First let’s start with an introduction to the Circadian Rhythm – This is your body clock – One may simply relate it to the ‘daily morning bathroom call’ regardless of where you are! Perhaps, one could even relate it to a jetlag when you travel across the world.
Technically, the circadian system orchestrates metabolism in daily 24h cycles. This phenomenon (chronobiology) is predominantly based on the principle of light & darkness or day & night.
Why do we even need a body clock?
A baby doesn’t have a fully functional circadian rhythm, hence he would sleep at ‘odd hours’ and cry for food other times of the day. If we, as adults didn’t have a clock, we too would either be sleeping or feeding throughout the day.
Thankfully, that is not the case.
Imagine our body to be a self-driven machine. If so, then it would be ON 24/7. Eventually, our bodies would go into an overdrive and crash. Which means, our body would work equally hard even if we were resting.
There are 3 significant zones which affect and build our body clock.
Light and Darkness; Feeding and Fasting & Sleep and Activity
These 3 zones should be in harmony.
Tuning the body clock will develop an efficient version of you, with higher cognition, more stamina and no food cravings! This is done by training one’s body clock to switch certain genes ON and OFF efficiently across 24h cycles so that we are alert during work, feel hungry for breakfast, have ample endurance during a workout, sleep well at night and repeat.
How do we deviate from our body clock? The introduction of artificial light, work at night-time and disrupted sleep patterns cause circadian misalignment.
Evidence has shown a strong connection between the rise in recent epidemics (such as obesity, diabetes, CVDs) and the above mentioned reasons. Resulting in a daily grumble of “I don’t get enough sleep”, “I need more coffee” or “I don’t get quality sleep” at night.
Having said that, how do we reset our biological clock?
We always believed that the same cells which are used for vision (i.e. rods and cones which are light-sensitive cells) also signalled synchronization between our body clock and the sun’s rising and setting.
But what about the blind, who do not have rods and cones?
It is fascinating to know that recent studies on blind subjects have shown that the human eye has two separate light-sensing systems — one that perceives visual signals that allow us to see and a second, separate system that tells our body when it is day or night which is controlled by Sunlight.
In sunlight, one component is the ‘Blue Light’, which is the most powerful resetting button for the circadian rhythm. Exposure to this part of natural light a.k.a. blue light resulted in the shifting of a subject’s body clock by 1.2 hours; with increased alertness (measured by brain alpha wave activity), hearing performance, and the subject’s reported sleepiness throughout the 24h cycle.
That being said, Blue Light is what is emitted by LED/LCD screens and all other artificial lights that we turn on during the day or night, as well. Now, one can easily understand the impact of continuous exposure (<10h) of Blue Light on our Body Clock. With prolonged exposure of Blue Light after Sunset, one is resetting his/her circadian rhythm! This answers any questions about feeling tired when you’re awake or not getting ample sleep at night, wouldn’t you say?
When we fight our biological clocks, it does a lot more than make us grumpy coffee drinkers.
What is interesting is, artificial light is not the only aspect which muddles up our clock. Feeding at day and at night also affects the clock.
We will take up two experiments which will clarify this statement.
In the first experiment, two identical sibling mice were taken in the same natural light/darkness cycle. One mouse was given a healthy balanced diet, the other was given a high calorie diet (more refined carbs & fat). The experiment showed that after a few days, the mouse who ate a healthy balanced diet – ate only during the day. However, the 2nd mouse ate both during the day and the night.
This proved, that light is not the only factor which can affect your clock, but it is also the type of food you consume. A high calorie diet (rich in refined carbs and fats) made the mouse eat again at night, making him fat. The 1st mouse’s clock had efficiently turned the genes ‘ON’ for metabolism which worked only during the day, whereas the 2nd mouse, his body clock turned the genes for metabolising food ‘ON’ again at night or never turned it ‘OFF’.
Now, the second scenario was as follows:
Two identical mice were taken in the same light/dark cycle. One mouse was given the liberty to eat whatever they wanted – whenever they wanted. The 2nd mouse was given a high calorie diet only at night – with a strict time of feed and the calories consumed each time were the same. This experiment showed that the 1st mouse who had no discipline in feeding was 28% fatter than his identical twin and had a fatty liver, whereas the 2nd had more energy, more endurance, a good lipid profile and could complete complex motor control tasks.
This experiment showed that with discipline and training your body clock, one can automatically have more energy, reduce a disease risk and one wouldn’t need to exercise to lose weight, but to stay fit.
Unfortunately, we tend to override the biological clocks in our brains and instead pay attention to the mechanical clocks on our wrists.
I would urge you to be mindful of two things, one, when you want to eat at night, you could have a look at your watch and avoid the indulgence; two, when you want to sleep, start dimming all the bright lights at home, including turning device screens off, an hour or two prior to sleeping.
We will definitely dive deep into the physiological aspects of our circadian rhythm in my next blog. Stay tuned!