Doctors explained the effect of office light on health
Office lamps by themselves do not "break" hormones, but a dim day and a bright evening can knock down the internal clock. Therapist, neurologist Irina Bespalova and internist Olga Chistik told Izvestia on November 13 about how light affects sleep, metabolism and well-being.
How light controls the internal clock
There is a center in the brain that coordinates the body's work with the alternation of day and night, the suprachiasmatic nucleus. It can be represented as the main internal clock.: they affect the time of falling asleep and waking up, the production of melatonin, body temperature and the level of wakefulness. The main reference point for this watch is the light that gets into the eyes. It is captured not only by the cells that make us see objects, but also by special photosensitive retinal cells that help the brain distinguish day from night.
"Light helps the body to understand when it's day and when it's night. Through the eyes, this signal enters the brain and adjusts the internal clock. Melatonin usually starts to rise in the evening, and cortisol is higher in the morning and decreases in the evening," said Chistik.
In the office, this picture can change: even if it seems that the room is bright, the illumination there is usually much lower than that of the street, and the eyes quickly get used to such conditions. As a result, the brain receives a weak light signal during the day, and late at night, on the contrary, it is too noticeable due to the bright overhead lights and screens. If a person sits in a dim office all day and stays in bright light for a long time in the evening, the habitual rhythm shifts, and it becomes more difficult to fall asleep and wake up on time.
Melatonin production is suppressed primarily by light in the evening and at night, and the lack of daylight weakens the signal that helps the body maintain a daily routine. The spectrum also matters: cold light with a higher proportion of the bluish component has a stronger effect on the internal clock, but during the day it can help maintain wakefulness, and it becomes undesirable especially late at night.
How does lighting relate to metabolism and well-being
Light affects wakefulness not only through sleep: bright lighting alone can temporarily increase activity and improve reaction speed. In dim light and monotonous work at the computer, fatigue is felt more strongly. If a person spends little time outside, falls asleep late and constantly changes the time of rising, the quality of night rest deteriorates, and the next day it is more difficult to keep attention and switch between tasks.
"Glucose metabolism also depends on the time of day. When the internal clock fails, cells may respond worse to insulin, a hormone that helps them absorb sugar from the blood," explained Chistik.
At the same time, neither insulin resistance nor elevated cortisol can be determined by fatigue in the office, and daylight lamps themselves do not mean that a person will necessarily have a hormonal disorder. Similar complaints are caused by chronic lack of sleep, stress, lack of mobility, stuffy room and strain on the eyes.
Bespalova called the statement that the combination of a dim day and bright screens in the evening inevitably "knocks down serotonin" and provokes headaches too categorical: the effect of evening light on melatonin and falling asleep time has been much better studied, and glare, a sharp contrast between a monitor and a dark room, flickering lamps and prolonged neck muscle tension are more often provoked by headaches.
What to change in the office and at home
According to Chistik, you can start with a regular walk during daylight hours: walk part of the way to work, go outside at lunchtime, and if possible sit closer to the window. Morning light is especially useful for maintaining the usual sleep and wake times. At the same time, you do not need to make the office dim for the whole day or change all the lamps to dim yellow — there should be enough light during the day, and in the evening it is better to reduce the brightness and choose a warmer light. By itself, a warm shade does not solve the problem if the lamp is very bright: time, brightness, and how much light gets into the eyes are important.
"At home, you should stick to about the same time of getting up and going to bed, and darken the bedroom. These habits help maintain a daily rhythm, but they are not a substitute for diabetes treatment or hormonal disorders," the therapist noted.
Bespalova added that a short session of bright light can indeed temporarily reduce drowsiness, but it does not correct the consequences of chronic sleep deprivation. For the workplace, it is more important to choose bright enough, uniform lighting without noticeable flickering and glare, combine the general light with the desktop backlight and position the monitor correctly.
Medical lamps for light therapy, which are used for seasonal affective disorder and circadian rhythm disorders, are a separate tool: they are used as prescribed by a doctor, and an ordinary table lamp with cold light does not become a medical device because of the inscription "daylight".
Before using a powerful lamp, it is worth consulting with a doctor for people with retinal diseases, bipolar disorder, severe photosensitivity, and those who take medications that increase sensitivity to light. If sleep does not improve for a long time, and during the day it constantly makes you sleepy, you should not limit yourself to one change of lighting.
Переведено сервисом «Яндекс Переводчик»
