General, Research, Technology

Why do you need to sleep in the dark?

Imagine the night sky. What is it like? In fact, urban residents have not seen a real dark sky for a very long time. The reason lies in light pollution caused by the abundance of artificial lighting. It is possible that seeing the sky as it should be in the dark, many will not believe their eyes and will not recognize the Milky Way. So, according to the atlas of the night sky, which was published in June 2019, 80% of the world's inhabitants live under sky polluted by light. Moreover, night lighting, whether it is light from street lamps, computer screens or smartphones, causes serious harm to health, depriving people of a healthy night's rest.

Earth light seen from space

Why immerse your bedroom in the dark?

A whole string of scientific research is dedicated toproblems associated with artificial lighting and its impact on human and animal health. Artificial light negatively affects the work of circadian rhythms - circadian rhythms with a period of about 24 hours, the work of which determines the time of sleep and wakefulness, as well as regulate the vital activity of the body. So, in mammals, the work of circadian rhythms controls body temperature, hormone secretion, and the functioning of the immune and digestive systems. The abundance of light in the dark leads to a malfunction of circadian rhythms and regular lack of sleep, which causes an increased risk of obesity, type 2 diabetes, breast cancer, prostate cancer, depression and insomnia.

Read more articles about research results on the effect of artificial lighting on health on our channel in Yandex.Zen

According to the results of the study,published in Cancer Research in 2014, women living in areas of California in the most lighted areas are at increased risk for developing breast cancer. A similar relationship between outdoor lighting and the level of diagnosis of breast cancer is observed not only in the United States, but throughout the world. So, Israeli scientists in March last year reported an increase in the incidence of prostate cancer in areas with the highest coverage. According to the results of another study, resistance to the chemotherapeutic drug doxorubicin increases in the presence of artificial light. Also, in animals that are regularly exposed to artificial light at night, tumors develop faster than those that are constantly in the dark.

Agree, it’s quite difficult to fall asleep when it’s very light around

According to Discover, Stephen Hill, ChairmanBreast Cancer Research Department at Tulane University, advises you to buy blackout curtains that do not allow light to pass through, and also to sleep in a mask. In his opinion, even when the eyelids are closed, the faint light from the lanterns penetrating the bedroom can reach the retina and disrupt the circadian rhythms. However, cancer is far from the only side effect that is believed to be associated with exposure to night light on the body. Randy Nelson, a professor of neuroscience at Ohio University, has published more than two dozen studies in mice and hamsters. The results showed that artificial night lighting increases body weight and causes concern. Satellite studies of outdoor lighting have also revealed an increased risk of obesity in people who live in highly lit areas. Moreover, in recent years, a large number of studies have come out that show the relationship between aging and artificial lighting.

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Today, the Milky Way is hidden from a third of the world's population

However, not all scientists shareStephen Hill's point of view. So, according to Mariana Figueiro, professor of the Lighting Research Center at the US Polytechnic Institute, in order for artificial lighting to have such a detrimental effect on health, it is necessary to be exposed to artificial light for a long time. One way or another, in order to confidently state that night illumination causes cancer, it is necessary to conduct additional randomized trials with a large sample. However, today scientists know for sure that artificial lighting disrupts the work of circadian rhythms. So it is better not to take risks and hang blackout curtains in the bedroom.