Sleep, the golden elixir of life, yet so many of us are chronically sleep deprived. While it would take 6 months of total sleep deprivation to actually kill you, the detrimental effects can be felt from as little as 1 nights poor sleep.
The focus on sleep by the biohacking enthusiasts in Silicone Valley is increasing as they realise the cognitive boosting powers it elicits. So much so that by 2020 the 'sleep tech' market is predicted to be worth 81 billion dollars as people try to optimise their sleep quality.
So why is sleep so important?
With regards to diet and exercise, when you try to lose weight when in a sleep deprived state, 70% of your weight loss will come from muscles mass rather than fat. Your body clings onto fat, precisely what we don't want as this loss of muscle mass leads to more weight gain as our basal metabolic rate decreases (amount of calories burnt at rest).
Not only this, as our sleep decreases so does our motivation to exercise. We will perform at a lower intensity making our workouts less efficient. Even more worrying is that as our sleep quantity decreases, our risk on injury increases. Sleep is also vital for recovery which has been hypothesised as a reason why we sleep better after exercise (although not too seen before bed, which I shall discuss in my next blog post).
Sleep impacts on our hunger and satiation hormones, ghrelin and leptin respectively. When participants of a study were sleep deprived so that they only had 5-6 hours per night for 1 week, their leptin levels decreased whereas their ghrelin levels skyrocketed. These participants consumed 200-300 more calories per day simply due to a lack of sleep.
Sleep isn't just important for helping us maintain a healthy weight, it is also vital for our overall health. When ordinarily healthy individuals were sleep deprived for 1 weeks (6 hours per night), their blood sugar levels were so disrupted that they would be diagnosed as pre diabetic.
Sleep also impacts on our cardiovascular health and every year this is proven in the statistics across the nation when it comes to daylight saving hours. When the clocks go forward and we lose an hour, the incidence of heart attacks increases by 24% and when they go back, they drop by 21%. This is just from 1 hour!!
Sleep and immunity are also intrinsically linked. A study researching the link between immune health and the common cold found that when we are sleep deprived (5 hours or less), we are 4 times more likely to catch a cold. Even more astounding is that when we have 4 hours or less for just one night, there is a 70% drop in anti cancer fighting immune cells known as 'natural killer cells'. These studies show how important sleep is to maintaining good health and fighting disease.
The final area I want to touch upon is that of mental health. There is no psychiatric condition in which sleep is normal. Our emotional brain centre (the amygdala) is 60% more reactive when we are sleep deprived. We are also much more emotional and impulsive when we haven't slept well. I know that when I am tired I can't cope with small things going wrong and tend to overreact to stressful situations that usually wouldn't faze me.
Sleep deprivation can also exasperate conditions such as depression and anxiety. There is an intimate relationship between mental health and sleep health and given we have become a sleep deprived nation there is little wonder that 1 in 4 people are now diagnosed with a mental health condition.
Shorter sleep results in a shorter life expectancy.
Now that I have scared you with the science behind why you should be getting more shut eye, how can we improve our sleep? Well, check in next week and I will give you some tips on how to improve your chances of getting a good nights sleep.
This information is taken from a podcast with Dr. Chatterjee & Dr. Matthew Walker, to listen in full head to #27 Why We Sleep with Matthew Walker PART 2 from Feel Better, Live More with Dr Rangan Chatterjee in Podcasts. https://podcasts.apple.com/gb/podcast/feel-better-live-more-with-dr-rangan-chatterjee/id1333552422?i=1000416096496