Young girls who use smartphones and similar devices intensively puberty earlier than those who are more digitally abstinent. This is the result of a study on rats conducted by a team led by Aylin Kilinç Uğurlu from Ankara Bilkent City Hospital. Wirksam ist laut den Wissenschaftlern dabei insbesondere der Anteil des blauen Lichts, das die Displays aussenden.

Ovaries also changed
Prolonged exposure to blue light was associated with an earlier onset of puberty in female rats, which also showed reduced levels of melatonin, increased levels of some reproductive hormones and physical changes in their ovaries. Excessive use of mobile devices has already been linked to sleep disorders in children, but the new findings suggest that there may be additional risks to child development and their future fertility.

The researchers hypothesise that the dislocations are triggered by a disruption of the biological clock, as blue light inhibits the evening rise in the concentration of melatonin, which prepares the body for rest and sleep. In recent years, several studies have found an earlier onset of puberty in girls associated with the COVID-19 pandemic. The association between blue light exposure and reduced melatonin levels suggests that increased screen time, for example during pandemic restrictions, may play a role in this reported increase, according to the study.