sleep has an obvious answer. Yes.
Caffeine battles with adenosine to attach to adenosine ‘welcome sites’ or ‘receptors’ in the brain; however, they interact entirely differently with the Adenosine receptors. Caffeine does not stimulate the receptors, in the same way, meaning we do not get tired.It acts as a masking agent, as well as causing us to enter a more ‘excited’ state of mind.
Caffeine takes a long time to disappear from the brain, and sometimes its effects can take a long time to kick in which is why we don’t always link poor sleep and the coffee we had with dinner. It not only stops us falling asleep quickly, but it also makes our sleep quality poor throughout the night. To add insult to injury, decaffeinated coffee doesn’t always mean caffeine-free. Decaf coffee has 30–40% the amount of caffeine as caffeinated coffees, meaning it can still have a significant impact on our sleep quality, furthermore, the older we are, the longer it takes to remove caffeine, so the more it affects us.
Why is it that a pianist couldn’t play a piece of music correctly until he’d been to sleep?
Mathew Walker, the author of ‘why we sleep’, was giving a talk about sleep one day, when a member of the crowd approached him and told him that he was a pianist and that on numerous occasions whenever he was struggling to play a piece of music correctly, when he woke up the next day he could play the part without making a single mistake. This piqued his curiosity, and he began to look into it further.
In a study, right-handed individuals were asked to type out learned number combinations with their left hands. The participants improved as they practised, but then they were split into two groups and taught new combinations to type; one group was tested 12 hours later in the same day, the other group were taught the combinations and then allowed to sleep that evening and checked the next day.
Those who’d remained awake showed no improvements. However, those tested after sleep showed a 20% increase in performance speed and a 35% improvement in performance accuracy. Practice doesn’t make perfect but practice followed by eight hours of good quality sleep does.
From a brain scan, he saw that the motor memories were being shifted over to brain circuitry that operated below the level of consciousness, which lead to the new skill actions becoming instinctual habits, making them second nature. The type of sleep responsible for this is stage 2 n-REM sleep, so again those sleep spindles play a massive role here, and we know now that more sleep spindles will occur in parts of the brain that have been worked the hardest during the day.
This type of sleep usually occurs during the later stages of our sleep, the period of sleep most people cut short. If you don’t snooze, you lose. Usain Bolt has been known to take naps before races, which the studies show may help improve the muscle memory and motor function. When you consider that decent sleep also offers improved cardiovascular and muscle function, respiratory capabilities, ability to deal with lactic acid and our abilities to keep ourselves cool, it becomes clear that sleep is vital for peak mental and physical performance.
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