Why do we sleep?
The truth is, we’re not entirely sure. We know that sleep is essential to maintaining many of our key functions such as speech, memory and creative thinking, but we’re still not entirely sure why. In 2013, American scientists came up with a plausible explanation which still isn’t fully understood - they found, through an experiment on mice, that during sleep cerebral spinal fluid is pumped round the brain like a washing machine flushing out waste products. Another factor could be brain consolidation - sleep allows our brains to process and store all the information we’ve gained throughout the day.
How important is sleep?
Simply put, it’s essential. While a sleep deficit (not getting enough sleep) can have catastrophic effects such as crashing the car or walking out into traffic, it can also be a long, slow drain on the basic functions of health and wellbeing:
- As we’ve already stated, sleep allows the brain to consolidate and flushes out toxins around the brain that could impair brain function - this leads to healthy brain activity and a more positive, fast-moving mental attitude. That means that a well-rested person thinks better, learns quicker and feels more creative. Poor sleep can lead to depression, failure to maintain relationships and risk-taking behavior.
- Good sleep allows the repair of heart and blood vessels - so lack of sleep can mean an increased risk of heart and kidney diseases as well high blood pressure and stroke.
- Obesity is linked to sleep deficiency too, especially in teenagers. One study revealed that the risk of becoming obese increased with every hour of sleep deficit regularly experienced.
- Sleep supports growth and development - hormones that deliver normal growth and development are triggered by sleep. Children and teenagers who don’t sleep enough may deprive their bodies of the opportunity to develop normally.
- Lack of sleep affects the immune system which protects us against outside threats. The better our sleep patterns, the more easily we fight common infections.
How much sleep do I need?
Sleep needs vary as we grow - newborns need 16-18 hours out of 24, while pre-school children require 11-12 hours in the same period. School-age children need a minimum of ten hours sleep every night, and teenagers aren’t far behind with 9-10 hours required. Adults generally benefit from 7-8 hours sleep, whilst seniors may find their sleep needs reduce to just seven hours.
So if sleep is so vital, how do we ensure we get a good night’s sleep?
There are many ways to improve our quality and quantity of sleep;
- Reduce screen time - set an alarm to turn off computers and TVs an hour before bedtime to allow your brain to adjust. You can also get apps that change the ‘blue screen’ color to a more orange hue as the evening advances - blue screen is known to keep the brain active, hindering good sleep.
- Cool it - a cool, dark bedroom will help you sleep longer and more deeply. Buy some blackout curtains and add extra bedding rather than overheating your bedroom.
- Decaffeinate - it’s obviously really. If caffeine wakes you up, it’s a seriously bad idea when you want to sleep! For some of us that means cutting out caffeine after lunch, for others it means rescuing our overall caffeine intake by replacing coffee, tea or energy drinks with caffeine-free drinks.
- Get out more - exercise in the daylight has two effects: it makes us more tired, which means we’re more likely to sleep well, but also daylight also affects our ‘brainstem switch’ a neural function that appears to need daylight to activate it, so that later in the day it can ‘switch off’ our wakefulness, helping us sleep better.