Last update: 06 November 2017
Even if our lifestyle allows us to extend the day up to times that were once unthinkable, synchronizing our biological clock with the natural alternation of light and dark is essential to keep the body healthy.
Light has always been associated with positive emotions. In summer, when the days are longer and therefore there is more light, happiness seems to multiply. There are no moments more memorable than those we spend on wonderful sunny days by the sea, during a picnic in the mountains or enjoying the sun on a terrace.
Summer and spring, with their light, are periods of expansion, during which we venture and explore. Autumn and winter, on the other hand, with their rains and shorter days, push us to take refuge in the house.
Our body, which is part of nature, perceives the changes in the context in which we find ourselves and, through physiological mechanisms such as the secretion of hormones, makes us feel more or less energetic according to the cycle or phase in which we find ourselves.
As well as our mood and ours energy fluctuate with phases, they do so even with shorter cycles, like those of night and day.
Light and the biological clock
The hypothalamus is a small region located deep inside the brain called the reptilian brain. It is a fundamental structure that takes care of regulating fundamental processes for life, such as body temperature, food and liquid intake or libido, as well as regulating emotions. We feel hunger or satiety, anxiety or tranquility depending on the hormones that this part of the brain secretes.
Like everything that has to do with the brain, the hypothalamus is a very complex structure, but it is known for certain that one of the factors that have a decisive influence on its function is the light it perceives from the environment.
The brain has developed at the hands of nature, therefore during the day, when it is flooded with sunlight, it understands that it is the time for activity, while at night, when it gets dark, it perceives that it is the time for rest and regeneration. These days, however, these times are not fixed. With artificial light we can stay awake even long after sunset.
This alteration of natural cycles disturbs our biological clock and affects our health.
Failure to respect natural cycles harms health
Our body, our biological clock, is designed to respect the cycles of light. During the day it is necessary to receive sunlight to maintain optimum energy levels. Artificial light is not a substitute for sunlight. This is why, in many cases, fatigue takes over and we feel we need a coffee to be able to keep up with the rhythms.
Long-term, a deficit of direct sunlight increases the risk of suffering from depression. This is why, in winter, when the days are shorter and we leave work when it is already evening, it is much more frequent to suffer from depression. The sun is also the most important source of vitamin D, which is essential for fixing calcium in the bones.
Another of the most astonishing examples of the power of light over our bodies concerns the way we wake up. We usually schedule the alarm at a certain time in the morning and, therefore, our sleep is interrupted abruptly. We turn on the room light, passing from the darkness of the night to the light of day in a few seconds.
In nature, sunrise occurs progressively and our brains are programmed to wake up in this way. With the gradual increase of natural light, the brain gradually awakens, leaving the dream world. Not respecting it is the reason why we would stay in bed and have so much trouble getting started in the morning.
In addition to the sleep we get when we get up, this way of waking up makes us tired throughout the day, as well as provoking us one underlying stress, because the natural processes of sleep, necessary for a good rest and to regenerate ourselves, have not occurred correctly.
Adjust the biological clock
There are some things we can do to regulate our biological clock:
- Try to harmonize our schedules, as far as possible, to natural cycles, listening to our body. Some people are more active in the morning, while others are more active in the evening, but staying up late into the night is never good.
- During the day, make sure you spend as much time as possible in natural sunlight. Since it is complicated with the routine of modern life, try to get direct sunlight at least half an hour a day.
- Make the environment around you be il as dark as possible before falling asleep. Turn on as few lights as possible, and if you can, it would be best to avoid light screens.
- Try not to wake up abruptly. Since it is almost impossible to wake up in the natural light of dawn, as it is not in line with our schedules, a good solution to this is the so-called "gradual" alarms. They are alarm clocks that light up the room progressively until the time we need to wake up, imitating a real sunrise.