Why we’ve gotta get our sleep right
Did you know that chronic sleep deprivation is very much like having mild jet lag ALL the time?
If you’ve had jet lag before you’ll agree that it’s not much fun.
The reason we don’t notice the similarity is because a) it’s mild but constant, and b) it’s become a default state for many of us.
Let’s define sleep deprivation. If you get less than 7 hours per night on a consistent basis, you can safely say you’re sleep deprived. The other factor involved in sleep deprivation is sleep quality. Unfortunately this is not as straightforward to define or determine.
Sleep deprivation is wreaking havoc on our health as a society, and sadly it’s ignored or just mis-understood as an important factor for a healthy lifestyle.
I wrote a post earlier about the 5 pillars of health and weight loss. In this, sleep took number 1 position. Today I want to bring more focus to the importance of sleep and how ignoring it will make us fat and sick.
We all run on the same clock
We’ve got a biological clock in our brain. It regulates our wakefulness and sleepiness consistently with the rise and fall of the sun.
When the sun rises, light enters the eyes and gives our brain the “wake up” signal. A sequence of hormones are stimulated for the engines to fire up. Heart rate and blood flow increases, metabolism is initiated and brain activity heightens.
As we arrive at the end of the day, the absence of sunlight stimulates the release of melatonin, the hormone responsible for drowsiness and eventual sleep. Basically, the reverse occurs from a physiological perspective.
This undulating cycle is our sleep-wake cycle or scientifically known as the “circadian rhythm”. A healthy cycle should look a little like this:
We can see the distinct variation between wakefulness and sleep. Unfortunately due to our environment we tend to have a rhythm that looks more like this:
The curve is flattened, which means we’re not achieving the peaks in alertness and productivity we could be, nor are we dipping into the deep valleys of rest and regeneration that our brain and body needs.
We’re just hovering along exhausted and unhealthy.
Cortisol is a key hormone in initiating wakefulness and peak energy during the day. Typically cortisol secretion would be switched off after dark and melatonin would then take over.
Since the introduction of the light bulb, this is no longer the case. More over, with smart phones, TVs and laptops as today’s norm, our sleep hormones are out of whack and sleep-wake cycles the worst they’ve ever been.
Let’s delve into what’s really at stake when we deprive ourselves of the sleep we need.
The health affects of sleep deprivation.
Sleep neuroscientist Russel Foster in his 2013 TED talk says that 5 hours or less per night provides a 50% likely-hood of being obese.
Studies show that levels of the hunger hormone, Ghrelin is elevated and the satiety (feeling full) hormone, Leptin is lowered in subjects with poor sleep-wake cycles.
This disruption causes the brain to scream for energy dense foods such as sugars and fats, contributing to long term obesity. This is not just upon rising, but throughout the day as well.
Sleep is so important for a healthy heart. Sleep deprivation is linked to higher risk of high blood pressure and cardiovascular disease, regardless of healthy food and exercise habits.
We mentioned cortisol contributes to wakefulness. It’s also the fight or flight hormone. If secreted at night it’s actually alerting our body to start preparing for danger when there isn’t any. We don’t need this at night.
Increased heart rate, blood vessel narrowing and elevated blood sugar levels are the primary responses to cortisol. This is the perfect recipe for high blood pressure, and eventually heart disease. It means thicker blood flowing through narrower arteries and the heart working MUCH harder than it needs to.
Type 2 diabetes
Thanks again to our friend cortisol, we find ourselves at a higher risk of Type 2 Diabetes as well.
We know cortisol elevates blood sugar levels. It also increases insulin resistance. This means while insulin is trying to transport glucose to the cells, the cells just don’t want to know about it. Word gets back to the pancreas that the glucose wasn’t delivered, so it sends more insulin into the blood stream.
On the long term, the pancreas becomes over worked and can’t keep up the demands of insulin production. Our cells become starved of their fuel source and the blood stream is left with excess glucose. Here, we can also see the link between diabetes and heart disease.
People with mental health disorders have historically exhibited sleep deprivation and even insomnia. Recent studies have looked at the relationship in the reverse, where sleep abnormalities could be contributing to or causing mental health disorder.
Depression, anxiety and bi-polar are the common mental health disorders linked to sleep deprivation. Most of the research around this shows strong correlation rather than direct cause.
It could be that lack of concentration and productivity indirectly contributes to greater stress levels. It could also be that elevated cortisol and an imbalance in brain chemicals result in altered mood and mental health disorder.
Low Immunity & Cancer Risk
Sleep deprivation is linked to lower immune function and cancer risk. Research shows that there’s a physiological relationship between the nervous system and the immune system. These systems are in constant communication with each other through hormones and chemicals.
A well rested body will have smooth communication between systems ensuring the immune system works diligently to clear bacteria and toxins. Poorly rested bodies remain vulnerable to the risk of infections, virus and even cancer.
Prolonged immune deficiency has also been linked to low-grade inflammation which is associated to (lo and behold) Type 2 diabetes and cardiovascular disease.
Now it’s not all doom and gloom. If your diet and exercise is adequate, but you’re still finding you’re getting sick or finding it hard to shift weight, restoring the sleep-wake cycle will be a game changer.
Thankfully there are steps we can take to achieve better sleep health. In fact, here’s a post I prepared earlier – 5 steps to improve sleep and health
’til Next time
Like an Oak, we grow slowly but surely
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