SLEEP AND YOUR BRAIN
Modern society puts little importance on a good night’s sleep. Margaret Thatcher, known to sleep for only four hours or less a day, is reported to have said “Sleep is for wimps.” We’re busier than ever and a lot of us are attached to our phones even when we’re in bed. Today we get between 90 minutes and two hours less sleep than people did 100 years ago.
You most likely know about the stages of sleep; light sleep, REM and deep sleep. But did you know that your brain waves are basically the same during the first two stages as when you are awake? Only deep sleep produces delta waves. It is during this delta sleep that your body heals and rejuvenates itself. Your immune system is strengthened and growth hormone is released to regrow tissue and build bone and muscle.
Without a doubt though, the most important organ in our body to be affected by sleep is the brain. Poor sleep has a major impact on your mental state – we make rash decisions, our ability to learn is inhibited, long-term memory is affected and we even lose our capacity for empathy. There’s also a direct correlation between sleep and issues such as Alzeheimer’s, cardiovascular disease, stroke, diabetes and mental health problems.
The brain accounts for two percent of the body’s mass yet uses a quarter of the body’s entire energy supply. This energy usage means the cells in your brain have a heavy requirement for nutrients to nourish it and in turn produce a substantial amount of metabolic waste. Your brain uses a deep and complex network of blood vessels to supply nutrients to the brain. In the rest of your body, the lymph system helps to dispose of waste. But it doesn’t extend into your skull so how does the brain deal with toxins? By using that same network of blood vessels to literally bathe the brain. The cerebrospinal fluid (CSF) that fills the space surround it runs along that network of blood vessels, reaching every single cell in your brain. Think of it as your brain being scrubbed clean. Can you guess when this vital housekeeping takes place? Yep, that’s right, during deep sleep when your brain isn’t hard at work and the cells actually shrink to allow room for CSF to move in.
Such an elegant solution to taking care of such a complex machine. How important is this cleaning function in your brain? Some researchers believe that this nightly function could be the reason why we need sleep. And think of it this way; what would your kitchen be like if you stopped cleaning it for a month? Which is a great image to keep in your mind tonight when you climb into bed and reach for your phone!
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