It was believed for the longest time, and is still considered by many, that sleep is essentially a waste of time. It’s an indication of laziness or lack of ambitiousness. The popular mantra was that to make the most of our life and the time we are given on this planet, we should sleep as little as possible.
And for most of us, it’s not like we don’t want to sleep, but the fast lifestyle we have chosen for ourselves and the challenges of meeting the demands of our professional and personal lives, keep us from getting adequate sleep every day, which is at the least 8 hours every night. This is especially true in case of developed or developing nations. The severity of the problem has been recognized by WHO in that they’ve declared a sleep loss epidemic throughout industrialized nations.
In not giving your body sufficient sleep, you are not making the most of your life. But, rather cutting it short. Consistently getting less sleep adversely affects your immune system, increases the risk of diseases such as cancer, Alzheimer’s and other cardiovascular diseases, and can also disturb the blood sugar levels.
Sleeping for 8 hours, on the other hand, not only reduces the likelihood of above problems but it restores your body— every major organ and process within the brain—so that they continue to function to their optimum capacity. So, along with balanced diet and exercise, sleep is right up there on the list of top three things you can do for a healthy, long life. Yet, we don’t talk about sleep as often as we should while having conversations regarding health and fitness. And this should change, for it is one of the simplest, easiest and the best gifts you can give yourself health-wise.
So, how do you fall asleep?
How does your body come to know that it’s time to sleep? Sure, the darkness outside is an indication. But, there’s something else that happens inside your body. According to the book, Why We Sleep, written by the sleep scientist Mathew Walker, there is a biological clock inside your brain that dictates your circadian rhythm, that is, your sleep and wake cycles. That clock is the suprachiasmatic nucleus, pronounced as soo-pra-kai-as-MAT-ik situated in the middle of your brain. It sends a signal throughout your body indicating the sleep time with the help of a hormone called, Melatonin.
Melatonin, also called as “the hormone of darkness” or “the vampire hormone” is released into the bloodstream by the pineal gland in the brain, after receiving orders from the suprachiasmatic nucleus. The presence of melatonin is an indication to your brain and body that it’s time to sleep. Melatonin increases in concentration in the blood and peaks around 4 am when one is sound asleep. After this, the pineal gland slowly reduces its release, stopping it completely in the morning telling your body it’s time to wake up.
However, it must be noted that Melatonin itself doesn’t bring about the occurrence of sleep. It just tells your body that it’s time to sleep. Therefore, melatonin medications don’t directly induce sleep but create a placebo effect which can indirectly help an individual fall asleep.
Sleep and Caffeine
While melatonin levels are one way of signaling sleep time to your body, there’s another indicator called Adenosine. It’s a chemical that builds up over time, starting from the time you wake up. This means this chemical exerts pressure or increases in concentration as your waking period increases, which in turn increases your desire to sleep. This occurs due to certain receptors in the brain which are stimulated by adenosine.
The antidote to adenosine is caffeine. Now, when you consume coffee, the caffeine blocks adenosine from its receptors and therefore stops the sleep signal that the brain receives. That’s why after drinking coffee, you feel more alert and active, even if you’ve not slept for the past 16 hours or more.
The effect of caffeine lasts for hours. The half-life of caffeine is 5-7 hours, which means it takes that much time to get rid of 50% of the caffeine in your system. If you have coffee in the late evening, it’s only natural that you’ll find it difficult to fall asleep during the night, as your brain is still experiencing the effects that caffeine induced in the brain 6-8 hours before.
So, the next time you decide to have a cup of coffee, stop to think what time of the day it is. And how long its effects will last. Sleep is arguably the easiest thing you can do to promote good health. So, why not take complete advantage of this powerful tool we have at our disposal every single day!
References and Additional Read:
Book – Why We Sleepby Mathew Walker