Turkish scientists wrote in their study that these mobile touch devices emit high-energy, short-wavelength blue light.

Around the world, preteens are reaching puberty earlier than before, usually due to the brain signaling the sex organs earlier than it should, but other causes include endocrine-disrupting chemicals in food, plastics, and personal-care products; obesity; a rich diet; and even stressful or abusive home environments.

Sometimes it may be due to genetics, or rarely, to a problem in the brain, such as an injury or tumor, or in the thyroid, adrenal, or sex glands. Now, scientists in Turkey have documented another possible cause – exposure to blue light from smartphones or tablets, which led to precocious puberty in male rats. The researchers who recently presented their findings at the 61st Annual European Society for Pediatric Endocrinology Meeting in the Hague were the first to investigate the link between blue-light exposure and early puberty in male rats. They published their study in the journal Frontiers in Endocrinology under the title “Endocrine Disruptors Affecting the Human and Companion Animal Endocrine Functions – Similarities and Indicators in ONE Health Concept. The research shed light on how environmental factors, such as screen time, impact early puberty and testicular tissue. The main source of natural blue light during the day is the sun. It improves cognitive functions, mood, and alertness in the daytime. However, artificial blue light sources at night, such as fluorescence, light-emitting diodes (LED), and TV screens have become prominent throughout the previous century. During the last decade, people of all ages have expanded the usage of touchscreen devices, like tablets and smartphones. These mobile devices emit high-energy, short-wavelength blue light, they wrote. “Because of the reduced eye-screen distance, blue-light exposure is more substantial with these items,” the researchers wrote. “In recent years, the age of use of these devices in children has fallen rapidly. We know that blue light at night has a suppressive effect on melatonin, and – in comparison to the impacts of other light wavelengths – blue light had the most suppressive effect on melatonin. It is also a stress factor and induces oxidative processes in tissues.” Several studies have reported increases in early puberty onset for both girls and boys during the COVID-19 pandemic, as children increased their use of blue light-emitting devices, but this is very difficult to investigate in children.

https://www.jpost.com/health-and-wellness/article-760790