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  • Carla Evans

Sleep - I underestimated you

Hi everyone,

We all know the four main lifestyle factors that influence our health. Food, movement, sleep and a sense of connection to something greater than ourselves (community, nature or spiritual connection). They are all EQUALLY important.

Today we're talking about sleep. We probably all know we need a certain amount of sleep and we know how we feel if we don't get enough sleep. I love sleep - I do best with 9 hours a night (hubby will attest to that!) but even I didn't realise just how significant sleep is for our health. Here are a few statistics I've recently learned from the Rich Roll podcast with neuroscientist and sleep researcher, Matthew Walker: (word of warning - it's a 3 hr podcast so you might fall asleep listening to it! Just joking - it's actually very interesting all the way through but might take a few drives/walks to finish :)

  • 1 in 3 people are not getting enough sleep regularly.

  • With daylight savings, when we lose 1hr of sleep there is a 24% increase in heart attacks the next day. In Autumn when we gain an hour, the reverse happens and there is a 21% decrease in heart attacks the next day.

  • Heart disease - in general people who have less than 6hrs sleep a night have a 200% increased risk of cardiovascular disease in their lifetime. A study showed just this - over 5-6 years people with no initial signs of cardiovascular disease but who had less than 6hrs sleep per night on average had a 200-300% increased risk of calcification of a coronary artery at the end of the study.

  • In the first half of your sleep your sleep cycles will contain mostly deep non-REM (rapid eye movement) sleep. In the second half of your sleep you will do mostly REM sleep which is when we dream.

  • Limit a healthy young male to 4-5 hrs sleep for a few nights and their testosterone level will drop to that of someone 10 years their senior.

  • With the same sleep deprivation over 4 nights, blood sugar levels would be disrupted significantly and they would now be classed as pre-diabetic.

  • A study showed that when people were limited to 6hrs of sleep for one week 711 genes were distorted in their activity - half over-expressed (related to tumour promotion growth, cardiovascular disease and metabolism) and half under-expressed (related to immune system).

  • Limit us to 4hrs sleep for one night and our natural killer cell levels drop by 70% (critical for neutralising cancer cells).

  • If you are trying to lose weight and are sleep deprived, the weight you lose will be 70% lean muscle mass rather than the fat you actually want to lose.

Phew - I had definitely underestimated how significantly sleep can affect our health in even a short space of time. It reinforces the need for awareness - if I've had a bad night's sleep, I need to be more aware of looking after my immune system by eating well and taking supplements, I'm not going to push my cardiovascular system by doing intense exercise and ensure I meditate and so on.

The podcast goes on to talk about sleep and alzheimers, addiction, mental health, teenagers and much more.

Here are some recommended guidelines on sleep for different age groups:

Sleep tips:

Temperature - 18 degrees celsius is the optimal temperature for sleep. The body needs to drop in temperature by approximately 1 degree celsius to kickstart sleepiness.

Regular sleep time - where possible keep to a consistent sleep time and wake time throughout the whole week. If you have trouble falling asleep avoid napping during the day. If you do feel like napping helps, take a nap straight after lunch.

Light - have proper curtains/blinds that block light or wear an eye-mask to help induce your melatonin production (sleepy hormone). In the couple of hours before bedtime turn off as many lights as possible in the house. In the morning get as much natural light as possible - even if it's sitting by a window to help regulate your circadian rhythm.

Caffeine - the average half-life of caffeine in the blood is 5 hours. This means if you have a coffee at 3pm, there will still be half the caffeine in your blood at 8pm at night and a quarter of the caffeine at 1am in the morning.

Alcohol - alcohol is a sedative. You may fall asleep easily after a couple of glasses of wine but once the sedative effects has worn off (adenosine boosting effect) you may find you wake up and struggle to get back to sleep.

It's also helpful to know whether genetically you are a night owl or an early bird or somewhere in between. If you have flexibility you can then manage your time in a way that suits your body. Here is a quick quiz you can take to clarify your chronotype:

Another good source for information on sleep is

Matthew Walker's book is called "Why We Sleep" if you want to dive in a bit more!

Happy sleeping!

Carla :)



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