We all know that being exposed to bright screens at night, such as a smartphone, is not very advisable to be able to go to sleep. It alters the quality of our sleep and can then affect our physical and psychological well-being.
However, most of us use cell phones anyway, even using them in bed until the last moment before going to sleep. The use of smartphones is so normalized and established in our lives that at night, in the moments we have to rest before going to sleep, it is difficult for us not to entertain ourselves with it.
Why not use your smartphone before going to sleep?
The repercussions of this nighttime use should not be ignored. For this reason, a recent study has focused on analyzing the effects of the smartphone based on its light and the difference between adults and adolescents. In this article, I describe its results, but first, I will give you a little context, explaining what melatonin is.
What is melatonin?
Melatonin is commonly called the sleep hormone, since its function is to increase drowsiness and induce sleep at night. This way, regulates the sleep-wake cycle, adjusting it to the natural day and night cycle. And how does he do it?
Melatonin is secreted by the pineal gland, depending on the amount of light our eyes capture. Specifically, the less light (and more darkness) there is, the more melatonin is produced and, therefore, the more sleep it makes us; and vice versa, the more light (and less darkness), the less melatonin is secreted.
This information is sent to the hypothalamus, the director of our basic functions and our biological clock. This gives the order to the pineal gland to start or stop secreting melatonin, as appropriate.
Therefore, in dark environments it is easier for us to become sleepy and tired, while in a bright room it is unlikely to happen to us. But to what extent does light perception influence melatonin production? You can imagine why you shouldn’t use your smartphone before going to sleep.
Effects of using the smartphone before going to sleep
There are numerous studies that have sought to evaluate the consequences of using mobile phones and other electronic devices before going to sleep, focusing among others on how it influences melatonin. This is because today’s smartphones have LED display lights, which project short wavelength light (between 400 and 500 nm), commonly called blue light.
Usually, this type of wavelength alters our secretion of melatonin, even if its focus is a screen as small as a cell phone. Consequently, A night or sleep light function has been created in many electronic devices, which turns the screen into an orange tone.
This feature applies a filter to block blue light, with the aim of reducing sunlight radiation and its effects on our eye health and sleep hygiene. And does it serve its purpose? Well, a study has been carried out, recently published, in which this effect is analyzed, among other variables.
The objective of the study is to analyze how reading affects sleep quality and its functions, comparing: on a smartphone with the blue light blocking filter, without the filter and a printed book. To do this, a sample of 33 adolescent men and 35 adult men was obtained, in whom sleep parameters and melatonin levels were measured for 14 days, 3 of which performed the experimental task of reading.
By carrying out this experiment, it was observed that reading on a mobile phone at night, both without a filter and with a filter, reduces the usual melatonin levels in adolescents and adults. It should be noted that using your smartphone without a filter suppresses melatonin more than reading with a filter on your cell phone or reading in a printed book.
The most interesting finding is that there are differences between adolescents and adults when it comes to recovering melatonin after a period of time without using these devices. After 50 minutes without using a smartphone (with or without a filter), the adolescents showed a fairly considerable recovery in melatonin levels, with the effects of light screens becoming non-significant.
Instead, adults still had low melatonin levels 50 minutes after cell phone use, which continued until bedtime. Furthermore, the influence of light was even more noticeable when there was no filter applied. Added to this is that only adults showed sleep disturbances, specifically a slight reduction in deep sleep (N3).
Although the results are relevant and solid, the study is not without limitations. First, because they analyzed many parameters of sleep and it requires a laborious process, the expectations of people to be covered had to be reduced. In this way, the sample is relatively small, being only 68 people.
Likewise, the effects of smartphones on women were not evaluated. They were excluded from the study because it was considered that gender differences could interfere with the measures of light sensitivity, sleep physiology, and circadian rhythms, and would make the intended analyzes difficult. This exclusion means that the results cannot be generalized to more than half of the population.
On the other hand, even if we tried to replicate natural conditions of how smartphones are used, the experimental task may not be representative of the real use that we give to mobile phones: we do not usually simply read on our mobile phones, but we usually use them to view content. , playing or using social networks, which are much more stimulating and attractive activities.
Something similar happens with the time between using the smartphone and going to bed. It’s not usually almost an hour that passes after we put down our cell phones and go to sleep, but rather it’s usually less time and we even use them until late at night.
Why shouldn’t I use my smartphone before going to sleep?
In conclusion, it is not advisable to use your smartphone just before going to sleep, since makes it difficult to fall asleep, and even if you are an adult, it may affect the quality of sleep itself.
These effects can imply, in turn, physical and psychological problems, such as fatigue, tiredness, problems with the immune or blood system, irritation, difficulties concentrating and thinking, susceptibility, etc.
All this because the blue light from cell phones alters your melatonin levels, even if a filter is applied. Added to this is that screens not only affect sleep, but also the health of our eyes, and can cause vision problems and visual fatigue.
As you have seen, if you are a teenager, you need at least an hour to recover sufficient melatonin levels to fall asleep efficiently. On the other hand, if we are adults, we need a little more time. As a general tip, I recommend replacing the use of cell phones with relaxing and pleasant activities, such as reading, but in a good printed book.
